Raichlen Links Sedentary Habits to Rising Dementia Risk

雷克兰指出久坐习惯增加痴呆症风险 每天久坐12小时会使痴呆症风险增加约60%，但每日短暂的活动与复杂运动可使神经发生翻倍并维持认知功能。 在本期节目中，进化生物学家兼神经科学家戴维·雷克兰（Dr. David Raichlen）探讨了现代久坐行为与椅子如何违背人类的进化机制，从而导致痴呆症和认知衰退风险上升。他阐明衰老的大脑仍保有神经可塑性，并指出体力活动——尤其是结合了空间导航或认知挑战（如定向越野和持拍球类运动）的活动——能够刺激BDNF分泌并驱动神经发生。对话强调，无需严苛极端的运动训练，仅通过日常微小的活动干预、频繁中断久坐、充足睡眠以及稳固的社交纽带，即可获得显著的认知与心血管益处。 现代久坐习惯正加剧脑健康危机：每天久坐12小时相比9小时，患痴呆症的风险增加约60%；而事实上，约40%的痴呆风险可以通过调整生活方式与增加活动量来预防。 (0:00) 成人大脑依然具备神经可塑性与神经发生能力。规律运动能促使骨骼肌释放肌因子并显著提高脑源性神经营养因子（BDNF）水平，如同天然肥料般促进海马体新神经元的生长与存活。 (9:06) 将身体运动与空间导航或复杂认知任务结合（例如越野识途定向运动），相比单纯进行机械式锻炼，能使新生神经元的生长与存活率提升整整一倍。 (18:47) 打破久坐状态无需长时间高强度训练：日常进行1至2分钟的高强度“运动零食”（如爬楼梯、极速快走），或每静坐20分钟起身走动2分钟，即可显著改善代谢指标并大幅降低心血管及全因死亡风险。 (39:15)

University of Southern California professor David Raichlen argues that modern sedentary habits conflict with human evolutionary biology, driving an escalating cognitive health crisis that can be largely mitigated through routine movement and mentally demanding physical activity. Evolutionary Mismatch and Sedentary Dementia Risks (0:00) Human physiology evolved under constant physical exertion, with ancestral hunter-gatherers traveling significant distances daily to forage. Modern society has engineered movement out of everyday life, resulting in widespread physical inactivity: only 25% of U.S. adults achieve the recommended 150 minutes of weekly moderate-to-vigorous exercise, and older American adults average just two to four minutes per day. By contrast, field studies of the Hadza in Tanzania show adults logging 15,000 to 20,000 steps daily and seniors maintaining 60 to 80 minutes of daily moderate-to-vigorous activity, exhibiting exceptionally low rates of hypertension and lipid disorders. Raichlen points out that prolonged sitting deactivates lower-body muscles, preventing them from clearing triglycerides and signaling the body to downregulate tissue maintenance. Epidemiological data indicates a steep, non-linear dementia risk curve associated with sitting: sitting 10 hours per day compared to 9 increases dementia risk by roughly 10%, while reaching 12 hours spikes the risk by approximately 60%. While Hadza individuals rest for comparable total hours, they utilize active postures like squatting or kneeling that sustain continuous low-level muscular engagement. Neuroplasticity and the Biology of Movement (2:10) Overturning the historical assumption that the adult brain is structurally fixed and inevitably declines after age 20, modern neuroscience shows that the brain retains neuroplasticity through adult neurogenesis. Physical activity acts as a primary trigger for this process by boosting cerebral blood flow and prompting contracting muscles to release myokines into the bloodstream. These signaling proteins cross the blood-brain barrier and stimulate Brain-Derived Neurotrophic Factor (BDNF), which supports the birth, survival, and circuit integration of new neurons in memory centers like the hippocampus. While endurance exercise elevates BDNF and resistance training stimulates separate growth-factor pathways, Raichlen notes that pairing physical exertion with cognitive engagement yields amplified results. In rodent experiments led by Gerd Kempermann, combining running wheels with enriched, complex environments doubled the survival rate of new neurons compared to exercise or enrichment alone. Similarly, human trials show that orienteering—navigating unfamiliar terrain at speed using maps—produces superior memory and executive function gains compared to standard hiking or control routines. Actionable Interventions: Micro-Habits and Environmental Modifiers (39:15) Raichlen emphasizes that substantial cognitive and cardiovascular gains do not require grueling regimens. The steepest reduction in health risk occurs when transitioning from zero activity to modest movement, such as 2,000 to 4,000 steps per day, after which returns diminish incrementally. Furthermore, breaking prolonged sitting with 'vigorous intermittent lifestyle physical activity' (VILPA)—one- to two-minute bursts of brisk stair climbing or fast walking—or interrupting sitting every 20 minutes with a two-minute walk markedly improves metabolic markers like insulin sensitivity and blood lipids. However, environmental context matters. Exercising in areas with moderate-to-high air pollution suppresses the neuroprotective benefits of exercise because increased respiration draws fine toxic particles deeper into the body. Conversely, natural outdoor settings enhance mood and emotional resilience, and complex social sports like tennis or pickleball combine high-speed visual processing, strategic decision-making, and communal interaction. Broader Modifiers: Sleep, Alcohol, and Social Bonds (46:08) Raichlen highlights that an estimated 40% of dementia cases are tied to modifiable lifestyle factors, where physical activity operates alongside diet, sleep hygiene, and social support. Chronic alcohol intake exceeding one drink per day for women or two for men accelerates tissue atrophy, while sleep follows a U-shaped risk pattern: sleeping fewer than 7 or more than 9 hours correlates with higher dementia risk. Adequate sleep provides a critical metabolic window for the brain to clear waste, including beta-amyloid plaques. Social connection serves as an additional buffer against neurodegeneration. In older adults, bereavement and loneliness frequently induce depressive states that compromise attention mechanisms and mimic dementia, termed 'pseudodementia.' High-quality relationships and lifelong education build cognitive reserve—the structural and synaptic resilience that allows the brain to withstand tissue loss without manifesting functional deficits. With U.S. Alzheimer's and dementia cases projected to rise from 6 million to 13 million over the next 25 years—and annual domestic care costs estimated to reach $1 trillion by 2050—Raichlen contends that preventative lifestyle modifications remain humanity's most effective defense given the limited efficacy of pharmaceutical treatments. However, population-level adherence remains an unresolved challenge as developing nations increasingly mirror Western sedentary routines.

南加州大学人类进化生物学与神经科学教授David Raichlen指出，现代久坐的生活方式与人类进化形成的生理机能严重冲突，是导致大脑认知衰退和痴呆风险攀升的核心诱因；但科学证实成年大脑依然保持神经可塑性，通过减少静坐时间、进行结合认知挑战的身体活动并改善睡眠与社交，约40%的痴呆症风险可以通过生活方式的改变加以预防。 进化机制错位与久坐不动的大脑危机 (0:00) Raichlen教授指出，人类生理机能是在约200万年前转向狩猎采集的过程中演化形成的，持续的高水平日常体力活动是维持机体与大脑正常运转的基准需求。对坦桑尼亚Hadza狩猎采集部落的研究显示，其成年人每日平均行走1.5万至2万步，70至80岁的老年人每日仍能维持60至80分钟的中高强度身体活动（MVPA）。与之形成鲜明对比的是，现代工业社会陷入了严重的体力活动赤字：美国仅有25%的成年人达到每周150分钟的推荐运动标准，老年人群体的日均中高强度活动更是骤降至2至4分钟。 长期静坐会触发人体的“能量最小化”机制，使骨骼肌处于闲置状态，导致血液中循环的甘油三酯无法分解为脂肪酸供能，进而引发脂质在血管内积聚并加速大脑衰退。流行病学数据显示，每日静坐时间超过9至9.5小时后，痴呆风险开始呈非线性加速上升：相比每日坐9小时，静坐10小时会使痴呆风险增加约10%，而静坐12小时则会使该风险激增约60%。Hadza人每日的总休息时间虽与现代西方人相近，但他们多采取深蹲或跪坐等能够维持低水平肌肉收缩的主动姿势，而约5000年前才广泛出现的椅子则彻底消除了下肢肌肉的激活需求。 成人神经可塑性与运动的生物催化机制 (2:10) 长期以来，神经科学界普遍认为大脑结构在成年后即定型并不再改变，20岁后便步入不可逆的萎缩进程。现代研究彻底推翻了这一假设，证实成年大脑依然具备生成新神经元的能力（神经发生）。海马体作为大脑颞叶深处负责工作记忆、情景记忆和空间导航的核心枢纽，是阿尔茨海默病等神经退行性疾病最早且最严重受损的区域。实验表明，运动干预不仅能增加啮齿动物与人类海马体的体积，还能巩固负责规划与决策的前额叶皮层。目前全美约有600万名阿尔茨海默病患者，预测25年内将增至1300万人，全球患病人数预计在30年内达到1.5亿人。 运动改善脑健康的生理通路主要依赖肌脑轴的生化级联反应。身体活动能显著增加大脑血流量，为神经元运送充足的氧气和营养物质。骨骼肌收缩时会释放专属性信号蛋白——肌因子（myokines），该物质穿过血脑屏障后会促使大脑上调脑源性神经营养因子（BDNF）的表达。BDNF被称为中枢神经系统的“生物肥料”，它不仅能直接诱导海马体产生新神经元，还能确保新生细胞顺利存活并整合进现存的神经回路中。此外，运动能激活内源性大麻素系统，促成神经递质奖赏并提升警觉性，从而带来即时的情绪提振与专注力改善。 运动结合认知负荷对神经元存活的双重增效 (18:47) 单纯的身体活动虽能提供基线神经保护，但若在运动中融入复杂的认知与空间挑战，将产生倍增的生物学效益。Gerd Kempermann主导的啮齿动物实验证实，将转轮跑步与复杂环境挑战（配备玩具与多维结构）相结合的实验组，其大脑新神经元的生成与存活数量是单纯转轮跑步或单纯环境刺激组的两倍。在人体随机对照试验中，研究人员对比了定向越野组、户外徒步组与对照组，发现需要实时借助地图与指南针在崎岖野外地形中高速导航的定向越野受试者，在记忆力与执行功能测试中的表现显著优于单纯徒步组。 从进化生物学视角分析，人类祖先在自然环境中的奔跑与行走始终带有明确的资源搜寻目的，体力付出必然伴随着复杂的空间认知运算。因此，像定向越野或网球、匹克球这类结合了有氧代谢、实时战略决策与快速反应的球拍类运动，更能模拟这种演化机制，同时其社交属性也强化了人际连接。“绿色运动”研究表明，在自然绿地和公园中锻炼比在室内跑步机上能带来更显著的情绪提振和抗焦虑效果。不过Raichlen教授指出，在受到中度至重度空气污染的环境中运动，由于呼吸急促导致细微有毒颗粒吸入量剧增，会抵消运动原本所能带来的大脑认知与结构保护效益。 破除完美主义与碎片化运动零食干预 (39:15) 许多久坐人群在建立运动习惯时容易陷入“非全即无”的心理陷阱，将锻炼视为需要耗费大量时间与高强度付出的沉重负担，这种心理阻力往往导致彻底的拖延与逃避。然而流行病学证据明确显示，身体活动的健康收益呈高度非线性特征：从零运动基础过渡到每天完成2000至4000步，即可捕获最大幅度的相对心血管与脑健康保护收益，随后的增量收益则进入边际递减曲线。将宏大目标拆解为细微的微习惯（例如步行去购买午餐而非使用手机外卖），能有效消除启动阻力。 对于无法抽出整块时间锻炼的现代职场人群，Raichlen教授提倡采用碎片化的“剧烈间歇性生活方式身体活动”（VILPA，即“运动零食”）。研究证实，日常穿插进行1至2分钟的高强度活动脉冲（如快速爬楼梯、极速步行，其强度以无法在移动中同时顺畅交谈或唱歌的“交谈测试”为界），能够显著降低心血管疾病发病率和全因死亡率。实验室随机对照试验表明，在长达8小时的静态办公日中，每隔20分钟进行2分钟的短暂停顿步行，便能大幅改善胰岛素敏感性，并有效平抑餐后血糖与甘油三酯水平的激增。 认知储备与健康老龄化的生活方式支柱 (46:08) Raichlen教授提出，健康老龄化依赖于三大核心支柱：身体活动、合理饮食与人际社交。南美洲Tsimane原住民的长期追踪研究显示，该群体几乎没有心血管疾病、2型糖尿病或痴呆症病例，这表明诸多老年慢性疾病主要源于现代工业化生活模式，而非生理衰老的必然结果。通过终身教育、复杂导航挑战以及持续的心智刺激，大脑能够建立起深厚的“认知储备”，增加神经组织体积并强化突触连接，使得个体在遭遇年龄相关性脑组织萎缩时，仍能调用备用通路维持正常的日常生活自理能力。 在日常习惯方面，不良睡眠与过量饮酒是加速大脑老化的关键推手。睡眠与痴呆风险呈现明显的U型曲线，每晚7至9小时睡眠的风险最低；深睡眠阶段大脑会激活类淋巴系统清除β-淀粉样蛋白等代谢毒性斑块，睡眠不足（少于7小时）会剥夺这一清洁窗口，而睡眠过长（超过9小时）往往是临床抑郁症或极度缺乏活动的代偿表征。在饮酒方面，女性日均超1杯、男性超2杯即会加剧脑组织萎缩风险。饮食模式上，以全谷物、豆类和植物性天然食物为主、限制精制糖与红肉摄入的地中海饮食，被长期观察性数据证实最有利于维持脑结构健康。此外，高质量的亲密社交关系能显著缓冲认知衰退，而晚年丧偶引发的重度抑郁往往会因破坏注意力机制而诱发“假性痴呆”。 Raichlen教授指出，鉴于目前阿尔茨海默病的药物治疗效果有限，且美国预计到2050年每年在痴呆症护理上的支出将高达1万亿美元，通过生活方式干预来延缓发病已成为最关键的公共卫生防线。然而，发展中国家当前正在快速接纳西方高热量饮食与久坐模式，全球人口的整体运动达标率在过去二十年间基本处于停滞状态。如何在现代城市规划、工作环境以及日常制度中切实破除久坐依赖，仍是阻碍全民脑健康改善的最大现实瓶颈。

## Background 该视频由 YouTube 频道 The Diary Of A CEO（主持人 Steven Bartlett）于 2024 年 2 月 8 日发布。访谈邀请了南加利福尼亚大学人类进化生物学与神经科学专家 David Raichlen 教授，结合人类演化历程与脑科学最新发现，深入探讨运动、久坐及现代生活方式对大脑健康与阿尔茨海默病预防的深远影响。 ## TL;DR 本期节目颠覆了成人大脑不可逆衰退的传统观念，指出规律运动能通过刺激肌细胞因子和 BDNF（脑源性神经营养因子）促进海马体神经发生，并大幅增强大脑认知储备。访谈通过非洲哈扎（Hadza）狩猎采集部落的生理数据揭示：现代人久坐突破 9.5 小时后痴呆风险呈指数级暴增，而人类身体的演化机制决定了肌肉需要持续的低负荷刺激。专家强调，结合空间认知挑战的运动（如定向越野、球拍类运动）与碎片化的高强度运动（VILPA/运动零食）能成倍放大脑部获益；同时，终身学习、7至9小时优质睡眠、高质量社交连接以及地中海饮食，是构筑抵御认知衰退与阿尔茨海默病的核心防护屏障。 ## Atmosphere & style 整场对话充满求知欲与紧迫感，主持人 Steven Bartlett 敏锐务实的追问与 David Raichlen 严谨而通俗的演化生物学剖析相得益彰。从揭露久坐导致失智风险剧增的冷峻现实，到引用哈扎部落田野趣事与神经可塑性证据的顿悟时刻，对话节奏张弛有度。现场既有对全球认知衰退危机的深切警示，又充溢着行动主义的乐观力量，带给观众极具说服力且能立刻付诸实践的健康启迪。 ## Bulletin - [58:20](https://www.youtube.com/watch?v=WLWbFVKFffM&t=3500s) 久坐时间与失智症发病风险呈非线性指数关系：每日久坐超过 9 至 9.5 小时即迎来风险转折点，每天坐 10 小时相比 9 小时风险上升 10%，而一旦达到 12 小时，失智风险将急剧暴增 60%。 - [17:33](https://www.youtube.com/watch?v=WLWbFVKFffM&t=1053s) 运动通过肌肉收缩分泌肌细胞因子（myokines）并上调脑源性神经营养因子（BDNF），若将耐力运动与空间导航或即时决策结合（如定向越野、球拍类运动），大脑新生神经元的生长存活率可达到单纯跑步的两倍。 - [31:59](https://www.youtube.com/watch?v=WLWbFVKFffM&t=1919s) 坦桑尼亚哈扎人与玻利维亚齐曼内人等狩猎采集部落极少患有动脉硬化、心血管疾病及阿尔茨海默病，证实了约 40% 的痴呆症风险可通过生活方式预防，退行性慢性病绝非人类衰老的必然宿命。 - [50:54](https://www.youtube.com/watch?v=WLWbFVKFffM&t=3054s) 空气污染显著削弱运动的神经保护收益：剧烈运动大幅增加通气量，在中度至重度空气污染环境中户外运动，会直接抵消原本对大脑容积保持和认知防衰的促进效果。 ## Key takeaways - [02:10](https://www.youtube.com/watch?v=WLWbFVKFffM&t=130s) 成年后的大脑依然具备神经发生（neurogenesis）与神经可塑性，主管记忆与空间导航的海马体仍能持续分化出新生神经元，规律运动是激发这一过程最核心的手段。 - [10:10](https://www.youtube.com/watch?v=WLWbFVKFffM&t=610s) 运动重塑大脑的生化轴：肌肉收缩释放的肌细胞因子（myokines）穿透血脑屏障刺激 BDNF 大幅分泌，充当神经元的“天然化肥”，确保新生神经元长期存活并嵌入认知回路。 - [07:42](https://www.youtube.com/watch?v=WLWbFVKFffM&t=462s) 人体生理默认以日行近 20 公里的高活动量为出厂设置；由于人体遵循“能量最小化”原则，长期缺乏负荷刺激会导致心脏、骨骼肌和大脑神经组织被主动回撤资源并出现萎缩。 - [26:30](https://www.youtube.com/watch?v=WLWbFVKFffM&t=1590s) 运动收益存在明显的边际递减效应，公共卫生最大的健康回报出现在从零运动提升至每日 4,000 至 5,000 步的阶段，初学者无需被极高步数目标劝退即可建立扎实防线。 - [36:12](https://www.youtube.com/watch?v=WLWbFVKFffM&t=2172s) 哈扎人全天总休息时长与现代人接近，但其采用蹲姿、跪姿等保持肌纤维持续微收缩的“主动休息姿态”，而现代椅子彻底卸载了下肢负荷，直接导致甘油三酯代谢停滞并损伤内皮细胞。 - [40:29](https://www.youtube.com/watch?v=WLWbFVKFffM&t=2429s) 将久坐切碎的“运动零食”与偶发性高强度活动（VILPA）具强大代谢价值：每隔 30-45 分钟进行 1-2 分钟快速爬楼梯或竞走，即可显著平抑餐后胰岛素峰值并加快血脂清除。 - [44:27](https://www.youtube.com/watch?v=WLWbFVKFffM&t=2667s) 终身学习与高认知负荷活动能够构建强大的“认知储备”，增加海马体体积与突触冗余度，即使晚年发生生理性脑萎缩也不会轻易跌破临床失智的临界阈值。 - [46:37](https://www.youtube.com/watch?v=WLWbFVKFffM&t=2797s) 睡眠与大脑健康呈现 U 型曲线：每晚 7 至 9 小时规律睡眠是大脑淋巴系统清除淀粉样蛋白等代谢毒素的排毒窗口，常年睡眠不足或因潜在抑郁导致的嗜睡均与认知衰退风险上升相关。 - [48:22](https://www.youtube.com/watch?v=WLWbFVKFffM&t=2902s) 高质量的社会连接是健康老龄化的三大基石之一；丧偶或孤独引发的抑郁症常伴随注意力与编码功能障碍，极易伪装成假性痴呆，需及早通过心理及身体活动干预。 - [55:52](https://www.youtube.com/watch?v=WLWbFVKFffM&t=3352s) 运动可激活内源性大麻素系统带来愉悦奖赏（跑步者高潮），初学者因初期神经内分泌尚未自适应调节且易运动过量，需坚持度过适应期方能触发正向神经反馈循环。 - [01:01:45](https://www.youtube.com/watch?v=WLWbFVKFffM&t=3705s) 对抗认知退化不存在单一的补脑神奇药丸，以植物性食物、全谷物和豆类为主的地中海饮食结构，通过抗炎、抗氧化与改善外周胰岛素敏感性协同守护脑血管健康。 - [01:03:07](https://www.youtube.com/watch?v=WLWbFVKFffM&t=3787s) 打破“非全即无”的心理门槛是维持大脑活力的关键：将每日久坐从 12 小时缩短至 8-9 小时，其执行阻力远小于跑马拉松，任何微小的离椅活动都能有效改变神经老化轨迹。 ## Detailed walkthrough ### [00:00](https://www.youtube.com/watch?v=WLWbFVKFffM&t=0s) 久坐的认知危机与前瞻 对话开篇直击现代人最严峻的健康隐患之一：久坐与失智症（认知障碍症/老年痴呆）之间的惊人联系。研究数据显示，每天坐 10 小时相比每天坐 9 小时，罹患失智症的风险会上升约 10%；而一旦久坐时间攀升至每天 12 小时，这一患病风险将暴增约 60%。面对主持人震惊的追问，南加利福尼亚大学（USC）人类进化生物学、运动生理学与神经科学教授 David Raichlen 强调，随着全球人口老龄化加剧，大脑健康问题已迫在眉睫。 健康老龄化主要依赖三大基石：饮食（diet）、身体活动（physical activity）以及社交联系（social connections）。拥有更强社交纽带的人往往展现出更优越的脑健康表现；反观不良生活习惯，每天饮酒超过一杯便会对健康造成负面损伤并可能导致脑萎缩；睡眠则是另一个关键因素，无论过少还是过多的睡眠都与认知衰退风险升高密切相关。 - **久坐与失智风险跃升**：9 小时为基准，10 小时风险增加约 10%，12 小时激增约 60%。 - **全球健康危机**：美国目前已有 600 万人确诊阿尔茨海默病或相关失智症，预计未来 25 年内翻倍达到 1300 万；全球范围内，未来 30 年内失智症患者人数预计突破 1.5 亿。 - **运动达标现状严峻**：官方建议成年人每周应保持 150 分钟中高强度身体活动，但全美仅有 25% 的成年人能够达标；老年群体每天的中高强度活动甚至仅有可怜的 2 至 4 分钟。 - **居家远程办公隐患**：长期静态居家办公脱离了人类身体进化的自然模式，对生理健康构成了深层挑战。 ### [02:10](https://www.youtube.com/watch?v=WLWbFVKFffM&t=130s) 传统观念的颠覆：成年后的大脑依然具备可塑性 主持人请 David Raichlen 总结其科研的核心使命。Raichlen 指出，自己的毕生研究旨在揭示：运动及广泛的生活方式究竟“如何”以及“为何”塑造人类大脑健康，尤其是探寻如何通过生活方式干预来延缓和预防衰老引发的神经退行性疾病。 许多人长期将大脑视为颅骨内一块无法主动锻炼的“豆腐块”，认为神经系统的发育早在童年和青少年期就已定型，到了 20 岁之后，大脑便步入一条只缩不长、不可逆转的下坡路。Raichlen 澄清道，过去数十年的神经科学突破彻底推翻了这一悲观教条。成年后的大脑依然具有生成新生神经元（即神经发生，neurogenesis）的能力，尤其是在主管记忆的核心中枢——海马体（hippocampus）中。通过规律的身体活动激发神经新生，很可能是人类抵抗衰老相关认知衰退与阿尔茨海默病的最有力武器。 ### [04:41](https://www.youtube.com/watch?v=WLWbFVKFffM&t=281s) 神经发生与海马体的结构与功能 在探讨人类脑结构如何改变之前，Raichlen 详细介绍了动物模型中观察到的确凿证据。在小鼠和大鼠的研究中，科学家可以通过神经解剖直接观测脑部微观变化：当给啮齿动物提供滚轮或安排跑步机训练时，其大脑会迅速孕育出大量新生的神经细胞，这些新神经元不仅能够长期存活，还会真正整合并嵌入到海马体的神经网络中。 神经元（neuron）作为大脑中最核心的细胞结构，负责在不同脑区之间传递与交流电化学信息。而深嵌于大脑颞叶内侧的海马体，形态弯曲如同一只海马，是大脑的信息枢纽： ```mermaid flowchart TD accTitle: 海马体核心功能与退化后果示意图 accDescr: 展示海马体在工作记忆、事件记忆和空间导航中的核心地位，以及阿尔茨海默病破坏海马体后导致的后果。 subgraph Hippocampus["核心结构：海马体 (Hippocampus)"] F1["工作记忆 (Working Memory)"] F2["事件长时记忆 (Event/Episodic Memory)"] F3["空间导航 (Spatial Navigation)"] end subgraph Disease["疾病侵袭"] AD["阿尔茨海默病 / 神经退行性变"] end subgraph Outcome["功能损害"] Loss["记忆严重缺损与日常认知障碍"] end Hippocampus --> F1 Hippocampus --> F2 Hippocampus --> F3 AD -.->|优先侵蚀| Hippocampus Hippocampus -.->|萎缩衰退| Loss ``` 海马体深度掌控着工作记忆（短期信息的维持与快速调用）、个人经历的事件记忆（episodic memory）以及在三维世界中穿梭探索的空间导航能力（spatial navigation）。正因其功能极其繁重且关键，阿尔茨海默病等退行性病变往往最先破坏该区域，从而引发严重影响日常生活的失忆症状。 在物种对比上，啮齿动物模型中由运动诱导的新生神经元主要局限于海马体；而在人体影像学（如 MRI）研究中，规律运动的影响更为广泛。人体不仅展现出海马体体积的增加与保持，更在前额叶皮层（frontal lobe）观察到明显的脑容积保存与增长，而前额叶正是统领决策、长期规划和执行功能（executive cognitive function）的指挥中心。 ### [07:42](https://www.youtube.com/watch?v=WLWbFVKFffM&t=462s) 进化视角：为什么运动能拯救人类的大脑？ 理解运动与脑健康的深刻羁绊，必须回溯人类进化的历程。动物生存皆需移动觅食，但人类身体活动模式在约 200 万年前发生了极其剧烈的蜕变。 在这个关键时间节点，早期人类祖先告别了类人猿式的林栖树居生活，全面转向狩猎采集（hunter-gatherer）生活方式。人类单日的活动距离呈爆发式增长，日均徒步行进与奔跑常常超过 20 公里，且运动强度显著提高。人类的整个生理系统、心血管网络以及脑神经回路，正是在“每日持续大量中高强度身体活动”的严酷压力下协同演化而来的。 在生物进化长河中，这种高强度的运动模式才是人类生理的“默认出厂设置（normal condition）”。现代文明中出现的严重久坐与极度缺乏身体活动，实际上是违背人类演化生理机制的异常状态。从群体公共卫生的宏观角度来看，缺乏运动必然导致关键脑区（如海马体）萎缩、整体认知能力下滑以及失智症风险倍增。尽管个体发病风险受到遗传与多元环境因素的共同影响，但从生物学因果关系来看，积极进行体育锻炼依然是每个人抵御认知衰退、为大脑构筑防护屏障最确凿且有效的手段。 ### [10:10](https://www.youtube.com/watch?v=WLWbFVKFffM&t=610s) 运动改造大脑的生物学机制：肌细胞因子与 BDNF 主持人好奇地追问，既然运动能预防痴呆甚至促使大脑特定区域生长，那么身体内部究竟发生了什么？受访专家解释说，运动带来的内部反应非常丰富且有趣。首先，运动会促进流向大脑的血液循环，不仅为脑细胞运送关键营养物质，还维持神经元的正常功能运转。更关键的机制在于，肌肉在收缩运动时会产生并分泌一类名为肌细胞因子（myokines）的蛋白质。这些蛋白质通过血液循环穿透屏障到达大脑，与神经元发生相互作用，进而上调神经滋养因子的表达。 在这些神经滋养因子中，最引人瞩目的是脑源性神经营养因子（BDNF）。专家形象地将 BDNF 比喻为脑细胞或新生神经元的“化肥”。当运动促使 BDNF 水平大幅提升时，它不仅能刺激新生神经元的产生（神经发生），还能为这些年轻细胞提供存活保障，帮助它们顺利嵌入并整合到既有的大脑神经网络与认知处理回路中。 ```mermaid flowchart TD accTitle: 运动促进大脑神经生长的生物机制 accDescr: 展示运动如何通过血流增加与肌肉释放肌细胞因子，最终促使BDNF上调并推动新神经元存活与整合。 subgraph Periphery["外周机体反应"] A["体力运动与肌肉收缩"] --> B["全身与脑部血流增加"] A --> C["肌肉释放肌细胞因子 (Myokines)"] end subgraph Brain["中枢神经系统反应"] B --> D["提供氧气与营养维持神经元"] C --> E["跨屏障作用于神经元"] E --> F["大幅上调脑源性神经营养因子 (BDNF)"] F --> G["充当'大脑化肥'"] G --> H["促进新神经元诞生"] G --> I["帮助新神经元存活并融入回路"] end ``` ### [11:03](https://www.youtube.com/watch?v=WLWbFVKFffM&t=663s) 演化视角：人体生理为什么默认“必须运动”？ 面对如此显著的益处，主持人半开玩笑地提出了一个直觉性疑问：“大脑为什么不能自发进行自我修复和扩张，而非要逼着我们去运动？”专家笑着承认：“如果真能那样确实太棒了”，但人体的生理机制并非凭空设计，而是深深植根于演化历史中。 在长达两百万年的演化历程中，人类的自然生存状态就是高强度的体力活动——祖先必须不断奔波才能捕获猎物、采集果实并维持生存。因此，人体的全部生理结构与调节机制，都是在适应“频繁身体活动”的前提下形成的。在极其漫长的时间里，人类根本不需要去演化出适应“极度缺乏身体活动”的机制。现代人经历的身体活动断崖式暴跌，其实仅仅发生在最近这几百年间，这在演化尺度上不过是一瞬间，生物体根本来不及产生相应的演化适应。 - **工业革命的影响**：两百年前机械化浪潮爆发，大幅削减了人类通过高强度劳作获取食物与基本生存资料的必要性。 - **现代工作与生活形态**：过去五六十年来，大量需要伏案工作的办公室岗位取代了体力劳动；汽车的普及彻底改变了通勤方式；舒适的沙发、电视机以及如今极具吸引力的智能手机和电脑屏幕，把闲暇时间牢牢绑定在静态坐姿上。 ### [12:54](https://www.youtube.com/watch?v=WLWbFVKFffM&t=774s) 久坐成瘾与人体“能量最小化”原则 关于现代人的久坐行为，专家指出，由于学界系统测量人们静坐时长的时间并不长，很难得出长期的历史增幅曲线，但目前的客观现状极其严峻：如今成年人平均每天静坐时间长达 9 到 10 个小时。这种极度的静态生活方式，直接对应着极低的体力活动水平。 尽管过去二十多年来公共卫生领域不遗余力地普及“运动有益健康”、“必须多活动”的宣教口号，但数据显示，全美仅有大约 25% 的成年人能够达到官方推荐的基础健康活动标准，而且这个数字在过去 20 年间几乎停滞不前。 主持人由此联想到身体的适应机制：身体所有器官和组织似乎都必须依赖外部刺激才能生长。正如去健身房举铁肌肉才会增大，而如果突然剧烈加练（比如自己曾突然每周踢四次足球，脚部肌肉由于承载不了剧烈需求而几乎“爆炸”），身体就会遭遇严峻挑战；大脑同样遵循“用进废退”（Use it or lose it）的铁律。 专家对此高度赞同，指出人体本质上是一个极度高效的“能量最小化机器”（energy minimizers）： - **肌肉萎缩**：维持肌肉组织需要消耗大量能量，一旦长期不用，身体为了节能便会主动让其萎缩缩小。 - **心血管机能下降**：如果不运动，心脏就没有必要维持强大的泵血压力，毛细血管网络会退缩，心肌组织萎缩，心脏运作效率显著降低。 - **大脑资源回撤**：大脑同样如此。当身体处于静止、不接收环境挑战的信号时，机体便会认为没有必要向维持脑组织耗费昂贵的能量预算，从而导致神经结构缩减与机能退化。 ### [15:24](https://www.youtube.com/watch?v=WLWbFVKFffM&t=924s) 运动类型对比与定向越野带来的认知飞跃 不同类型的运动对大脑的影响是否完全相同？抗阻训练（力量训练）的效果能否等同于户外跑步？专家指出，目前学术界直接对比不同运动类型对大脑益处的严谨研究还相对有限，无法武断判定哪一种绝对“最好”。目前关于耐力运动的有益证据更丰富，这部分是因为在啮齿动物模型中做耐力跑步实验要比做力量抗阻训练容易得多，跨物种转化更方便。不过，力量训练与耐力运动都会对大脑产生积极收益，只是背后依赖的生物通路与机制可能存在差异。 更有趣的前沿方向在于探索不同形式的耐力运动。专家重点分享了一项针对“定向越野”（Orienteering）的最新随机对照试验（RCT）。定向越野要求参赛者在野外依靠一张地图和一个指南针，以最快速度自行规划并穿越未知路线，它巧妙地将耐力奔跑与复杂的空间定向导航、环境感知融合在一起。 | 对比组别 | 核心活动形式 | 认知测试表现（记忆力与执行功能） | |:--- |:--- |:--- | | **对照组** | 维持日常常规生活，不进行额外干预 | 表现基准线，相对最差 | | **徒步组 (Hiking)** | 在自然户外环境中行走徒步 | 认知表现显著优于对照组 | | **定向越野组 (Orienteering)** | 户外奔跑同时结合地图与指北针导航、即时路线决策 | 表现最佳，在徒步组的基础上获得了**额外的认知提升** | 这项研究表明，如果运动本身融入了高密度的认知挑战，其对大脑机能的提振效应会出现实质性的飞跃。 ### [17:33](https://www.youtube.com/watch?v=WLWbFVKFffM&t=1053s) 演化认知模型：挑战性运动为何让大脑成倍获益 从人类演化生态学视角来看，人类祖先在自然栖息地中绝不会为了“锻炼打卡”而无缘无故地奔跑或消耗能量。运动在自然界中必然伴随着明确的生存目的——搜寻食物、水源、柴火或规避掠食者。这意味着在演化长河中，真正的体力活动从来都与复杂的认知挑战（空间记忆、地形判断、追踪与决策）紧密捆绑，二者无法分割。一旦现代人将体能消耗与“解谜式”的脑力挑战结合起来，就会触发更深层次的生物学适应收益，达成“事半功倍”的大脑提振。 这种机制在动物神经生物学研究中同样得到了有力证实。专家援引了神经科学家格德·肯珀曼（Gerd Kempermann）教授团队的一项经典小鼠实验。该实验对比了不同生活环境对新生神经元的影响： 1. **普通对照组**：仅生活在标准普通笼中； 2. **滚轮运动组**：笼内配备转轮供其自由奔跑； 3. **环境丰富组 (Enriched environment)**：笼内设置各种复杂的玩具、攀爬结构和认知挑战，但不配转轮； 4. **复合干预组**：同时提供转轮与丰富刺激环境。 实验结果极为震撼：将“滚轮奔跑”与“复杂探索环境”相结合的复合组小鼠，其大脑新生神经元的生长与长期存活数量，直接达到了单纯跑步组或单纯丰富环境组的**两倍**。这种强烈的协同叠加效应证明，将体能运动与脑力认知挑战相结合，是激发大脑神经可塑性的最强催化剂。 ### [19:59](https://www.youtube.com/watch?v=WLWbFVKFffM&t=1199s) 结合认知挑战与运动：放大神经可塑性与认知增益 在将动物实验中“丰富环境刺激”与“规律运动”协同增效的发现外推至人类生活时，最核心的原则依然是首先让自己动起来。对于目前久坐不动的人群而言，出门步行就是迈向健康最关键的第一步。然而，若目标是追求长寿、幸福以及极致健康的大脑，单纯的机械运动还可以进一步升级。研究开始证实，将身体活动与认知挑战结合，能显著放大运动对大脑尤其是认知表现的促进效果。 实验室环境下的控制研究已经为此提供了有力证据。研究团队曾开发过一款在健身器材上边运动边玩的互动游戏，实验结果表明，这种“运动加认知挑战”的组合模式，对认知功能的提升幅度明显超过了单纯运动或单纯玩游戏。将这一机制转化为日常生活实践，普通人可以通过改变运动形式来主动为大脑增加“空间认知挑战”： - 许多跑者或散步者习惯日复一日重复一两条固定路线，这种自动化模式减少了大脑的认知负荷。 - 尝试探索陌生路线，甚至让自己在安全范围内“迷路”片刻并重新辨认方向返回，能够迫使大脑进行实时的空间导航与环境感知，从而提供更强烈的认知刺激。 ```mermaid flowchart TD accTitle: 运动与认知刺激对大脑机能的增效机制 accDescr: 对比单纯运动、单纯脑力训练与结合两者的综合模式，展示组合训练如何实现更大的认知收益与神经重塑。 subgraph Inputs["干预方式"] A["单纯机械运动\n（如固定路线跑步）"] B["单纯认知挑战\n（如静态智力游戏）"] C["复合型运动\n（运动 + 实时空间导航/决策）"] end subgraph Mechanism["大脑响应过程"] M1["提供基础血流与神经营养因子"] M2["激活神经元回路"] M3["丰富环境刺激 + 神经元新生协同促进"] end subgraph Outcome["最终效应"] R1["基础心血管与情绪收益"] R2["单一技能熟练度提升"] R3["神经可塑性大幅激活\n认知功能与记忆力显著提升"] end A --> M1 --> R1 B --> M2 --> R2 C --> M3 --> R3 ``` ### [21:54](https://www.youtube.com/watch?v=WLWbFVKFffM&t=1314s) 绿色运动的力量：户外自然空间对情绪与大脑的重塑 主持人提到了一个极具现实感的对比：在纽约出差时，自己在酒店房间的跑步机上面壁跑步，而团队成员 Jack 则在中央公园的户外跑步，两者对大脑的滋养是否存在本质差距。从机制上看，室内跑步机更接近实验小鼠在缺乏丰富环境下的单一转轮运动，而户外奔跑则包含了大量复杂的动态感官输入。 当前备受关注的“绿色运动”（Green Exercise）研究领域揭示，在自然或绿色空间（如公园、林间小道）中运动，相比在纯都市街道或室内器械上，能为心理状态带来更大的额外增益。尽管跑步机对于工作节奏紧凑的现代人依然是极好的锻炼工具，但只要环境允许，走向大自然是极具性价比的选择： - 走向户外和绿色植被环境已被明确证实能显著改善情绪、缓解压力并提升整体幸福感（Well-being）。 - 科学界正进一步探索并假设其对于高级认知功能的潜在附加提升。 - 这种机制促使人们打破“跑步机与户外跑步完全等效”的固有认知，在日常决策中更积极地选择融入自然。 ### [24:06](https://www.youtube.com/watch?v=WLWbFVKFffM&t=1446s) 晨间运动对全天认知的激活与分子回报机制 许多人在实践中发现，录制播客或进行高强度脑力活动之前若先进行锻炼，思维运转会极其顺畅，大脑与表达的协同行云流水；反之，若未运动直接开始工作，往往会感觉“大脑里的词句很难顺畅地传达到嘴边”。这种生理体验是许多神经科学家深入研究该领域的契机——即使是研究者本人，若早晨没有跑步，全天也会感觉情绪焦躁、不易相处。 这种运动带来的“认知破局”主要源自大脑底层奖赏通路的全面激活： - 身体运动激活了大脑的奖赏中枢（Reward Centers），从而显著提高个体的唤醒水平（Arousal）。 - 奖赏回路产生愉悦感与从容感，帮助人摆脱内心的杂念反刍（Ruminating），更加专注于当下（Present）。 - 这种心理状态建立在底层的分子回报基础之上：运动能够刺激内源性受体（其分子作用机制与某些药物刺激的受体具有相似性，但属于高度健康、自适应的低水平调节），带来更加敏锐的思维状态与更强的自信心。 对于运动时间的最佳选择，早晨第一项活动就去锻炼往往能发挥最大的全天杠杆效益。一方面，早起完成锻炼能让一整天的心态和大脑工作状态受益；另一方面，若将锻炼推迟到一天结束时，生活琐事与推脱借口往往会干扰计划的执行。在寒冷、漆黑的清晨克服惰性起床的真正动力，正是预想到“如果今天不去跑步，接下来一整天会状态不佳”的鲜明对比。 ### [26:30](https://www.youtube.com/watch?v=WLWbFVKFffM&t=1590s) 零基础运动者的公共卫生红利与边际递减效应 针对完全没有运动习惯、正处于“零运动”状态的人群，无需被各种关于“运动量门槛”的复杂指南所吓退。科学数据显示，从公共卫生的角度来看，健康回报最巨大的一跃并非发生在马拉松跑者或高强度健身爱好者身上，而是发生在那些从几乎完全静止走向轻量活动的人群中。 运动带来的益处与边际效应表现出清晰的规律： - **最大增益区间**：从零起点每天增加 1,000 步，逐步提升到每天 2,000、3,000 或 4,000 步。这个跨越对心血管健康与大脑功能改善的公共卫生价值最大。 - **边际收益递减**：当个人的运动量已经达到很高水平时，继续追加运动量所带来的边际生理与认知增益会逐步收窄。 - 对于初学者而言，每天达成 4,000 至 5,000 步的活动量，就能为心血管系统与大脑健康奠定极为扎实的防护屏障。 ### [27:46](https://www.youtube.com/watch?v=WLWbFVKFffM&t=1666s) 哈扎部落与进化视角：人类身体活动的演化基准 为了破解现代人究竟需要多少活动量才符合基因演化机制，学者们将目光投向了地球上最后的狩猎采集部落之一——生活在坦桑尼亚北部的哈扎人（Hadza）。相关实地田野调查始于 2009 年，其核心目的在于探究人类在狩猎采集生活方式下的生理指标、活动常态及其与健康老龄化之间的联系。 研究哈扎部落的演化人类学意义在于： - **活态的演化窗口**：哈扎人依然基本维持全职的狩猎采集生活方式，为科学家提供了直观观察人类“原始活动常态”的参照系。 - **生理与认知关联**：通过记录他们为生存所必须付出的身体活动总量，分析该活动负荷与心血管健康生物标志物、认知功能维持以及衰老模式之间的对应关系。 - 这一研究视角让现代医学得以重新评估：人类身体并不是为了久坐而设计的，观察狩猎采集者的真实日常，是解密符合人类进化生物学最佳运动量的重要线索。 ### [29:17](https://www.youtube.com/watch?v=WLWbFVKFffM&t=1757s) 步数指标与活动量：哈扎人与现代老人的悬殊差距 谈到狩猎采集部落的生活方式时，步数是一项极其直观且便于大众自我追踪的衡量指标。虽然科学上有更为精密复杂的方法来评估体力活动，但计步无疑是通俗易懂的黄金标尺。研究团队通过穿戴设备测得，坦桑尼亚哈扎（Hadza）族人平均每天要走 15,000 至 20,000 步。这并不意味着现代人必须每天走两万步才算理想，从公共卫生角度而言，运动带来的健康收益在更低的活动量阶段就已经显现——每天走 4,000 到 6,000 步就能看到显著的健康改善，随着步数进一步攀升，收益会出现边际递减效应。因此，原始部落的生活水平与现代城市人获得最佳健康效益之间的门槛存在差异。 令人震惊的差距体现在老年群体的活动能力上。尽管哈扎人的体力活动水平确实会随着年龄增长而有所下滑，但即便到了 70 多岁甚至 80 岁出头，哈扎老人的运动量仍将欧美现代人远远甩在身后。研究通常用中高强度体力活动（MVPA，即心率达到最大心率 50% 至 55% 以上的运动）的时长来衡量运动表现： - **哈扎老人**：每天仍保持 60 到 80 分钟的中高强度体力活动。 - **美国老人**：平均每天仅仅维持 2 到 4 分钟的同等强度活动。 这种落差反映在整个人口统计中：美国目前仅有 25% 的成年人能够达到公共卫生建议的基准线（即每周累计 150 分钟中高强度运动）。相比之下，哈扎人通常仅用两天就能完成这一周建议量，短短几天内就能累计超过 300 分钟的中高强度运动。 --- ### [31:59](https://www.youtube.com/watch?v=WLWbFVKFffM&t=1919s) 慢性病非衰老宿命：哈扎人与齐曼内人的心血管健康启示 心血管疾病长期稳居美国乃至英国等发达国家头号致死原因的宝座。然而，当研究人员审视哈扎族人时，却几乎找不到心血管疾病的病理迹象。虽然目前尚未直接统计哈扎人的心血管疾病死亡率，但对其生物标志物的监测结果极为优异：他们的胆固醇水平、甘油三酯水平和血压表现均极其良好，极少出现高血压等病症。 无独有偶，针对南美洲玻利维亚原住民齐曼内（Tsimane）部落的长期精细追踪也得出了惊人一致的结论。齐曼内人被深入研究了心血管死亡结局，医学界在其族群中几乎检测不到动脉硬化或心血管死亡病例，糖尿病和阿尔茨海默病等痴呆症更是罕见。现代人往往将心血管疾病、糖尿病与认知退化视为衰老过程中不可避免的自然代价，但原始部落的生理事实推翻了这一假设——衰老并不必然伴随衰竭与慢性病，这些疾患大多是现代生活方式的产物。在认知退化领域，约有 40% 的痴呆症发病风险完全可以通过调整生活方式进行预防和干预。 --- ### [34:16](https://www.youtube.com/watch?v=WLWbFVKFffM&t=2056s) 久坐的生理机制：“无负荷”如何损害心血管系统 在长期从事哈扎人野外研究的过程中，受访学者的生活哲学发生了深远改变。运动固然是他个人生活与科研工作的基石，但近些年他将极大的学术热情倾注到了“坐”（Sitting）这一行为上。坐并不是纯粹意义上运动的反面，而是一种占据人类全天时间远超任何体力活动的日常状态。 久坐的危险恰恰源于它的极度舒适。人体在坐下的一瞬间，椅子完全承托住了身体，彻底卸去了下肢骨骼与肌肉的所有负荷。正如受访者打趣的那样，每当他上台做关于久坐危害的公开演讲时，台下的听众就会开始不由自主地坐立难安、挪动身体，甚至有人直接溜到后排站着听讲。当下肢肌肉彻底“熄火休眠”时，一系列不利的生理级联反应随之发生： ```mermaid flowchart TD accTitle: 肌肉休眠与久坐代谢障碍机制 accDescr: 对比久坐肌肉静止与活动状态下甘油三酯代谢对血管健康的影响流程 subgraph INACTIVE["长时间靠椅久坐（无肌肉负荷）"] A["下肢大肌肉群完全卸载静止"] --> B["脂蛋白脂肪酶等代谢酶活性暴跌"] B --> C["血液中的甘油三酯无法分解为脂肪酸"] C --> D["过剩脂质与代谢燃料在血管壁淤积"] D --> E["诱发内皮损伤与心血管病变"] end subgraph ACTIVE["主动微活动 / 原始休息姿态"] F["蹲/跪/地面坐姿维持低水平肌肉紧张"] --> G["下肢肌纤维持续微量消耗能量"] G --> H["血脂与游离脂肪酸被持续代谢分解"] H --> I["维持健康的血管与代谢内环境"] end ``` 肌肉静止导致原本用于为肌肉收缩供能的生理通路被阻断——血液中的甘油三酯无法被充分水解为游离脂肪酸进行燃烧，这些未被利用的燃料便在血管内堆积，直接促成了动脉硬化及一系列心血管健康恶果。 --- ### [36:12](https://www.youtube.com/watch?v=WLWbFVKFffM&t=2172s) 主动休息与椅子的历史：哈扎人的“蹲跪”与现代社会的坐具陷阱 借助加速度计对哈扎人进行全天候监测后，研究团队发现了一个令人大跌眼镜的事实：哈扎人每天非活动、处于休息状态的总时长，与久坐不动的现代都市人几乎完全相同。人类学家原以为猎人每天都在不知疲倦地奔波，但事实上他们与现代人一样渴望并需要长时间的休整。 决定性区别在于**休息的姿态**： - **哈扎人的休息**：不用椅子，而是采用蹲姿（Squatting）、跪姿（Kneeling）或是坐在地面上。这些姿势并非彻底卸力，它们要求下肢核心肌群保持微弱而持续的收缩来稳定躯干，身体必须隔三差五调整重心。这种“主动休息姿态”让低水平的肌肉活动得以维系，人体在进化中正是以此模式适应休息的。 - **现代人的休息**：依赖现代工业设计的椅子，完全剥夺了肌肉活动的所有必要性。 从考古学来看，椅子是一项极其反常的近代发明。已知最早的椅子残骸距今大约仅有 5,000 年历史，而椅子的普罗大众化更是近代才发生的转变。纵观人类文明史，椅子不仅关乎人体工学，更是政治权力与经济地位的具象化载体——“在桌旁占有一席之地”（Take a seat at the table）象征地位，“王座”（Throne）象征至高无上的君权，坐在哪里从来都承载着森严的阶级与社交含义。如今，现代建筑与居住环境几乎完全围绕坐具展开，客厅摆放着沙发与茶几，几乎所有人走进房屋最先接触的就是坐具。现代人早已把椅子视作理所当然的存在，却未曾察觉自己正被其生理机制所吞噬。 然而，追求省力是刻在人类基因里的本能。受访学者分享了一个生动的野外花絮：当科研团队深入哈扎人居住地时，为了野外工作舒适也自带了折叠椅。令人啼笑皆非的是，哈扎人看到椅子后丝毫不觉得奇怪或抗拒，反而爆发了一场真实的“抢椅子”（Musical chairs）大战——只要哪位研究员刚站起身，立刻就会有哈扎人眼疾手快地钻过来坐下。哈扎人并不觉得现代人古怪，他们同样深爱靠在椅子上的极致轻松，两者的唯一差别仅仅在于现代人把整个世界都铺满了椅子，而原始自然界中并没有椅子的存在。 ### [38:58](https://www.youtube.com/watch?v=WLWbFVKFffM&t=2338s) 久坐的破解之道：“运动零食”与打破久坐 在哈扎部落（Hadza）野外采集归来后，经常会出现所有人都在抢椅子坐的有趣场景——外出劳作了一整天，每个人都理应得到充分的休息。针对现代职场环境，史蒂芬·巴特利特（Steven Bartlett）提出了现实疑问：现代人总不能全天都蹲着办公或录制播客，对于那些居家办公、日常长时间被困在办公椅上的人，是否存在可行且折中的改善方案？ 戴维·赖克伦（Dr. David Raichlen）指出，彻底戒除坐姿既不现实，全天站立办公（Standing Desk）也并非灵丹妙药。真正的核心症结在于“持续且不间断的久坐”，最有效的对策是将长时段的久坐切碎成较短的时间块。他幽默地分享了一个屡试不爽的日常小妙招：“多喝水，逼着自己必须频繁起身去洗手间”，这是一种天然且不可违抗的强制休息提醒。 此外，“运动零食”（Exercise Snacks）是近年来被广泛倡导的高效策略。无需换上专门的运动服，只需每隔30至45分钟起身一次，进行极其简短的身体激活： - 快速爬几层楼梯 - 就地做几个俯卧撑或深蹲 - 站起来舒展筋骨，让肌肉群重新开始工作与代谢 --- ### [40:29](https://www.youtube.com/watch?v=WLWbFVKFffM&t=2429s) 碎片化高强度运动（VILPA）与代谢改善的硬核证据 面对这种碎片化运动，很多人难免怀疑：区区两分钟的走动，对整体健康真能产生实质影响吗？戴维表示，流行病学和严谨的实验室对照试验都已经给出了极为肯定的答案。 ```mermaid flowchart TD accTitle: 久坐干预对心血管与代谢指标的改善路径 accDescr: 展示长时间连续久坐与引入高强度间歇碎片运动（VILPA）在身体指标上的对比结果 subgraph BAD["长时间持续久坐（如连续8小时）"] A1["胰岛素敏感度下降"] A2["甘油三酯水平上升"] A3["心血管疾病标志物异常"] end subgraph INTERVENTION["日常碎片化干预（运动零食 / VILPA）"] B1["每隔20-45分钟起身"] B2["爬楼梯 / 极快步频走动1-2分钟"] B3["达到无法唱歌或交谈的高强度区间"] end subgraph GOOD["生理与临床获益"] C1["显著平抑餐后胰岛素峰值"] C2["改善甘油三酯清除速度"] C3["全因死亡率与心血管风险明显下降"] end INTERVENTION --> GOOD ``` 从流行病学角度看，目前备受瞩目的研究领域被称为“偶发性高强度体力活动”（VILPA，Vigorous Intermittent Lifestyle Physical Activity）。这并非专门安排的健身锻炼，而是日常生活中无意识完成的短暂高强度动作，比如用极快的步速走上一两分钟，或者快步上楼梯。 - **强度判定标准**：如果在行走时已经快到“无法自如唱歌，甚至无法顺畅交谈”，这就意味着已经进入了高强度区间。 - **全因风险降低**：大量追踪数据显示，频繁进行这类超短时间爆发性活动的人群，即便平时没有固定的健身习惯，其全因死亡率和心血管疾病风险也明显更低。 - **实验室严格验证**：在严谨的随机对照试验（RCT）中，受试者在对照日连续静坐8小时，在干预日则每坐20分钟就起身在跑步机上慢走2分钟。仅仅是打碎静坐状态，受试者的胰岛素敏感度、甘油三酯代谢以及多项心血管疾病生物标志物就出现了肉眼可见的积极改善。 --- ### [42:17](https://www.youtube.com/watch?v=WLWbFVKFffM&t=2537s) 有氧运动与抗阻训练：大脑认知的演化视角 史蒂芬提到自己的日常健身偏向力量抗阻训练，极少做有氧，他好奇如果核心目标是提升大脑功能、改善记忆与认知，是否有必要强制自己增加有氧运动。戴维强调两者都很重要，但从演化生物学的维度来看，有氧运动具有不可替代的独特优势。 有氧运动最容易与“认知挑战”进行有机结合。在户外跑步或快走时，大脑不仅要维持肌肉收缩，还必须实时处理复杂的空间导航、路线规划与外界动态刺激。这种身体耐力与大脑认知计算的实时联动，在封闭环境中做纯器械推举时很难完全模拟。 谈及近十年风靡一时的各类“脑力训练游戏”（Brain Training Apps）和益智拼图软件，戴维客观分析了其价值： - 这类游戏在改善某些特定维度的认知功能上的确显示出了一些微弱证据。 - 但整个商业市场的宣传严重超前于科学实证，许多研究的质控水平并不够高，其效果远没有宣传的那样神奇。 - 戴维坦言，在对抗痴呆症的现实防御战中，“只要有哪怕一丝潜在证据表明其有用，我也愿意去尝试”，但它绝不能取代真实的身体运动与现实世界挑战。 --- ### [44:27](https://www.youtube.com/watch?v=WLWbFVKFffM&t=2667s) 构建“认知储备”：终身学习如何对抗大脑萎缩 维持大脑健康的核心基石在于终身学习与持续的认知挑战。戴维指出，虽然流行病学中关于受教育程度的研究经常受到家庭背景、社会经济地位等混杂变量的干扰，但“终身学习”本身在抵御大脑退化方面拥有无可争议的效力。 这一机制在神经科学中被称为“认知储备”（Cognitive Reserve）。随着自然衰老，大脑组织的萎缩（Atrophy）在某种程度上是不可避免的生理过程，但个体之间日常认知表现的差异，取决于年轻与中年时期建立起的储备厚度： - **储备的形式**：既包括物理上的脑容量（如更厚实的海马体体积），也包括神经元之间错综复杂的丰富突触连接。 - **缓冲机制**：如果你构建了强大的神经回路和组织冗余，即使步入老年后部分脑组织发生生理性衰退，这些衰退也不会突破临床阈值，日常的生活自理与思维敏捷度将完好如初。 - **破坏储备的元凶**：吸烟与过量饮酒会直接加速大脑萎缩并提高阿尔茨海默病的发病率。权威医学标准通常将“过量饮酒”定义为女性每天超过1杯标准饮品（1 Drink）、男性每天超过2杯标准饮品。长期超出这一饮酒量，会导致不可逆的大脑体积缩水。 --- ### [46:37](https://www.youtube.com/watch?v=WLWbFVKFffM&t=2797s) 睡眠与大脑排毒：U型风险曲线与隐藏的“并发症” 除了运动与智力活动，睡眠是决定大脑退行性病变命运的另一关键支柱。现代脑科学揭示，深度睡眠是大脑至关重要的“排污窗口”，脑脊液系统在这一阶段全力运转，清除白天新陈代谢堆积的各种有毒蛋白斑块（如与神经退行性疾病密切相关的淀粉样蛋白）。睡眠质量一旦长期低下，大脑的排毒机能便无法顺利完成，导致病理斑块悄然沉积。 然而，睡眠时长与大脑健康之间并非“越多越好”的线性关系，而是呈现出典型的“U型曲线”（U-shaped curve）： - **黄金区间**：每晚7至9小时的规律睡眠，对应着痴呆症与认知衰退风险的最低点。 - **两极风险**：睡眠严重不足（少于7小时）与睡眠过长（常年超过9小时甚至更长）都会显著提高患病风险。 戴维特别澄清了关于“过度睡眠”（Oversleeping）的数据混杂偏差：嗜睡本身可能并不是直接致病原因，而是其他潜伏病理状态的外在表征。在流行病学调查中，很多嗜睡者往往正处于抑郁状态，而抑郁症本身与神经退行性病变高度共生；此外，一天只有24小时，如果睡眠与久坐占用了过多的时间块，必然会无情地挤压白天原本属于体力活动和肢体运动的宝贵时长，进而从代谢层面间接重创大脑。 ### [048:22] 健康老龄化的三大支柱与人际连接的进化渊源 时间的本质是具有排他性的：一天只有 24 小时，多睡一个小时、做做家务或增加轻度体力活动，都意味着必须挤占其他事情的时间。主持人 Steven 由此切入人际关系：拥有伴侣或朋友，是否真能提升大脑认知能力、保持大脑体积？嘉宾指出，这很大程度上取决于关系的质量。如果身处一段充满矛盾、极具挑战的关系中，反而会带来负面结果。 在健康老龄化的研究中，核心支柱主要有三点：饮食（Diet）、体育锻炼（Physical activity）以及社会连接（Social connections）。在经历疫情后，全球正面临严重的“孤独流行病”（epidemic of loneliness），越来越多人习惯了独居与孤独，这对大脑健康构成了实质威胁。鉴于很难对长期孤独展开随机对照试验（RCT），流行病学观察数据提供了强有力的支持：拥有高质量社交圈、在需要时能找到倾诉对象的人，其大脑退化风险明显更低。从人类进化史来看，社交连接曾是生存的必要前提；在狩猎采集时代，个体无法保证每天都能猎获食物，唯有与彼此信任、愿意分享的群体生活在一起，才能活下去。因此，社交网络早已在生理和进化层面与人类的健康牢牢绑定。 ```mermaid flowchart TD accTitle: 健康老龄化的三大支柱及其对大脑的影响 accDescr: 展示饮食、运动和人际连接如何共同支撑健康老龄化，其中高质量社交通过进化机制促进大脑健康。 subgraph Pillars ["健康老龄化三大支柱"] D["均衡饮食 (Diet)"] PA["体育活动 (Physical Activity)"] SC["社会连接 (Social Connections)"] end subgraph SocialQuality ["人际连接质量"] SC --> HighQ["高质量关系：有倾诉与信任对象"] SC --> LowQ["低质量/冲突关系：增加心理与大脑负荷"] end subgraph EvolutionaryLink ["进化与生存根基"] HighQ --> Evo["狩猎采集时期的资源互助与分享"] Evo --> BrainHealth["改善认知功能与延缓脑衰老"] end ``` --- ### [050:54] 空气污染：运动益处的大脑“减震器” 谈及环境对大脑的影响，嘉宾直言近期关于空气污染的研究结果既令人惊讶又令人沮丧。无论是在骑行通勤时血液指标的急性变化，还是长期的流行病学随访，均表明生活在空气重污染地区的人群患阿尔茨海默病（Alzheimer's disease）及其他认知障碍症的风险显著升高。 更严峻的问题在于：运动时人的呼吸频率和通气量大幅增加，这意味着会吸入更多悬浮颗粒物和污染物。嘉宾团队的研究显示，即使是在中度污染的空气中运动，也会显著削弱体育锻炼本应给大脑结构和预防认知衰退带来的保护收益。嘉宾以自己生活的洛杉矶为例，那里的空气污染相当严重；而该团队基于英国生物样本库（UK Biobank）等较为温和的污染数据分析，也得出了相同结论：在污染较重的户外环境跑步（例如伦敦市中心或纽约市中心），虽然整体健康收益不至于直接变负，但大脑所能获取的神经获益却大打折扣。 - **污染吸入效应**：剧烈运动加速通气，导致微细颗粒物深入肺泡并诱发全身及外周血炎症。 - **环境抵消现象**：在中度至重度空气污染中运动，运动对大脑结构体积与认知保护的益处被显著削弱。 - **城市运动建议**：尽量避开交通主干道或空气质量指数较差的时段，寻找空气洁净的公园或绿地。 --- ### [053:13] 球拍类运动与寻找“属于你的运动” Steven 分享了自己两个月前的大脑扫描经历。医生在诊断他患有 ADHD 的同时，给他的改善处方中赫然写着“球拍类运动”（Racquet sports）以及高压氧舱等项目。医生表示，将高强度身体活动与复杂的认知挑战结合，可以刺激特定脑区生长。嘉宾对此非常认同，并提到在他每次演讲结束后，台下听众（尤其是高收入年长群体）最常提问的运动就是网球。 网球等球拍类运动兼具三大优势：不仅需要有氧耐力，还涵盖大量的即时战术思考与极快的反应速度；同时它本质上是双人或多人的社交运动，随着年龄增长，打双打既能维持互动，又不会让跑动负荷过重。而对于公众最常追问的“我到底必须做多少运动”这种带着被迫意味的提问，嘉宾表示这种思维方式令人无奈。他建议人们摒弃寻找“完美绝对运动”的执念：如果跑步机让你抓狂，你就绝对无法长期坚持；如果打网球能让你感到兴奋，哪怕它在理论上不是所谓的最优解，但只要能让你坚持一辈子，那就是对你最好的运动。 --- ### [055:52] 内源性大麻素系统：运动带来快乐与对抗抑郁的生物学机制 当被问及自身最自豪或最惊艳的研究时，嘉宾回顾了自己十多年前关于内源性大麻素系统（Endocannabinoid system）的研究。人体自身会生成类似大麻有效成分的化学物质，并激活大脑中相应的内源性大麻素受体。研究发现，运动会显著上调这一系统，这正是“跑步者高潮”（runner's high）和运动让人感到愉悦的核心生理机制之一。 更妙的是，嘉宾团队发现这项机制并非人类独有：狗在运动后同样会出现内源性大麻素信号的上调。作为爱犬人士，嘉宾深有感触地表示，如果狗狗一天没有出去散步奔跑，就会显得无精打采，这与人类在生理奖励机制上高度相通。这项发现不仅揭示了寻找能激发内在奖励的运动的重要性，还为缺乏运动或丧失运动能力的人群为何极易出现抑郁症状，提供了坚实的神经生物学解释。不过嘉宾也提醒道，这些让人感觉良好的生化奖励并不总是“即刻生效”的，往往需要一定的适应过程。 ### [57:45](https://www.youtube.com/watch?v=WLWbFVKFffM&t=3465s) 运动新手的门槛与内源性奖赏机制 对于长期缺乏运动的人而言，刚开始锻炼时往往存在一道难以跨越的生理门槛。当一个人突然起身去锻炼，身体的神经内分泌调节需要一定时间才能启动。更关键的问题在于运动强度的把控：缺乏运动基础的人往往缺乏对体感强度的感知，极易在初始阶段“用力过猛”，超出了适度的强度区间。这种过度透支非但无法带来全天神清气爽的轻度愉悦感，反而会让人倍感痛苦。 专家指出，初学者最需要建立的认知就是“坚持足够长的时间，先建立起基础体能”。只要身体适应了初期的生理刺激，那种美妙的奖赏感自然会如期而至。“奖赏终会到来，你只需要给它一点时间。”只要熬过最初的适应期，锻炼就会从纯粹的意志力对抗转变为一种具有正向神经反馈的自我犒赏。 --- ### [58:20](https://www.youtube.com/watch?v=WLWbFVKFffM&t=3500s) 久坐的认知危机：指数级上升的痴呆风险与行为干预 当被问及当前实验室最具颠覆性、尚未完全证实的假说时，研究者指出了两个重点攻坚方向：一是将认知挑战与身体运动相结合的干预手段，这项研究目前仍处于雏形阶段；另一个更紧迫的核心课题，则是久坐对大脑神经健康的侵蚀机制。在过去几十年中，尽管公共卫生领域不断呼吁运动的重要性，但全美依然仅有 25% 的成年人能够达到推荐的运动标准，另外 75% 的人群始终无法被运动说教所打动。既然动员人们去健身房极其艰难，那么关注每个人每天都在进行的行为——久坐，或许是扭转大脑健康下行趋势更高效的切入点。 研究团队刚刚完成的一项大型流行病学研究揭示了久坐时间与痴呆风险之间的残酷真相：这一关联并非线性平缓上升，而是呈现出陡峭的指数级增长。如果每天坐 10 小时（对比每天坐 9 小时），患痴呆症的风险会上升约 10%；但如果每天坐 12 小时，其痴呆风险相比每天坐 9 到 9.5 小时将暴增 60%。“一旦坐着的时间突破了大约 9 到 9.5 小时的临界点，你的患病风险就会以非线性的指数方式飙升。”从每天坐 12 小时缩短到 8 小时，其执行门槛远低于要求一个久坐不动的人去跑马拉松，这一低成本、易落地的行为干预有望从根本上延缓大脑衰老。 ```mermaid flowchart TD accTitle: 每日久坐时长与痴呆风险的非线性关系 accDescr: 图表展示了从安全久坐时间到高危久坐时间的痴呆风险跃升过程 subgraph SafeZone["基准安全区间"] A["每日久坐 <= 9~9.5 小时<br/>(神经退行基准风险)"] end subgraph ModerateZone["风险递增区间"] B["每日久坐 10 小时<br/>(痴呆风险增加约 10%)"] end subgraph DangerZone["高危指数爆发区间"] C["每日久坐 12 小时<br/>(痴呆风险剧增 60%)"] end A -->|"突破临界时间阈值"| B B -->|"非线性指数级恶化"| C ``` 现场随即展开了一番充满趣味的探讨。主持人半开玩笑地提出，是否应该研发一种带震动甚至能施加电击的“惩罚座椅”，或者将久坐监测功能植入他所参与投资的智能穿戴设备 Whoop 中。研究者对此表示认同，强调“行为追踪”本身就是一种极具力量的干预方式。很多时候，人们对自己在椅子上消耗的时间浑然不知，仅仅连续记录两周的久坐总时长，所带来的数字震撼就足以激发起人们起身活动的内在动力。 - **核心数据**：全美仅 25% 成年人达到常规体能锻炼标准，这一比例数十年未有显著改善。 - **久坐危险阈值**：每日坐姿时长达到 9 至 9.5 小时是风险转折点。 - **痴呆风险对比**：每日久坐 10 小时较 9 小时风险上升 10%；每日久坐 12 小时较 9~9.5 小时风险剧增 60%。 --- ### [01:01:45](https://www.youtube.com/watch?v=WLWbFVKFffM&t=3705s) 是否存在“健脑食物”？地中海饮食与长期队列研究 谈及市面上形形色色的“补脑神药”以及大家习惯补充的 Omega 脂肪酸，研究者明确表示并不存在立竿见影的“神奇药丸”。研究饮食对大脑寿命的影响具有极其严苛的客观限制：大脑的退行性病变是一个横跨数十年的漫长过程，科研人员绝不可能强行对受试者施加长达十年的封闭式饮食控制实验，因为几乎没有人能严格遵守。因此，目前最具说服力的高质量证据均来自长期的前瞻性观察队列研究——记录人们数十年的饮食日志，并持续跟踪其认知健康轨迹。 从现有的最佳科研证据来看，对大脑最友好的饮食结构在很大程度上契合了地中海饮食的核心要素。其核心逻辑并非依靠某种单一的超级食物，而是通过整体抗炎、抗氧化的膳食组合来协同改善心血管代谢与脑血管健康。 - **推荐多摄入**：植物性食物、豆类、全谷物。 - **严格控制/减少**：加工肉类、红肉、精制加工食品、添加糖。 - **保护机制**：保护脑血管内皮功能，改善外周胰岛素敏感性，降低神经系统慢性炎症水平。 --- ### [01:03:07](https://www.youtube.com/watch?v=WLWbFVKFffM&t=3787s) 最危险的运动误区：打破非全即无的“零到一”心理门槛 在被问及人们对身体认知最危险的误区是什么时，专家直言：那就是“误以为必须达到巨大的运动量才能获得健康收益”。这种认知偏差在人群中构筑了一道极具破坏性的心理壁垒。当一个平时完全不动的人看到各类健康指南推荐每天走 12,000 步，而自己打开手机发现只有 3,000 步时，高达 9,000 步的巨大鸿沟会直接击垮行动意愿；反之，如果告诉他“只要从 3,000 步增加到 5,000 步，大脑和身体就能获得巨大的实质性收益”，这种触手可及的目标反而能激发持续行动。 主持人深有感触地剖析了现代人普遍存在的“非全即无（All-or-Nothing）”心理陷阱：大家往往误以为“零到一”的蜕变必须是从零直接跨越到“每周去五天健身房”，这在潜意识中宛如攀登珠穆朗玛峰，随之而来的巨大心理不适感会迅速诱发拖延与彻底逃避；同时，微小的改变又常被视作微不足道、甚至令人尴尬的事情。例如，许多人认为特意下楼走去买午餐而不是在手机 App 上点外卖是毫无意义的微末小事，忙碌的一天中如果无法去健身房大汗淋漓地举铁，就会彻底自暴自弃。 研究者强调，这种微小的起步对于久坐人群而言是“真正能够改变人生轨迹的（life-changing）”。它不仅能避免新手因盲目上强度而导致的跟腱断裂等严重运动损伤，更能在大脑中植入“动起来感觉不错”的正向强化循环。即使是日常习惯大强度训练的人，在忙到不可开交的日子里，也可以采用“运动零食（Exercise Snacks）”策略——例如上楼睡觉前快跑冲上楼梯、进行一段极快节奏的竞走，或是做几组俯卧撑。任何打破静止状态的微量活动，都在为大脑神经元注入至关重要的保护性生理因子。 ### [01:06:50](https://www.youtube.com/watch?v=WLWbFVKFffM&t=4010s) 赞助商插播：日常便捷营养的选择 主持人谈到了听众长期以来向他提出的关于代餐品牌 Huel 的疑问，即在思考个人营养时，Huel 究竟适合处于生活中的什么位置、它是否是最健康的选择。主持人坦诚地表示，在理想世界中，自己最渴望的选择是能每天坐下来，亲自烹饪和准备所有膳食。然而由于现实生活的快节奏和频繁奔波，在接触 Huel 之前，他经常因为忙碌而做出糟糕的饮食决策——为了赶进度，营养摄入不得不向工作优先级让步，最终只能随手抓零食或吃外带垃圾食品度日。 Huel 带来的改变在于提供了一种便捷且相对健康的便携式方案，其中包含维持全面均衡饮食所需的诸多营养素，恰好填补了奔波途中的营养缺口。针对市面上多样化的产品，主持人推荐了瓶装即饮版（RTD, Ready-To-Drink），并提示听众可前往英国本土的各大超市如 Tesco、Boots、Sainsbury's 或在线商城尝试购买。 --- ### [01:07:50](https://www.youtube.com/watch?v=WLWbFVKFffM&t=4070s) 衰老与阿尔茨海默病：正常认知变化与痴呆症的光谱 主持人向嘉宾抛出了一个核心疑问：阿尔茨海默病是否存在于一个连续的光谱之上，而光谱的初级端是否仅仅是普通的大脑自然衰老和记忆减退？作为经常采访各界顶尖学者的主持人，他观察到一个有趣的现象：部分受访的长者头脑极其敏锐，其思维清晰度甚至远超年龄仅为其三四十个百分点的年轻人；而另一些年长亲友，则表现出记忆力减退、自我意识减弱，甚至会在一个小时的谈话中反复讲述同一个简短故事，丧失了表达自己的流畅度。这种退化究竟属于普通脑萎缩还是属于痴呆症光谱？ ```mermaid flowchart TD accTitle: 正常大脑衰老与阿尔茨海默病/痴呆症的区别 accDescr: 图表展示了从正常衰老中的可管理认知变化，到严重影响日常生活的痴呆症及病理进展型阿尔茨海默病的区别。 subgraph Normal["正常衰老 (Normal Aging)"] A["认知与执行功能轻微改变"] --> B["日常自主生活能力保持完整"] end subgraph Impairment["痴呆症 (Dementia)"] C["认知能力显著退化"] --> D["严重影响日常生活与行动能力"] end subgraph Disease["阿尔茨海默病 (Alzheimer's Disease)"] E["具备典型神经病理特征"] --> F["呈不可逆的进行性持续恶化 (Progressive)"] end B -.->|跨越界限| C D --> E ``` 嘉宾解释称，在大多数人身上，随着年龄增长出现一定程度的认知变化是正常的生理现象，但这种变化一般不会显著干扰日常生活，个体仍然可以自主掌控生活轨迹；执行功能（如规划能力）和记忆会出现一些不可避免的小变化，但绝非痴呆症那种颠覆性的损害。痴呆症的定义标准正是认知退化已经实质性地剥夺了人们继续独立从事日常活动的能力。而在各类痴呆症中，最为普遍的阿尔茨海默病拥有独特的神经病理特征，是一种不可逆的进行性（progressive）疾病；即便当前科学尚无法完全阻止大脑随年岁增长而发生退行性改变，但病理性痴呆与常规衰老依然存在性质上的界限。 --- ### [01:10:23](https://www.youtube.com/watch?v=WLWbFVKFffM&t=4223s) 伴侣离世、悲恸与未被察觉的抑郁症假象 主持人随后提出了一个在生活中屡见不鲜的现象：当一位老年人的配偶或伴侣去世后，未亡人往往会迅速陷入剧烈的认知衰退，死亡风险似乎也成倍增加。这背后的机制是否包含皮质醇波动、激素失调甚至大脑加速萎缩？ 嘉宾对此给出了肯定的深入剖析，指出丧亲所致的悲恸（grief）本身便与大脑结构及认知功能的一系列改变密切相关： - **抑郁症与伪装的认知损伤**：未被识别或未经治疗的抑郁症在表象上与痴呆症极度相似。当老人深陷抑郁状态时，注意力无法集中，与人沟通时无法保持在场专注。这种注意力丧失会导致信息根本未能被大脑有效编码，从而在后续表现为严重的“记忆缺陷”。 - **干预的黄金窗口**：当老人主观感觉思维和记忆出现滑坡时，首要排查和解决的应当是抑郁症状，因为抑郁症是可以通过医学方式干预的。无论采取药物治疗、心理咨询，还是引入效果显著的身体运动，都能在改善情绪的同时为大脑神经带来直接益处。 - **社交纽带的断裂与孤独**：失去伴侣意味着核心社交支持的坍塌。孤独感与社会联系缺失对大脑退化推波助澜，因此看护家中的长辈与社区老人、帮助他们维系稳固的社交连接，是延缓退化极为关键的可控因素。 --- ### [01:12:39](https://www.youtube.com/watch?v=WLWbFVKFffM&t=4359s) 播客传统提问：这项研究如何拯救并改变世界 针对上一位匿名嘉宾留下的终极提问——“你的研究工作能如何帮助这个世界？”，嘉宾给出了一个看似朴素却意义深远的回答："少坐多动"（sit less and move more）。大脑衰老与退行性病变从不是孤立的个人问题，它会深刻影响到身边的家庭、看护者乃至宏观经济运行： - **万亿美元的经济与医疗负担**：据测算，到 2050 年，仅美国一国每年在阿尔茨海默病上的支出就可能高达 1 万亿美元。 - **预防重于治疗的现实策略**：目前针对阿尔茨海默病的药物疗效依然有限，尽管新药物展现了一定曙光，但整体医学界短期内难以提供彻底逆转疾病的神药。最大且最有效的突破口唯有**预防与延缓发病**。 被问及对未来走向是否抱有希望时，嘉宾坦言态度复杂。令他感到乐观的是，当前科学传播正在转向“提倡迈出一小步”（small steps first）而非设定难以逾越的大目标，这有助于激励大众改变生活习惯；然而令人担忧的宏观数据依然在向不良方向演变：全球范围内，越来越多国家正在复制美英等国高久坐、少运动的现代生活方式，叠加全球人口老龄化浪潮，患病群体的绝对基数正在激增。嘉宾呼吁，唯有将全民行动聚焦于减少久坐、增加日常身体活动，才有可能在全球老龄化时代真正减轻社会与经济负担，守住人类的晚年福祉与尊严。 ### [01:15:34](https://www.youtube.com/watch?v=WLWbFVKFffM&t=4534s) 知识的力量：致谢科研对人类大脑与健康的深远贡献 主持人对整场对话表达了由衷的敬佩与感谢，将其形容为一场“极具启发性、鼓舞人心且最重要的是充满动力的对话”。他强调“知识就是力量”（knowledge is power），本场访谈所传递的科学见解为他自己以及所有听众注入了切实的行动力，促使大家去践行那些对认知结果及日常整体健康至关重要的行为习惯。 除了感谢嘉宾的倾囊相授，主持人还特别致敬了嘉宾所从事的开创性研究工作。他指出，学者们深耕科研或许源于内心纯粹的好奇心与热爱，但这项工作对全社会而言更是一项不可估量的巨大贡献。学者们花费海量的时间与心血进行严谨探索，再将这些成果转化为能够服务大众的通俗智慧，帮助人们在晚年依然保持健康、快乐与心智健全，从根本上维系了无数家庭的幸福完整。嘉宾也诚挚表达了受邀参与节目的喜悦与感谢。 - **行为驱动力**：科学认知的普及不仅解答了大脑如何运作的机理，更直接为日常锻炼、生活方式的改变提供了行为动力。 - **科研的社会价值**：将复杂的演化生物学与神经科学研究推向公众，最终目的是提升全民晚年的认知生命质量，让长辈安享健康晚年。 --- ### [01:16:25](https://www.youtube.com/watch?v=WLWbFVKFffM&t=4585s) 避开一月节食营销陷阱：个性化营养与长期生活习惯 对话结束后，主持人带来了一则健康提醒与赞助分享。每年一月份正值各大商业减脂、节食公司大肆营销的狂欢月，社交媒体和各类渠道充斥着铺天盖地的营销术语和极端节食概念。主持人呼吁大众切勿盲目陷入所谓的短期流行风潮（fads），在关乎自身健康的关键问题上，必须倾听真正科学家的专业意见。 主持人以自身投资并由其赞助的健康科技公司 Zoe 为例，说明了科学营养的核心逻辑：健康的饮食管理绝非单纯地克扣热量或严苛限制某种食物，而是通过“个性化营养”（personalized nutrition）了解适合自身身体的饮食模式，从而建立起能够受用一生的可持续日常习惯。通过量身定制的科学搭配，身体不仅能在短期内迅速感受到精力与状态的提升，更能为长远的机体健康奠定基石。最后，主持人向听众提供了专属优惠码，并推荐了与本期内容深度呼应的往期精彩对谈节目。 - **拒绝极端口号与噱头**：每年年初的节食热潮往往伴随大量伪科学营销，盲目节食和过度限制摄入往往难以持久且有害健康。 - **个性化营养的核心**：每个人对不同食物的代谢反应截然不同，依靠科学检测与专家指导建立的日常健康习惯，才是长期维持精力与大脑活力的关键。 ## Notable quotes > [00:00](https://www.youtube.com/watch?v=WLWbFVKFffM&t=0s) 每天坐 10 小时相比每天坐 9 小时，罹患失智症的风险会上升约 10%；而一旦久坐时间攀升至每天 12 小时，这一患病风险将暴增约 60%。 — David Raichlen > [02:10](https://www.youtube.com/watch?v=WLWbFVKFffM&t=130s) 成年后的大脑依然具有生成新生神经元（即神经发生，neurogenesis）的能力，尤其是在主管记忆的核心中枢——海马体（hippocampus）中。 — David Raichlen > [10:10](https://www.youtube.com/watch?v=WLWbFVKFffM&t=610s) 肌肉在收缩运动时会产生并分泌一类名为肌细胞因子（myokines）的蛋白质。这些蛋白质通过血液循环穿透屏障到达大脑，与神经元发生相互作用，进而上调神经滋养因子的表达。 — David Raichlen > [12:54](https://www.youtube.com/watch?v=WLWbFVKFffM&t=774s) 人体本质上是一个极度高效的“能量最小化机器”（energy minimizers）。 — David Raichlen > [26:30](https://www.youtube.com/watch?v=WLWbFVKFffM&t=1590s) 健康回报最巨大的一跃并非发生在马拉松跑者或高强度健身爱好者身上，而是发生在那些从几乎完全静止走向轻量活动的人群中。 — David Raichlen > [38:58](https://www.youtube.com/watch?v=WLWbFVKFffM&t=2338s) 多喝水，逼着自己必须频繁起身去洗手间。 — David Raichlen > [48:22](https://www.youtube.com/watch?v=WLWbFVKFffM&t=2902s) 在健康老龄化的研究中，核心支柱主要有三点：饮食（Diet）、体育锻炼（Physical activity）以及社会连接（Social connections）。 — David Raichlen > [57:45](https://www.youtube.com/watch?v=WLWbFVKFffM&t=3465s) 奖赏终会到来，你只需要给它一点时间。 — David Raichlen > [58:20](https://www.youtube.com/watch?v=WLWbFVKFffM&t=3500s) 一旦坐着的时间突破了大约 9 到 9.5 小时的临界点，你的患病风险就会以非线性的指数方式飙升。 — David Raichlen > [01:03:07](https://www.youtube.com/watch?v=WLWbFVKFffM&t=3787s) 误以为必须达到巨大的运动量才能获得健康收益。 — David Raichlen > [01:12:39](https://www.youtube.com/watch?v=WLWbFVKFffM&t=4359s) 少坐多动 (sit less and move more)。 — David Raichlen > [01:15:34](https://www.youtube.com/watch?v=WLWbFVKFffM&t=4534s) 知识就是力量 (knowledge is power)。 — Steven Bartlett ## Mentioned Steven Bartlett, David Raichlen, Daniel E. Lieberman, Gerd Kempermann, Jack, USC (University of Southern California), UK Biobank, The Diary Of A CEO, The 33 Laws Of Business & Life, Whoop, Huel, ZOE, Tesco, Boots, Sainsbury's, Hadza, Tsimane ## Video description If you enjoy hearing about the link between human evolution and exercise, I recommend you check out my first conversation with Dr Daniel E. Lieberman, which you can find here: https://www.youtube.com/watch?v=ujRwf1HdNjk 00:00 Intro 01:59 My Work: How Lifestyle & Exercise Affects the Brain 03:07 You Can Change an Ageing Brain 05:22 What Is a Neuron? 05:36 What Is the Hippocampus 07:28 The Link Between Exercise and Brain 09:06 What Happens to Our Brain When We Don't Exercise 12:54 People Aren't Meeting the Guidelines for Good Health 15:25 What Activities Are Good for Our Brain? 17:35 Orienteering Can Train the Brain 18:47 How the Different Types of Exercise Increase Neuroplasticity 22:39 Impact of Exercising in Greener Spaces Than Urban 24:06 Better Cognition Exercising Before a Task 25:41 The Optimal Time of the Day to Exercise 27:46 The Hadza: Researching Hunter-Gatherer Tribes & the Findings 28:56 What Is the Optimal Exercising Time? 31:59 Cardiovascular Illnesses in Hadza Tribe 35:07 What's the Issue with Sitting? 40:29 The Power of Daily Small Amounts of Exercise 42:17 How to Improve Memory 46:08 Top Factors That Fuel Cognitive Problems 48:38 Link Between Human Connection & Brain Impact 50:54 Pollution Impact on the Brain 53:13 Racquet Sports for Brain Health 54:41 How Much Activity Do I Have to Do? 55:52 Endocannabinoid Receptors and Exercise Rewards 57:24 Mental Health Issues Linked to Lack of Exercise 01:01:45 Brain Foods 01:03:07 Reaching Optimal Living 01:07:50 What Causes Alzheimer's? 01:12:39 Last Guest Question Follow David: Twitter - https://bit.ly/483oZIF My new book! 'The 33 Laws Of Business & Life' is out now - https://smarturl.it/DOACbook Follow me: https://beacons.ai/diaryofaceo Sponsors: Huel: https://g2ul0.app.link/G4RjcdKNKsb ZOE: http://joinzoe.com with an exclusive code CEO10 for 10% off [Source](https://www.youtube.com/watch?v=WLWbFVKFffM)

[0:00] David Raichlen: 每天坐 10 小时相比每天坐 9 小时，罹患失智症的风险会上升约 10%；而一旦久坐时间攀升至每天 12 小时，这一患病风险将暴增约 60%。 [2:10] David Raichlen: 成年后的大脑依然具有生成新生神经元（即神经发生，neurogenesis）的能力，尤其是在主管记忆的核心中枢——海马体（hippocampus）中。 [10:10] David Raichlen: 肌肉在收缩运动时会产生并分泌一类名为肌细胞因子（myokines）的蛋白质。这些蛋白质通过血液循环穿透屏障到达大脑，与神经元发生相互作用，进而上调神经滋养因子的表达。 [12:54] David Raichlen: 人体本质上是一个极度高效的“能量最小化机器”（energy minimizers）。 [26:30] David Raichlen: 健康回报最巨大的一跃并非发生在马拉松跑者或高强度健身爱好者身上，而是发生在那些从几乎完全静止走向轻量活动的人群中。 [38:58] David Raichlen: 多喝水，逼着自己必须频繁起身去洗手间。 [48:22] David Raichlen: 在健康老龄化的研究中，核心支柱主要有三点：饮食（Diet）、体育锻炼（Physical activity）以及社会连接（Social connections）。 [57:45] David Raichlen: 奖赏终会到来，你只需要给它一点时间。 [58:20] David Raichlen: 一旦坐着的时间突破了大约 9 到 9.5 小时的临界点，你的患病风险就会以非线性的指数方式飙升。 [63:07] David Raichlen: 误以为必须达到巨大的运动量才能获得健康收益。 [72:39] David Raichlen: 少坐多动 (sit less and move more)。 [75:34] Steven Bartlett: 知识就是力量 (knowledge is power)。

[5:22] David Raichlen: A neuron is sort of the main cell in your brain that's responsible for communication and transmission of information across brain regions. [7:28] David Raichlen: Our physiology evolved in this context of large levels of physical activity on a consistent basis... that's sort of the normal condition for humans. And anything else... is actually the condition that is quite different from the way that our physiology functions best. [18:47] David Raichlen: The combined environment doubled the growth and survival of new neurons compared to either wheel running alone or cage enrichment alone. [24:06] David Raichlen: You've activated reward centers in your brain that have increased your arousal... when we feel good, we feel more confident. We're not as sort of stuck in our heads... we're more present. [27:46] David Raichlen: The Hadza provide a window into what a hunting and gathering lifestyle looks like... how much physical activity does it take to be a hunter-gatherer, and how does that relate to biomarkers of cardiovascular health or cognition? [35:07] David Raichlen: A chair is a fairly new invention... chairs are these weird objects that are not only ergonomic and made for our comfort, but they also over history have had implications for economic status and power. [39:15] David Raichlen: If you're walking and you can't sing at the same time or you can't talk at the same time, that's now you're getting into kind of a vigorous intensity. [54:41] David Raichlen: Don't look for the perfect [72:39] David Raichlen: If you sit less and you move more, you will not only help yourself, but you will also help the general population.

[0:00] If you sit for 10 hours a day compared [0:02] to 9 hours a day, it's about a 10% [0:04] increased risk of dementia. If you sit [0:06] for 12 hours a day, it's about a 60% [0:09] increased risk of dementia. 60%? Yes. [0:11] So, it's a problem that we have to deal [0:13] with. David Raichlen, Professor of human [0:16] evolutionary biology, exercise [0:18] physiology, and neuroscience. [0:20] At the University of Southern [0:21] California, we are dealing with brain [0:23] health problems that are only going to [0:25] increase as our population ages. And [0:28] healthy aging is linked to three major [0:30] diet, physical activity, and social [0:32] connections. For example, people who [0:34] have stronger social connections tend to [0:36] have better brain outcomes than people [0:38] who don't. Does excessive alcohol use [0:40] shrink the brain? Yes. Over one drink [0:43] per day is associated with negative [0:44] health outcomes. Sleep is the other one. [0:46] That's a big factor in cognitive [0:48] decline, right? [0:49] It is. Less sleep and lots of sleep are [0:51] both associated with higher risk. Is [0:53] there an optimal amount of exercise? [0:55] Physical activity guidelines are 150 [0:57] minutes per week, but only 25% of adults [1:00] in the US meet those guidelines with [1:02] older adults doing two to four minutes [1:04] per day. Two to four? But there are [1:06] these small activities that provide big [1:08] benefits, that generate new neurons, and [1:11] those neurons get integrated into key [1:13] parts of the brain. Number one is [1:16] Remote work is dangerous. [1:17] It's unnatural for the human body. I'm [1:19] concerned about physical health. What's [1:21] the practical advice to people that work [1:23] at home that is realistic for us? If you [1:24] combine [1:26] with [1:27] it will literally change your life. [1:30] I think this is fascinating. I looked at [1:33] the back end of our YouTube channel, and [1:35] it says that since this channel started, [1:37] 69.9% [1:39] of you that watch it frequently haven't [1:41] yet hit the subscribe button. So, I have [1:43] a favor to ask you. If you've ever [1:45] watched this channel and enjoyed the [1:46] content, if you're enjoying this episode [1:47] right now, please can I ask a small [1:49] favor? Please hit the subscribe button. [1:50] Helps this channel more than I can [1:52] explain, and I promise if you do that to [1:54] return the favor, we will make the show [1:57] better and better and better and better [2:00] and better. That's a promise I'm willing [2:01] to make you if you hit the subscribe [2:02] button. Do we have a deal? [2:04] [Music] [2:10] David, if you had to summarize the [2:14] essence of what your work shines a light [2:16] on, and what it intends to help us [2:18] understand as human beings, how would [2:19] you summarize that? What my work has [2:22] been focused on is understanding how and [2:26] why physical activity, especially and [2:30] lifestyle behaviors in general, can [2:31] impact health and most specifically [2:34] impact the health of our brains. [2:37] And I think that you know, we are [2:40] dealing with [2:43] brain health problems that are only [2:45] going to increase as our population [2:47] ages. [2:48] So, we have we have 6 million people in [2:51] the US today that are diagnosed with [2:54] Alzheimer's disease or other related [2:55] dementias. That's projected to grow to [2:58] around 13 million people over the next [3:00] 25 years or so. [3:03] It's we're projected to have 150 million [3:05] people diagnosed with dementia worldwide [3:07] over the next 30 years or so. So, it's a [3:10] problem that we have to deal with, and I [3:12] my work has been focused on ways that we [3:15] can prevent these diseases that are [3:17] associated with aging. Why does the [3:19] brain matter? And I say this in part [3:22] because I think for most of my life I [3:23] just assumed [3:25] you know, I understand muscles. I can go [3:26] to the gym and work on my muscles, but [3:28] the brain I just thought is this like [3:29] piece of tofu in between my skull that I [3:32] have very little control over. [3:34] Yeah. I mean, I think that is that was [3:36] the prevailing view for a long time [3:37] that, you know, we grow our brains as [3:40] children and during adolescence, and by [3:42] the time you're in your 20s, your brain [3:45] has done all the growing it's going to [3:46] do, and now it's just this progressive [3:48] shrinking over the rest of your life. [3:50] And, you know, over the last few [3:51] decades, we've realized that's not true, [3:53] actually, that you can [3:55] generate new neurons, especially in key [3:58] areas of the brain like the hippocampus [4:01] that's associated with memory, and that [4:04] that growth of new neurons may be the [4:07] key to preventing or staving off these [4:10] neurodegenerative diseases that have [4:12] this big impact on aging brain. And so, [4:16] you know, if we can find ways to do [4:19] that, and and what I study is [4:21] kind of doing that through physical [4:23] activity and exercise, [4:25] then we might be able to prevent some of [4:27] the cognitive decline people experience [4:29] with aging, maybe even stave off or [4:31] prevent the development of Alzheimer's [4:33] disease or other dementias. What [4:35] evidence have scientists got that we can [4:37] actually grow [4:39] our brain? Well, that's a great [4:41] question. [4:42] The evidence in humans is a little [4:44] trickier, so I can talk more about the [4:46] evidence from animal models because with [4:49] animal models you can actually look [4:51] inside the brain and see what's [4:52] happening after say an exercise [4:54] intervention. So, there have now been [4:56] many, many studies, especially in mice [4:58] and rats, where researchers have shown [5:01] that if you give them access to running [5:03] wheels, or if you have them run on a [5:05] treadmill, that you actually generate [5:08] new neurons, and those neurons survive [5:10] and get integrated into key parts of the [5:13] brain, and we focus a lot on the [5:14] hippocampus because it's so important to [5:18] memory, [5:19] which is a which is a major aspect of [5:21] being human is being able to remember [5:22] things. And [5:25] researchers have shown very clearly that [5:27] exercise and physical activity in these [5:29] rodent models leads to the birth and [5:31] survival of new neurons. [5:34] What is a neuron? A neuron is the main [5:37] brain cell. [5:39] So, a neuron is sort of the main cell in [5:41] your brain that's responsible for [5:44] communication and transmission of [5:45] information across brain regions. And [5:48] where you said this hippocampus thing, [5:50] which is where I know you referenced [5:51] that it's this sort of center point for [5:52] memory. [5:53] Yeah. [5:54] Where is that located in the head? So, [5:55] the hippocampus is sort is in the [5:56] temporal deep in the temporal lobe of [5:58] the brain. It looks like a seahorse, if [6:01] you know if it's kind of this curved [6:03] curved object in the brain that plays a [6:06] big role in different aspects of memory. [6:09] So, it plays a big role especially in [6:11] working memory, which is [6:13] keeping things in your memory over the [6:15] short term that you may need to recall [6:17] quickly. And it also plays a big role in [6:20] the formation of memories of events [6:23] that happen in your life, and also in [6:25] spatial navigation, which is [6:27] an important part of moving around in [6:29] the world. So, it's a really key part of [6:31] the brain, [6:33] and it's also one of the parts of the [6:34] brain that is most affected by [6:36] neurodegenerative diseases like [6:38] Alzheimer's disease. So, it is a part of [6:40] the brain that deteriorates in these [6:42] diseases, leading to memory deficits [6:45] that have a [6:46] big effect on your daily life. Is that [6:49] the only part of the brain that we're [6:51] able to sort of regenerate? Or is it [6:53] kind of the rest of the You know, I'm [6:54] thinking about these rats and these [6:56] mice. If we put them under a brain scan, [6:58] would we see the the mass of the brain [7:00] increasing? [7:02] It's a good question. And is it just [7:03] that little seahorse hippocampus part, [7:05] or is it the whole brain growing? So, in [7:08] in rodent models where [7:10] where researchers have done sort of this [7:12] detailed work, the hippocampus is where [7:15] mainly where new neurons have been found [7:18] associated with exercise. In human [7:20] studies, brain effects have been more [7:22] widespread, so you do see volumetric [7:24] changes in the hippocampus, but you also [7:27] see volumetric changes or preservation [7:29] of brain volume in frontal lobes, which [7:32] are associated with executive cognitive [7:35] function, so things like planning and [7:37] decision-making. [7:39] Um Where do we need to begin to [7:40] understand [7:42] this relationship that humans have [7:43] between [7:44] exercise and [7:47] their brains? There's got to be a point [7:49] in history where exercise became [7:52] I guess pro-survival in a way, where it [7:54] became sort of imperative for us as a [7:56] human species to do in order to [7:58] preserve and extend our cognitive [8:01] capacity, I guess. Yeah, I mean, all [8:03] animals generally have to move to [8:05] survive, right? They have to move to [8:07] find food in some way, but at some point [8:10] during human history, [8:13] our our pattern of movement shifted [8:14] pretty dramatically, and we think that [8:16] was around 2 million years ago. And at [8:18] that point we shifted from a more [8:20] ape-like lifestyle to a hunting and [8:23] gathering lifestyle, where our travel [8:27] distances increased drastically, so we [8:29] were moving over, you know, 20 km [8:32] sometimes per day, [8:34] sometimes longer, [8:36] and our intensity of movement probably [8:38] shifted a bit to higher intensities. And [8:41] so, the need to be physically active [8:44] changed. And if we think about the way [8:46] that our physiology evolved, our [8:48] physiology evolved in this context of [8:52] large levels of physical activity on a [8:54] consistent basis. And so, I like to [8:56] think of that as sort of the normal [9:00] condition for humans. And anything else, [9:03] so as we kind of progress into modern [9:05] times, and and many people have dropped [9:07] their activity, [9:09] that's actually the condition that is [9:11] quite different from the way that our [9:12] physiology functions best and and from [9:15] the way that our physiology evolved. [9:17] Does this mean that if I don't do [9:20] physical activity, my brain will shrink? [9:23] That's a good question. I mean, on a on [9:25] a broad public health scale, yes, you [9:28] know, low levels of physical activity or [9:30] inactivity is associated with poor brain [9:33] health, smaller volumes of key brain [9:36] structures, so smaller hippocampal [9:38] volumes, for example, and worse [9:40] cognition overall, and greater risk of [9:43] dementia and Alzheimer's disease. On a [9:45] personal level, it's hard to say [9:47] specifically, right? Because there's so [9:49] many factors that go into your risk of [9:52] of dealing with these conditions, but I [9:55] can say that the best way for any [9:57] individual to reduce their risk of [10:00] cognitive decline is to be physically [10:02] active. What exactly is going on in my [10:04] brain then when I'm physically active [10:06] that's causing my brain to be protected [10:08] insulated from things like Alzheimer's [10:10] and dementia and in some areas of the [10:13] brain to actually grow. What is what is [10:15] actually happening inside? [10:16] A lot of fun things. Um so I mean one of [10:19] the things that happens when we exercise [10:21] is we increase blood flow to the brain [10:23] and that helps bring nutrients and and [10:26] keep our neurons functioning properly. [10:28] But another thing that happens is that [10:30] your muscles actually generate proteins [10:32] called myokines and those travel to the [10:35] brain and they uh interact with neurons [10:39] in ways that upregulate neurotrophin. So [10:42] there's this great neurotrophin called [10:43] brain-derived neurotrophic factor BDNF [10:46] and BDNF acts kind of like a fertilizer [10:48] for brain cells or for new neurons. So [10:51] BDNF when it's up regulated with [10:53] exercise um helps both the birth of new [10:56] neurons and it helps them to survive and [10:58] integrate into the processes that [11:01] they're that they're meant to work for. [11:03] This is probably a stupid question but [11:04] I'm just wondering why the brain just [11:05] doesn't do that anyway. I know, right? [11:07] Wouldn't it be nice? Wouldn't it be nice [11:09] if it I didn't have to exercise for the [11:11] brain to restore itself in such a way [11:13] and to expand? It It would be nice in [11:15] some ways but that's just that's not [11:17] really the way that our physiology [11:19] works, right? So you know as I was kind [11:21] as I was saying if you think of the sort [11:23] of natural condition of humans as being [11:27] physically active because that's what we [11:28] had to do to find food and survive then [11:31] our physiology is adapted to that [11:35] condition and over the course of 2 [11:37] million years we never had to adapt to [11:40] low levels of physical activity because [11:41] it just wasn't a part of being human and [11:44] so it's only been in the last you know [11:48] few hundred years that we've seen this [11:50] rapid decline in activity and that's [11:53] just not enough time to see that sort of [11:55] adaptation occur. What happened a couple [11:58] of hundred years ago that caused this [12:00] decline in physical activity? Was there [12:02] like a certain invention or something? [12:03] Was there a change in cultural [12:04] understanding? [12:06] I mean I think things start with the [12:07] Industrial Revolution. [12:08] Okay. [12:08] As we as we mechanize and we find ways [12:11] to um to reduce [12:14] um our the the need to uh be physically [12:17] active to gain access to food to survive [12:21] um and then as as we move on you know in [12:23] the last 50 60 70 years we start to see [12:27] a lot more office jobs, right? We start [12:30] to see changes in our work life that [12:32] reduce activity patterns throughout the [12:34] day. Cars, I guess. [12:36] Cars, so in terms of commuting, leisure [12:39] time. What do we What do most people do [12:41] during their leisure time? The couch is [12:43] really comfortable. Our screens are [12:46] really enticing TV screens but now phone [12:49] and computer and all these things and so [12:52] we ended we end up sitting a lot. Do you [12:54] have the stats on the increase in [12:57] sedentary behavior that is basically [12:59] people being still? It's hard in terms [13:02] of increase because we we haven't [13:05] measured time spent sitting for very [13:07] long. That's really been a pretty recent [13:09] part of research. Uh but we do know that [13:11] today people are sitting for on average [13:15] 9 to 10 hours per day and that level of [13:18] sitting [13:20] um is also linked with really low levels [13:22] of then being physically active. So um [13:25] we can think about you know how many of [13:27] us are actually [13:29] active enough to meet the kinds of [13:31] guidelines that that are prescribed for [13:33] health um and we're talking about 25% of [13:36] US adults actually meeting those [13:38] guidelines and that number hasn't [13:39] changed in in 20 years or so even with [13:42] all the messaging physical activity is [13:44] good for you. You need to be more [13:46] active. You need to exercise. [13:48] You know people just don't do it. I [13:49] guess this the very heart of this is [13:51] this idea when we're talking about the [13:53] brain not just taking care of itself [13:55] without physical activity is this notion [13:58] that all parts of our body and all parts [14:00] of our being [14:02] are created in response pretty much or [14:04] at least develop in response to an [14:05] external stimuli of some sort. So like [14:07] me going to the gym the example I gave [14:09] earlier if I pick up the weight then the [14:10] muscle grows and whenever I try and [14:13] implement a very sudden behavioral [14:15] change like when I [14:16] suddenly started training football four [14:19] times a week my my muscles basically [14:21] exploded in my feet because they just [14:23] weren't strong enough to deal with that [14:24] demand and I guess the same applies to [14:27] the brain that if we don't use it [14:30] we we lose it basically. Yeah, I mean [14:32] our our bodies are uh fantastic at [14:36] tuning [14:37] what we put energy into to maintain to [14:40] the kinds of activities that we're that [14:42] we're engaged in, right? And so you know [14:44] I like to think of our bodies as great [14:46] energy minimizers in some ways that you [14:49] know if you're not using muscles those [14:51] muscles will get smaller because it [14:53] takes energy to maintain that tissue. If [14:55] you're not [14:57] you know creating the need for your [14:58] heart to pump blood across your body by [15:00] exercising you'll atrophy some of that [15:03] tissue. You'll you'll reduce blood [15:05] vessels. Your heart will become less [15:06] efficient because [15:08] you've signaled to your body that you [15:10] don't need that energy to put be put [15:12] into that tissue maintenance. The same [15:14] it seems holds true for the brain that [15:16] if you're not active um in some way then [15:20] you're kind of signaling that you don't [15:21] need some of that uh energy to be put [15:23] into that tissue. [15:24] Is all activity the same? So if I'm [15:26] doing strength training [15:29] is that as beneficial for my brain as [15:30] potentially going for a run outdoors? [15:33] That's a great question and um you know [15:35] we [15:37] there is not a ton of very clear work [15:39] that's compared directly different types [15:42] of activity in ways that we were where I [15:44] could tell you for sure this is the best [15:46] one, right? There are data that suggest [15:49] that resistance training is beneficial [15:51] to the brain. There's more work on [15:53] endurance activity and I actually think [15:55] that's probably because it's easier to [15:57] do rodent work on endurance activity [15:59] than resistance and so trying to [16:01] translate across those models is a [16:02] little bit easier. Both forms of [16:04] exercise have benefits. They may be [16:06] through different pathways. Um there may [16:09] be different biological mechanisms that [16:11] are underlying those benefits. I've kind [16:13] of seen some cool work coming out lately [16:16] that has tried to look at uh for example [16:18] different types of endurance exercise. [16:20] So there's a great study that came out. [16:22] Are you familiar with orienteering? It's [16:24] a sport where you're given like a map [16:27] and a compass and you have to uh find [16:30] your way across a route as fast as [16:32] possible. So it kind of mixes endurance [16:34] activity with spatial navigation and and [16:38] uh moving around your environment and [16:39] figuring out where you are. Typically [16:41] done outside, right? [16:42] Oh yeah, always done outside. Typically [16:44] done on natural like uh trails and [16:46] things but people do do it in cities as [16:48] well. [16:48] Okay. So like and this is over the miles [16:50] and courses. [16:51] this would be like a like a trail run [16:53] kind of or something like that. And [16:55] there was a great study that just came [16:56] out looking at um it was a randomized [16:59] control trial so they actually [17:00] randomized people into either an [17:02] orienteering group or a hiking group or [17:04] a control group and over a couple months [17:07] they found that the orienteering group [17:09] actually had uh better performance on uh [17:13] cognitive tests like memory tests and [17:14] executive function tests than even the [17:17] hiking group. Both of those groups did [17:19] better than the control group but there [17:20] was actually this extra boost if they if [17:22] for the people who were in the [17:24] orienteering group. So we're starting to [17:26] see that maybe some different activities [17:29] could potentially enhance the effects of [17:31] exercise on the brain. What's the [17:33] conclusion then? What does that study [17:36] hint at in terms of cuz hiking you're [17:38] out in nature you're navigating your way [17:39] up a hill or something. Orienteering [17:42] that it's it's almost like solving a [17:44] puzzle, right? Because you've got a map [17:45] and a compass. Yeah, I mean I think it [17:48] it fits into an evolutionary model at [17:50] least in my mind [17:52] um where the purpose of being physically [17:55] active is to move around a habitat to [17:58] find things. Find food, find water, find [18:01] firewood um and so physical activity in [18:04] a in this sort of ecologically relevant [18:06] world is a combination of cognitive [18:10] challenges and physical challenges. So I [18:13] think that when you combine them in the [18:15] way that perhaps orienteering does or [18:17] maybe some other sports you might [18:19] actually get a bigger boost for your [18:21] buck, a bigger bang for your buck um in [18:24] terms of the brain benefits. And that I [18:26] think is rooted in our evolutionary [18:28] history. Like I said I think that being [18:30] active in an evolutionary sense always [18:33] comes with sort of a cognitive [18:34] challenge. Nobody's ever just going out [18:36] for a workout. There's no reason to. If [18:39] you're not If you don't need to find [18:40] something you're going to relax and rest [18:42] cuz you're an energy minimizer, right? [18:44] Mhm. Don't spend that energy if you [18:45] don't have to. [18:46] Is there any animal studies that show [18:48] how um how doing challenging exercise so [18:51] cognitively challenging exercise so [18:53] exercise that involves problem solving [18:56] improves our neuroplasticity or [18:58] increases our the amount of brain cells [18:59] we have across our brain? Yes. Yeah, [19:01] there there have been and the [19:03] a great um [19:04] impetus for our work was some of the [19:06] work done in rodent studies [19:08] um by uh a professor named Gerd [19:10] Kempermann um and he and his group did [19:14] some work in in mouse models where they [19:16] combined uh access to running wheels [19:19] with a very enriched cage environment. [19:23] Um so they looked at they they did a [19:24] very careful study where they looked at [19:26] some mice who were just living in their [19:28] cage, you know normally a control group. [19:30] They looked at mice that were given [19:32] access to a running wheel. They looked [19:34] at mice that were given access to this [19:36] enriched environment this cognitively [19:37] challenging and things to play on and [19:40] then they looked at a combined group [19:41] where they combined the running wheel [19:43] with the enriched environment and they [19:45] found this effect where the combined [19:47] environment doubled the growth and [19:51] survival of new neurons compared to [19:53] either [19:54] wheel running alone or cage enrichment [19:56] alone. So, you got this really cool [19:58] additive effect [19:59] where you where you really enhance the [20:01] effects of either one of those behaviors [20:04] by combining them. If we can pull that [20:07] conclusion over to human life, [20:09] if we can if one assumes that the same [20:11] effect will be seen in humans, what does [20:13] that then tell us we should be doing if [20:15] we if our objective is to [20:18] live long, happy, healthy lives with [20:20] fantastic brains, what should we then be [20:22] doing exercise-wise? Well, I think [20:23] number one is just getting active, [20:25] right? So, I think, you know, to me the [20:28] number one recommendation is, you know, [20:31] to be physically active. And especially [20:33] for people who aren't that active right [20:35] now, um the best thing they can do is [20:37] get out and and start walking. Um but, [20:39] if we want to enhance the effects of [20:41] physical activity on the brain and build [20:43] on this animal work, we're starting to [20:45] see some good evidence that if you do [20:47] something similar, if you combine [20:49] physical activity with cognitive [20:50] challenges, you can boost the effects of [20:53] physical activity on um on the brain on [20:55] on especially cognitive uh performance. [20:58] And so, you know, most of the work has [21:01] been in controlled environments. So, [21:03] we've done a study where um we built a [21:06] uh a game that you can play while you're [21:07] on an exercise machine. Um so, you [21:10] combine exercise with challenging [21:12] activities, right? Um and we've shown [21:15] that you can actually get a bigger [21:17] benefit for cognition when you do that [21:19] than when you just exercise or you just [21:21] play a game. And so, we can, you know, [21:24] take that and perhaps translate that [21:26] into the real world and think about ways [21:28] that you can [21:29] um make your exercise more cognitively [21:31] challenging. So, can you go out and and [21:34] um challenge yourself spatially? Take [21:36] new routes, right? Often times, [21:38] especially runners or or walkers, they [21:40] just do the same route every time or the [21:42] same they have two or three routes that [21:43] they do every time depending on how long [21:45] they want to go. But, maybe we should be [21:47] challenging ourselves a little more, [21:48] right? Maybe we should take new routes [21:50] where you get a little lost and then [21:52] have to find your way back, right? I'm [21:54] someone that runs on the treadmill, but [21:56] Jack over there, he runs outdoors. [21:59] So, you're telling me, sort of top line, [22:02] that Jack is serving his brain more than [22:04] I am when I'm just on that same [22:05] treadmill every day in my hotel room [22:07] while I'm out here in New York, whereas [22:08] he's running around Central Park. It's [22:10] possible. So, I think there's there's a [22:12] couple things. [22:14] Um you know, running on a treadmill may [22:15] end up being a little more like running [22:17] on a running wheel for a mouse without [22:19] the extra enrichment. And yeah, running [22:21] outside may provide some of those better [22:24] benefits. We also know that running [22:26] outside actually has a lot more uh [22:28] benefits than just maybe cognition, but [22:30] also seems to boost mood a little bit [22:33] more than running or exercising in more [22:36] impoverished environments, you know, cog [22:38] you know, um Really? Uh yes. So, there's [22:41] like there's a research movement called [22:43] the green exercise movement that is uh [22:46] focused on [22:47] uh the impact of exercising in green [22:49] spaces versus um [22:52] more urban environments or or on indoors [22:54] on exercise equipment. And I don't want [22:56] to scare anybody. Like I said, exercise [22:58] is great. If if you if running on a [23:00] treadmill works for someone's lifestyle, [23:02] it is fantastic exercise, right? [23:04] know what I mean, I could go outside. [23:06] So, the only reason I'm not is because I [23:09] don't know the difference. Right. So, [23:11] you know, it's for for someone like me, [23:13] of course I could have gone outside this [23:14] morning instead of just um being on the [23:16] treadmill. But, I've I did I thought [23:18] they were the same. So, you're telling [23:20] me that there is potentially some [23:21] upside, according to research, in me [23:23] getting outside and running in both mood [23:25] and neuroplasticity makes me go, "Okay, [23:27] tomorrow I'll make a different [23:28] decision." Absolutely. I think that I [23:29] mean, to me that's the really surprising [23:31] outcome of a lot of this research is [23:33] that uh moving outside and especially [23:36] moving in green spaces, so moving in [23:39] um parks or near parks or uh moving on [23:41] trails, things like that, seems to uh [23:44] have bigger benefits, especially for [23:46] mood. We don't know yet about the [23:48] cognitive benefits. That's our [23:50] hypothesis, but certainly uh some of the [23:52] research out there suggests that for [23:54] mood and feelings of well-being, moving [23:56] your body in a green space provides a [23:59] little bit extra benefit than moving in [24:01] um in in like I said, in city streets or [24:04] in in indoors. One of the things I I [24:06] notice all the time is if I exercise [24:09] before I do this podcast, my brain just [24:10] seems to work. Yeah. Whereas if I get [24:12] out of bed and I don't exercise and then [24:15] I come and do this podcast, it's like [24:16] the words just don't go from my brain to [24:18] my mouth properly. Yeah. I mean, that's [24:20] why I got into this, right? Because I [24:22] started noticing the same thing. And I [24:24] started noticing how much better I felt [24:27] after I exercised. And, you know, on and [24:29] and to this day, right? I mean, my wife [24:31] knows when I didn't go for a run in the [24:33] morning, right? I'm not that pleasant of [24:35] a person to be around the rest of the [24:36] day. What is going on there? Do you Do [24:38] you know the sort of physiological [24:40] reason why it feels like if I exercise [24:42] in the morning before I have a two-hour [24:44] conversation, my brain and mouth seem to [24:46] be connected? [24:47] One of the things that I I think is [24:49] happening is that um you've activated uh [24:52] reward centers in your brain that have [24:54] increased your arousal, right? They've [24:56] you've activated these centers in your [24:58] brain um that are making you feel good. [25:00] And when we feel good, we feel more [25:02] confident. Um we're not as sort of stuck [25:05] in our heads. We're not as we're we're [25:07] more present. Um but, I think that is [25:10] rooted in the rewarding sensations of [25:12] exercise, right? It it makes us feel [25:14] better. And when you feel better, you [25:16] function better across all aspects of [25:18] your body or of of your life. Um and [25:21] those rewards are molecular rewards that [25:23] are that are popping up. It's There's [25:25] There's similarities with um with how [25:27] you people feel when they use certain [25:29] drugs. They're activating similar [25:31] receptors in your brain as when you're [25:32] using certain drugs, although to a much [25:34] lower extent. Um and it's really it's [25:37] making you, you know, sharper and and [25:39] making you more confident and making you [25:40] feel better. Is there a optimal time of [25:43] day to exercise? I know to your point um [25:45] about any exercise is better than no [25:47] exercise, but [25:49] is there an optimal time to exercise? I [25:51] mean, when do you exercise and why? [25:52] Well, I exercise first thing in the [25:54] morning. Why? Um because I will feel [25:56] better all day. Right? And so, I mean, [25:58] there's two reasons. I think one, if I [26:00] save exercise for later in the day, [26:01] there's a greater chance that things [26:03] will come up and I'll, you know, I'll [26:05] I'll find excuses not to. But, mainly [26:08] it's because first thing in the morning, [26:09] if I exercise, my whole day is better, [26:12] right? And so, that's the motivation to [26:14] get out of bed for me and and get out [26:15] the door is I literally think about how [26:18] I will feel if I don't do it. Um cuz [26:21] sometimes it's cold. Sometimes you don't [26:23] it's dark, you know, this time of year, [26:24] you don't want to do it. But, if I think [26:27] about how I'll feel the rest of the day, [26:29] um [26:30] that's a big motivator. And people might [26:32] hear this and they they might be [26:33] starting from zero, right? They might [26:35] not be exercising at all. [26:37] What would you say to those people? Not [26:39] to be intimidated by the advice out [26:43] there about how much you have to [26:44] exercise because it's actually [26:45] surprising how little you need to [26:47] exercise to gain benefits. Um so, if [26:50] you're starting from zero, the biggest [26:54] bang for your buck from a public health [26:56] standpoint are people who are starting [26:57] from almost zero and just starting to [27:00] exercise a little bit, right? Just [27:03] getting out the door and taking a [27:04] thousand steps, right? Something like [27:06] that. If you know, those those sorts of [27:09] uh [27:10] small amounts going from zero to two, [27:13] three, four thousand steps per day of [27:15] exercise, that's that's the biggest [27:17] public health benefit. Then you start to [27:19] see diminishing returns, right? So, if [27:21] you're if you're already exercising a [27:23] lot and you and you want to bump it up a [27:25] little higher, you know, the amount of [27:27] benefit you get is is smaller than going [27:29] from very little to to more. But, I [27:32] think that's the I mean, that's the [27:33] surprising thing for me is that, you [27:35] know, if you if you are not an [27:38] exerciser, getting four or five thousand [27:40] steps per day is going to give you a big [27:43] cardiovascular benefit and a big benefit [27:45] for your brain. You've studied some of [27:47] the tribes around the world. So, the [27:48] Hadza tribe, right? Is that [27:49] Correct. Yes. [27:50] What what work have you done with them [27:52] and when did that research begin? So, I [27:55] started working with uh the Hadza in [27:57] 2009. That was my first time out there. [28:00] And we've been working with them and [28:02] interested in um what kinds of um health [28:07] impacts you see in a hun- in the context [28:10] of a hunting and gathering lifestyle. [28:11] And they live in what part of the world? [28:13] So, they live in northern Tanzania. Why [28:15] did you want to spend time with them? [28:16] So, the Hadza uh provide a window into [28:21] what a hunting and gathering lifestyle [28:22] looks like. And so, if if you work with [28:24] individuals who are still um pretty much [28:27] full-time hunting and gathering, um they [28:30] give you a view of how much physical [28:32] activity does it take to be a [28:33] hunter-gatherer, for example? And how [28:36] does that relate to biomarkers of [28:38] cardiovascular health or how does that [28:40] relate to their cognition? Um how does [28:42] this lifestyle impact the way that they [28:44] age? And the Hadza give us this really [28:47] important view of what that lifestyle's [28:50] like in terms of [28:51] behavior and activity and and um and [28:54] aging. [28:56] Is there a optimal amount of exercise [28:58] that's in line with our sort of [29:00] evolutionary past? We said, you know, [29:02] that we've evolved to be um active. Was [29:04] there Is there like an average amount? I [29:06] mean, do we see this in the Hadza [29:07] tribes? Do we have any clues from [29:09] history? Yeah, I mean, it so, we can [29:13] look at what living hunter-gatherers do, [29:15] and that provides us with kind of a clue [29:17] as to what that lifestyle um might [29:19] entail. And I like I do like to think [29:21] about things in terms of steps per day [29:23] often because that's an easy metric for [29:25] people to kind of understand and track [29:27] for themselves. There are more [29:28] complicated ways to to measure physical [29:30] activity, but steps is a good one, step [29:32] counts. And so, um the Hadza that we as [29:36] we've measured their step counts are [29:37] getting a lot. So, it's like, you know, [29:39] 15 to 20,000 steps per day in that [29:42] range, which is quite a bit of of [29:44] movement. And that's not to say that [29:46] that is the optimal amount, um but [29:48] that's what we see in hunting and [29:49] gathering lifestyles. The benefits that [29:52] we get from a public health standpoint [29:54] start to occur at much smaller levels, [29:57] right? So, you know, 4 5 6,000 steps per [30:00] day you start to see some real benefits. [30:02] And as I said, you start to maybe see [30:04] diminishing returns as you get higher [30:06] and higher levels. So, what's what what [30:09] we see in the past or see in living [30:11] hunter-gatherers may be quite different [30:13] than what's necessarily you know, [30:15] optimal for our health in terms of you [30:17] know, where are we going to get the most [30:18] benefit and and where do we start to [30:20] trail off. With the Hadza, is that [30:22] across all age groups? Or is that Yeah, [30:25] I mean, there is a decline in physical [30:27] activity with age. That's clear. But um [30:30] but even older adults we've measured [30:33] physical activity in adults in their 70s [30:35] and even their early 80s and they're [30:37] still far exceeding what we do in in in [30:41] in the US or the UK or By factor of? A [30:44] lot of times the way that we measure [30:46] physical activity is in terms of how [30:48] much time they spend in moderate or [30:50] vigorous intensity activity. [30:52] Um so, these are kind of activities that [30:54] are that get your heart rate up up to [30:56] about 50 55% plus of your of your [30:59] maximum heart rate. And older adults are [31:01] still engaging in 60 70 80 minutes per [31:05] day of that kind of activity, whereas [31:08] say in the US you might see older adults [31:11] on average [31:12] engaging in two to four minutes per day [31:15] of that level of activity. Two to four [31:17] Yeah, so on average, right? For for [31:20] older adults. So, we just don't see as [31:22] much physical activity in in the US. [31:25] Like I said before, only 25% of adults [31:28] in the US meet physical activity [31:30] guidelines and physical activity [31:32] guidelines here are 150 minutes per week [31:35] of moderate to vigorous physical [31:36] activity. So, in the US 25% of adults [31:40] meet those guidelines. In the Hadza, [31:43] those that we have measured are meeting [31:45] weekly activity guidelines on average in [31:48] two days. So, they're getting [31:51] 300 minutes of physical activity in a [31:54] couple days versus you know, adults in [31:57] the US who aren't coming close to that. [31:59] One of the biggest killers, I think [32:00] maybe the biggest killer of people in [32:02] the US and I believe in the UK as well, [32:04] is cardiovascular diseases. [32:06] Yeah. Is am I right in thinking that is [32:08] the single biggest That's the disease [32:10] you're most likely to die from? Yes, I [32:12] believe so. When we look at the Hadza, [32:14] how are they doing in terms of [32:15] cardiovascular illness? So, we don't see [32:18] a lot of evidence of disease risk. So, [32:21] we we have not yet measured [32:24] cardiovascular outcomes like we haven't [32:26] measured mortality for example from [32:28] cardiovascular disease, but we have [32:30] measured biomarkers. So, things like [32:32] cholesterol levels, triglyceride levels, [32:35] blood pressure. So, looked at whether [32:37] there's hypertension and we see very [32:39] little evidence of cardiovascular [32:41] disease [32:42] in this group. Others other researchers [32:45] have looked at other [32:46] Um there's a long-term study of a group [32:49] in South America called the Tsimane [32:51] that have been studied in a lot of [32:52] detail and there they found almost no [32:55] evidence of cardiovascular disease and [32:57] they've been able to look in a much more [32:59] detailed way at outcomes like you know, [33:01] death from cardiovascular disease and [33:03] they see almost no evidence of [33:05] high levels of cardiovascular disease. [33:07] Diabetes? Very little evidence of [33:09] diabetes, very little evidence of [33:11] dementia. I mean, these diseases that we [33:14] look at as inevitable parts of aging, [33:17] they're just not, right? They are not [33:19] inevitable. A lot of them are a product [33:22] of our lifestyle. And you know, I'm I'm [33:24] most familiar with dementia and [33:26] something like 40% of risk of dementia [33:30] is preventable. It's due to lifestyle. [33:33] Right? We have the ability to modify our [33:36] risk in really big ways by altering the [33:39] way we live. What else has inspired you [33:42] or caused you to implement behavioral [33:43] changes into your life, new habits based [33:45] on [33:46] your work researching the Hadza tribe? [33:49] Is there anything at all that has [33:51] either changed your mind or modified how [33:53] you live your life? Yeah, I mean, I [33:54] think a couple of things. Number one, [33:58] physical activity is is sort of the [34:00] cornerstone of my life. That's sort of [34:03] that is that is [34:04] that's been driven by my personal sort [34:07] of [34:08] enjoyment of it, but also from a [34:10] research standpoint that's been really [34:12] motivating to maintain an active [34:13] lifestyle across these years. But more [34:16] recently I've been really interested in [34:18] sitting, [34:19] which is you know, in some ways [34:22] it's it's not really the opposite of [34:24] being physically active, but it's it's [34:27] another behavior that we engage in [34:28] actually for much more time per day than [34:30] than anybody's physically active. And [34:33] we've done a lot of work on resting [34:35] behaviors in the Hadza and that's been [34:37] an area that I've sort of tried to pull [34:39] into my life as well as [34:41] trying to understand you know, how [34:43] sitting can impact our lives and then [34:46] how our evolutionary biology may [34:50] may be tweaked by by this behavior. And [34:53] so, I've tried to implement some things [34:55] like trying not to sit too long, trying [34:57] to break up my sitting, [34:59] finding ways to [35:01] to not be stuck on in a chair all day. [35:05] And a lot of that's driven by by my [35:06] research. What's the what's the issue [35:08] with sitting? So, sitting is sitting's a [35:11] beautiful thing, right? I mean, we're [35:12] doing it right now. It's really [35:13] comfortable. [35:14] And the reason it's comfortable is [35:15] because we've basically taken all of the [35:18] load off of our lower body. So, we're [35:20] we're supporting ourselves in these [35:22] chairs, right? You got to move around [35:24] Now that you mention it, I'm not You [35:25] know, when I give talks about sitting [35:27] all of a sudden I start seeing people [35:28] fidgeting, right? Some people get up and [35:30] and stand up in the back. So, you know, [35:33] you take the load off of your lower legs [35:34] and your muscles don't have to work and [35:36] you know, not surprisingly that's super [35:38] comfortable. We're not working hard. [35:40] But at the same time what's happening is [35:43] the our muscles not being active means [35:45] that what we normally do to fuel muscle [35:48] activity, which is you know, we break up [35:50] triglycerides in our bloodstream and [35:51] that's you know, that's those are broken [35:53] up into fatty acids that fuel muscle [35:55] activity, that's not happening. And so, [35:58] those those fuels now build up in our in [36:02] our blood vessels and that's associated [36:04] with cardiovascular disease. So, sitting [36:07] for long periods of time is associated [36:09] with some negative health outcomes. And [36:12] one of the things that we've learned [36:13] from working with the Hadza is that you [36:16] know, [36:16] people rest a lot. Like the Hadza, they [36:20] sit for as or or rest and sit for as [36:22] long as we do, which was actually super [36:24] surprising to us. We thought that [36:25] wouldn't be the case. We thought they [36:26] were going to be active you know, all [36:28] the time and there would be much less [36:29] sitting, but when we finally actually [36:30] measured it with accelerometers, [36:32] they're resting for the same amount of [36:34] time that we are. [36:35] But they're not sitting in chairs. [36:37] They're resting in postures that require [36:39] a little muscle activity. So, they're [36:41] squatting or they're they're kneeling or [36:43] they're sitting on the ground in ways [36:45] that you know, you have to kind of keep [36:46] shifting your body around. [36:48] And it's possible that just that kind of [36:51] low level of muscle activity [36:53] is is how our bodies are well adapted to [36:56] rest. And what's weird is the invention [36:58] of chairs. What's weird is the invention [37:01] of these objects that completely [37:03] eliminate the need for our lower bodies [37:05] to use muscle activity. A A chair is a [37:07] fairly new invention. When when did [37:09] chairs come into the picture? The first [37:10] chairs that we know about from the [37:12] archaeological record are about 5,000 [37:14] years old. Um but you know, the [37:16] ubiquitous use of chairs is is probably [37:19] even more recent than that, right? [37:21] Chairs are chairs are these weird [37:22] objects that they're not only you know, [37:25] ergonomic and and and made for you know, [37:28] our comfort, but they also over history [37:30] have had implications for economic [37:32] status and power and you know, taking a [37:34] seat at the table and a throne in in you [37:37] know, in in terms of political power. [37:40] Where you sit is always been important [37:42] from a political and and economic and [37:44] social standpoint. So, chairs have have [37:47] sort of taken on a big part of our [37:49] lives. And if you you know, if you walk [37:51] into someone's house, you know, [37:54] generally the first thing that you're [37:55] seeing is their seating environment, [37:57] right? Chairs and couches and [38:01] and and places to sit are part of the [38:04] way we design our world. [38:06] We don't think about them that often, [38:08] but we use them more than almost any [38:10] other object in our lives. It's kind of [38:12] like we assume they've just always been [38:13] a thing. It's probably most things in [38:15] our life we assume that this is just the [38:16] way it's always been and this is [38:17] therefore normal and acceptable. [38:20] But it must be pretty illuminating to go [38:22] and see these tribes who [38:24] they must think we're crazy. They must [38:25] think we're so strange by the things [38:27] that we do. I mean, they do, but at the [38:29] same time, you know, when we work in in [38:32] Hadza land, we bring chairs cuz they're [38:34] comfortable. And you know, the the first [38:36] thing that happens when we're out there [38:38] is you know, this crazy game of musical [38:40] chairs that if one of us gets up, you [38:42] know, someone comes over and sits in our [38:43] chair. And why is that? Cuz they're [38:45] super comfortable. Um and so, I don't [38:48] think they they necessarily think we're [38:50] crazy. I think they [38:51] you know, they enjoy sitting in the [38:52] chairs. [38:54] Um they just don't have them. Be careful [38:55] not to leave any of them there cuz [38:56] Well, that's what you know, that's what [38:58] happens is you know, we'll go out for [38:59] the day and and go you know, go [39:02] you know, foraging with people and and [39:04] come back and you know, you can't find [39:05] You want to sit down and you can't find [39:07] a chair cuz everyone's sitting in your [39:08] chair, but that's totally fine. They [39:11] they deserve to rest just as much or [39:12] more than than anybody else. What's the [39:15] practical advice do you think there for [39:17] for employers, for people that work at [39:19] home, for people that sit in chairs [39:20] often because we [39:22] people can't just we can't just do this [39:24] podcast squatting. Right? Well, we [39:25] could, but you know what I'm saying? [39:27] challenging. It'd be very very [39:28] challenging. Is there some kind of [39:29] middle ground that is accessible and [39:31] realistic for us? Yeah, I think the I [39:33] think the best thing people can do is [39:35] just try not to sit for prolonged [39:37] periods of time. I mean, there's no way [39:39] to eliminate sitting and I don't think [39:41] that standing all day is is necessarily [39:43] the answer. I don't think that that's [39:45] necessarily a a [39:47] benefit full-time. I think breaking up [39:49] sitting into smaller periods is probably [39:51] the best thing we can do. [39:53] Um so, you know, one of the pieces of [39:56] advice is is actually that I always tell [39:58] people is, you know, just drink more [39:59] water so you got to get up and pee more. [40:01] Um that is That's an easy way to to kind [40:03] of force yourself not to sit for 2 hours [40:05] at a time. But, you know, having those [40:07] kinds of reminders that you should get [40:10] up, move around. [40:11] Um there's been this popular notion of [40:13] taking exercise snack break. So, you [40:16] know, every 30 minutes, every 45 [40:17] minutes, get up and walk up a staircase [40:20] or do some push-ups or something just to [40:22] get your body moving, get your muscles [40:24] working, do some squats. [40:26] Um and so, that can be, you know, really [40:28] beneficial. [40:29] Some people hear that and go, "Hippa, if [40:31] just doing just getting up and doing a [40:32] 2-minute walk, how's that going to help [40:34] in the grand scheme of things?" There's [40:35] really good evidence. So, okay, couple [40:37] things. Um [40:38] from an epidemiological standpoint, [40:40] there's been this really great work [40:41] coming out on [40:43] um something that's called vigorous [40:45] intermittent physical activity. [40:48] Um so, this is [40:49] um [40:50] activity that's not purposeful. It's [40:52] short duration, but it's vigorous. So, [40:54] going up the stairs or walking really [40:56] briskly for like a minute or two. [40:59] That in the long run, people that do [41:01] that often have a lower risk of [41:02] mortality and a lower risk of [41:04] cardiovascular disease, regardless of [41:06] purposeful physical activity, right? So, [41:08] you can actually get big benefits by [41:11] just doing these short bursts of [41:13] activity. Walking to get your lunch or [41:16] at a vigorous pace. [41:17] At a vigorous pace, okay. [41:18] Right? Yeah, I mean, walking to get your [41:19] lunch is great, but you get a little bit [41:21] more benefit from doing it at a vigorous [41:24] pace. So, you know, if you're walking [41:25] and you can't sing at the same time or [41:28] you can't talk at the same time, that's [41:30] that's now you're getting into kind of a [41:32] vigorous intensity. Um and there's also [41:35] been randomized controlled trials where [41:36] people have actually in the lab had [41:39] people sit for, you know, 8 hours, not [41:41] do anything. And then they've taken [41:43] those same people on another day and had [41:45] them sit but break it up into, you know, [41:47] 20 minutes, break it up and walk on a [41:49] treadmill for 2 minutes, something like [41:50] that. And those studies have shown [41:53] changes in cardio-metabolic markers. So, [41:56] they've shown shown changes in um [41:58] insulin levels and changes in [42:01] um in triglyceride levels and and [42:04] cardiovascular disease biomarkers just [42:06] from breaking up your sitting in into [42:08] into shorter periods. So, you really can [42:10] have a a profound effect, I think, on [42:12] your health um by implementing some of [42:15] these small changes. [42:17] Is there, you know, a type of exercise I [42:20] have we touched on this a little bit [42:21] earlier on, but I'm really trying to [42:23] make a case to myself that I should be [42:25] doing more aerobic exercise [42:27] than I typically do a little bit of [42:29] aerobic exercise um unless I'm training [42:32] for something in particular and a lot of [42:33] sort of resistance training. Is there [42:36] any case that I should be doing more [42:37] aerobic exercise or resistance training [42:39] if my goal is to [42:42] improve my brain, my memory, my [42:43] cognition? I think I mean, I think both [42:46] are important. [42:46] Mhm. Um [42:48] from from my perspective, aerobic [42:50] activity, you know, we're we're thinking [42:52] about this from an evolutionary [42:53] standpoint, right? We've been talking [42:54] about this idea of can we boost the [42:57] effects of exercise by adding cognitive [42:59] challenges, right? And so, from my [43:01] perspective, aerobic activity is [43:03] probably the place where you can do that [43:06] um in the easiest way. Um so, by moving [43:09] yourself outside a new environment, um [43:11] by adding in some some spatial [43:13] navigation challenges to a workout, you [43:16] might be able to do that a little easier [43:17] than when than when you're lifting [43:18] weights. You know, this whole brain [43:20] training industry that emerged I think [43:22] it emerged like 10 years ago and there [43:23] became all of these apps that were kind [43:25] of like puzzles and stuff and they [43:27] claimed that if you use these apps and [43:28] do this brain training stuff, then it [43:30] will [43:31] um make your memory better, your IQ [43:33] higher, all of these things. Is there [43:34] any merit to these brain training games? [43:38] There does appear to be some. Um so, [43:39] there do appear to be some training [43:42] games that that do improve aspects of um [43:46] of cognition. Uh you know, it's been a [43:48] it's been a tough industry because not [43:50] all of the studies are super high [43:52] quality um and and some of the claims [43:54] can be a little bit further ahead of [43:56] maybe where the science is. So, are the [43:58] effects that big? Like if you do it, you [44:01] know, every day and you invest all this [44:03] time, are you going to get the biggest [44:05] effect? Um but there does appear to be [44:07] some benefit. You know, if I were in a [44:11] perfect world, would I be doing [44:13] everything I could [44:14] um to stave off the potential for [44:16] developing dementia? Yes. And so, if [44:18] there's a little bit of evidence that [44:20] that could be helpful, I would I would [44:22] definitely jump in and do it. Just [44:24] learning generally. Yeah, learning So, [44:27] learning [44:28] education, [44:30] um keeping yourself cognitively [44:32] challenged throughout your lifespan is [44:34] clearly um a way to keep staving off [44:39] cognitive decline. Is there research to [44:41] support the idea that learning or [44:42] reading or some kind of education? [44:44] Yes, for sure. For sure. And and, you [44:45] know, education is a difficult one [44:47] because education is wrapped up in a lot [44:49] of other things, right? So, education is [44:51] wrapped up in um your parents and [44:54] socioeconomic class. And so, when we [44:56] study education from an epidemiological [44:58] standpoint, it's really hard to deal [45:00] with um the kinds of other variables [45:02] that could confound those relationships. [45:05] But certainly lifelong learning seems to [45:07] be associated with better reserve. So, [45:09] one of the things that we think about in [45:10] terms of cognitive aging is how much [45:12] reserve do you build up over the course [45:14] of your lifespan so that as we undergo [45:18] some atrophy and decline, which isn't [45:20] which is kind of inevitable, um have you [45:22] built up enough reserve so that that [45:25] decline doesn't impact your daily life, [45:27] right? You you have enough of this [45:29] built-up tissue and built-up reserve and [45:31] built-up connections [45:33] um that even if you undergo some decline [45:35] or in in tissue, it doesn't impact you. [45:38] Reserve being kind of like pathways. Is [45:41] that what Reserve could be pathways. [45:42] Right. It could be volume. Volume, okay. [45:44] So, it could be a bigger hippocampus or [45:46] it could be the connections between your [45:48] hippocampus and and other parts of the [45:50] brain. And both of those are are [45:52] important and you can build those up [45:54] across your lifespan with physical [45:56] activity, with um [45:58] cognitive engagement, um things like [46:00] that. And with avoiding some of the sort [46:04] of negative health behavior like smoking [46:06] or excessive alcohol use. Does excessive [46:09] alcohol use mean drinking shrink the [46:11] brain? They do. They are They are risk [46:12] factors in cognitive decline and the [46:15] development of dementia and Alzheimer's [46:16] disease. How much alcohol? [46:18] We know that excessive, like, you know, [46:20] excessive consumption over the sort of [46:22] one drink per day or two drinks per day [46:25] for a man, one drink per day for a [46:26] woman, [46:27] um [46:28] that level of alcohol consumption is [46:31] associated with negative health outcomes [46:33] including [46:34] risk of dementia and Alzheimer's [46:35] disease. [46:37] Is So, sleep is the other one that's a [46:39] big a big factor in cognitive decline, [46:41] right? [46:42] And sleep is I mean, a lot of things [46:44] happen during sleep um that are really [46:46] important. One of the things that [46:48] happens during sleep, we think, is that [46:50] um it's a time where your brain is [46:53] clearing these plaques that can build up [46:56] that are associated with um [46:59] neurodegenerative disease. And so, if [47:01] that's the case and there's been some [47:03] evidence that suggests that that sleep [47:04] is when some of that clearance is [47:06] happening, then poor sleep quality [47:09] just doesn't allow that function to [47:11] occur, allows those uh plaques to build [47:13] up. Sleep is weird in some ways because [47:16] it's not always more is better. [47:18] So, uh it follows a U-shaped curve in [47:21] terms of risk of developing dementia, [47:22] for example, where less sleep [47:26] and lots of sleep are both associated [47:29] with higher risk. And there's like a [47:30] sweet spot, right? There's a sweet spot [47:32] of, you know, call it 7 and 9 hours a [47:35] night, something like that. Um that [47:38] that's that is where your lowest risk is [47:40] going to be. So, you can oversleep. You [47:42] can. Here's the the the the caveat to [47:45] that is what's going on with [47:48] oversleepers that you're not able to [47:51] suss out in your analysis. So, a lot of [47:53] times people oversleep because they're [47:55] depressed. And we know depression is [47:56] linked with these neurodegenerative [47:58] diseases. And so, it's it's possible [48:02] that it's those it's not the actual [48:03] sleep itself, but it's what's linked [48:06] with too much sleep. [48:07] Like inactivity. They might not be [48:08] exercising as much as I am. [48:10] Yeah, what are you displacing? So, [48:11] another Yeah, that's a great point. [48:13] Another thing that we can look at is, [48:15] you know, you have 24 hours in a day, [48:17] right? And so, if you sit for an extra [48:20] hour, that's going to come at the [48:22] expense of something else. If you sleep [48:24] for an extra hour, yeah, or exercise or [48:27] light physical activity, just housework [48:29] or something. [48:30] Um so, you can't [48:32] the day is not infinite. So, anything [48:34] that you choose to do is displacing [48:36] something else. What about having [48:38] friends? Yeah, having a partner, you [48:40] know, does that is that going to [48:42] increase my chances of having a great [48:44] cognitive function and a big brain? [48:46] Well, it depends on how good your [48:47] relationship is. [48:49] So, I mean, just having a partner [48:50] sometimes, you know, if it's if it's [48:52] there are ways that that can be [48:54] associated with negative outcomes if if [48:56] your relationship is Tell me about it. [48:58] is challenging, right? Um but, you know, [49:00] so I think of healthy aging as linked to [49:03] really three main behaviors. [49:06] Diet, physical activity, and social [49:09] connections. Okay? Social connections [49:11] are key. And so, you know, we're hearing [49:14] now there's a kind of a buzz where the [49:16] epidemic of loneliness, especially [49:18] coming out of the pandemic years, that [49:20] is really um it's kind of frightening [49:22] because people have gotten more used to [49:25] sort of living alone or being alone. Um [49:27] and those social connections are a key [49:29] aspect of maintaining a healthy brain [49:32] when we age. We know that. Um and [49:34] How do we know? Well, mainly from [49:36] epidemiology. There's two ways to two [49:38] ways to analyze these these these [49:40] questions. There are are randomized [49:42] control trials and sort of observational [49:44] trials. [49:45] It's really hard to do randomized [49:47] control trials on loneliness and and [49:49] look at long-term outcomes. So, we look [49:51] at observational data and people who [49:53] have stronger social connections, who [49:55] have um it's not necessarily more, but [49:58] it's it's [49:59] higher quality social connections. So, [50:01] you know, if you ask them if they have [50:03] people they can confide in, they'll say [50:04] yes. Um those people tend to have better [50:07] brain outcomes than people who who don't [50:10] have those connections. And if you think [50:12] about it, again, I I I don't want to [50:13] make a a sort of [50:15] an easy evolutionary argument where we [50:18] just say, "This is how we evolved, so [50:19] this is how we live should live now." [50:22] But I mean, if you think about our [50:23] evolutionary history, for the most part, [50:26] we lived in a in a time where social [50:28] connections were imperative to survival. [50:31] Right? I mean, if you are living in a in [50:33] a hunting and gathering lifestyle, you [50:36] know, you need those social connections. [50:38] You can't guarantee that you will find [50:40] food every day. So, you need to have [50:43] connections with other people who you [50:45] trust and they trust, who you're willing [50:47] to share with. Right? And so, those [50:49] social connections become [50:51] um become inextricably linked to your [50:53] health. Does pollution have an impact on [50:55] our cognitive performance? Yeah, that's [50:57] been so that's been a surprising and [51:00] really kind of sad result of a lot of [51:02] research lately is that air pollution um [51:06] has real negative impacts on brain [51:09] aging. Um and we've seen that in acute [51:12] studies where people have looked at um [51:14] the effects of you know, what's going on [51:17] in your in your peripheral blood when [51:19] you commute in traffic, right? When you [51:21] ride your bike in traffic. Um but also [51:23] from an epidemiological standpoint, [51:25] people who are living in areas with [51:27] higher air pollution have a higher risk [51:30] of developing Alzheimer's disease and [51:32] other dementias. Um one of the things [51:34] that we've done some work on, we were [51:36] really interested in whether physical [51:38] activity either could um you know, [51:40] diminish those impacts of air pollution [51:42] on the brain, but also we were thinking, [51:44] well, when you're active, you're [51:45] breathing more, right? Your your your [51:48] your respiration increases, so you're [51:49] breathing in more uh pollution, more [51:52] particles. So, could that actually, you [51:54] know, have an impact on the benefits of [51:56] activity on your brain? And we found we [51:58] we've looked at a look at this in a [52:00] couple ways and both for some brain [52:02] structural outcomes and for risk of [52:04] dementia, exercising in or being [52:06] physically active in in an area with [52:09] even moderate levels of air pollution [52:11] diminishes the benefits of physical [52:13] activity on the brain. [52:15] Which is a real bummer. Especially for [52:17] me, I live in Los Angeles, which is a [52:19] very uh it's an area with a lot of air [52:21] pollution. And um and so, being [52:23] physically active in that environment [52:25] when there's a lot of pollution in the [52:26] air, um it doesn't it doesn't make your [52:30] health outcome worse, but it diminishes [52:32] the benefits of physical activity. So, [52:35] if you go for a a run in the middle of [52:36] London, for example, or in the middle of [52:38] New York City, the [52:40] cognitive benefits are diminished. [52:42] That's what we're seeing in the data. [52:43] We're seeing and in fact, the study that [52:45] we did was was uh from data uh based in [52:47] the UK where, you know, we're not seeing [52:50] the kinds of levels of pollution that we [52:52] see in some other cities around the [52:53] world where it's really drastic or even [52:55] in Los Angeles where it's much higher [52:57] levels of pollution than we'd see in say [52:58] London. But even in those levels with [53:01] more moderate levels of air pollution, [53:03] um people who are active in in higher [53:06] levels of air pollution don't show the [53:08] same brain benefits as people who are [53:10] active in areas with lower [53:12] pollution. [53:13] I had my brain scanned uh [53:15] what, 2 months ago now? And it was okay. [53:19] Okay. It wasn't [53:21] amazing. It wasn't [53:22] okay? I mean, he just told me there was [53:23] room for improvement in terms of like [53:26] some things he saw in my brain. He also [53:27] diagnosed me with ADHD following that [53:29] and a few other questionnaires and and [53:30] things. One of the things in my sort of [53:33] prescription [53:34] that he asked me to do more of was [53:37] racket sports. [53:38] Interesting. Okay. He said, "If you do [53:40] this list of things that he's asked me [53:42] to do, things like hyperbaric chambers [53:43] and blah blah blah blah blah blah and [53:45] racket sports, um [53:47] we'll see an increase in certain parts [53:50] of your brain." [53:51] Now, that somewhat ties into what you're [53:53] saying with doing this physical [53:56] activity, but pairing it with some kind [53:58] of cognitive challenge. Racket sports [54:00] seems like a prime example. [54:02] it's funny. It it is the number one [54:04] question I get after I give a talk is [54:06] about tennis. And I think I probably you [54:08] know, I give talks a lot in in you know, [54:10] to communities with you know, more [54:13] sometimes more affluent older adults who [54:15] probably play a lot of tennis. And but [54:16] it is, you know, it's an activity that [54:18] people play can play later in life, you [54:21] know, um and um and it does involve a [54:25] lot of strategic thinking, it involves a [54:26] lot of fast reactions, and it involves [54:29] aerobic activity. [54:30] Um and so, it is it's a great contender. [54:32] And you're doing it with [54:33] doing it with someone. It's social. [54:35] Um often times, especially uh when you [54:37] get a little older, you play doubles, um [54:39] so you don't have to run the court as [54:40] much. What are the other questions [54:42] people after hearing you speak? What are [54:43] the other questions that people often [54:45] are most curious about? How much [54:48] activity? That's the big one, right? How [54:50] much do I have to do? Yeah. [54:51] Do I have to do? [54:52] Right. And that's the way people think [54:53] about it. Yeah. And it you know, I think [54:56] have to do. Yeah, and it it [54:58] it's it sort of does bum me out to frame [55:01] it that way because [55:02] um because I think of physical activity [55:04] as as something that as as we were just [55:07] talking about, it improves your whole [55:09] day. Um it's something that many of us [55:12] want to do because of that, right? And [55:14] so, I think, you know, first the first [55:16] thing I always tell people is find the [55:18] activity you want to do. [55:20] Because that's the one you'll keep [55:21] doing. And so, don't look for the [55:22] perfect, right? If running on a [55:25] treadmill makes you crazy and you don't [55:27] want to do it, then you won't keep it [55:28] up. Um if playing tennis does it for [55:31] you, maybe it's not the best if we if we [55:34] can even figure out what that means, but [55:36] you're going to do it for the rest of [55:37] your life, then by all means, that's the [55:39] one to do. And so, I think that is the [55:41] first thing that everyone should be [55:43] thinking about is, you know, what do you [55:45] what do you what makes you excited to [55:47] get out the door and do? Um [55:50] and don't worry about what's best. [55:52] What is the research that you've done [55:54] that you're most [55:55] proud of or that's surprised surprised [55:56] you the most? [55:58] Cuz you know, I've I've been looking [56:00] through your work and found different [56:01] things that I found interesting, but um [56:04] I must have missed something that you [56:06] find really fascinating. Well, one of [56:07] the things that I found really [56:09] surprising was actually it was it's now [56:10] been a while. It's been like [56:12] over a over a decade ago, I did some [56:15] work on um the endocannabinoid system. [56:18] Um and the endocannabinoid system is our [56:20] body's uh sort of natural form of [56:23] marijuana. You know, we produce these uh [56:25] chemicals that activate brain receptors [56:28] the same way that the active ingredient [56:29] in marijuana um activates. And so, um it [56:33] turns out that exercise upregulates this [56:34] same system. Um these endocannabinoids [56:37] and that may be why at least partially [56:39] why exercise makes people feel good. Um [56:41] and one of the studies that we did, like [56:44] I said, about 10-11 years ago now, uh [56:46] was we found that the same thing that we [56:48] get from exercise in terms of [56:51] endocannabinoid signaling, dogs also get [56:53] that. And I'm I'm a dog lover and and I [56:56] know my dog loves to exercise and she's, [56:58] you know, bummed out if she can't get [57:00] her her her walk and run in for the day. [57:03] And I think there's something similar [57:05] are going on. It's these similar [57:06] rewarding mechanisms that make them feel [57:08] good that that makes us feel good. So, [57:10] that was one um one really fun and and [57:13] interesting kind of finding that I think [57:15] has some implications, right? It's it's [57:18] if if if we can find those activities [57:20] that generate those rewards, we're going [57:21] to want to do that more often. And it [57:24] also provides a sort of physiological [57:26] explanation as to why some people who [57:29] don't exercise or unable to exercise can [57:32] often have depressive symptoms. Agree. I [57:34] totally agree. Yeah, and I think these [57:37] biological mechanisms that can that can [57:39] make you feel better when you exercise, [57:41] they don't always kick in right away, [57:44] right? And so, I also think they can be [57:45] a that can be a little bit of a barrier [57:47] to someone who's not active that, you [57:49] know, if you just get up and start [57:50] exercising, you know, maybe it takes a [57:52] little bit of time for these things to [57:54] kick in. You have to be able to stay [57:56] within a certain intensity level and [57:58] maybe if you're not very fit, you kind [57:59] of overshoot that and you you end up [58:01] going to too intense and you don't get [58:04] those same sort of mild benefits that [58:06] just make you feel good all day, right? [58:08] I think one of the things that people [58:10] need to kind of keep in mind is is maybe [58:12] try to stick with it long enough to get [58:13] a little bit of fitness so you can reap [58:16] those rewards. They'll come. You just [58:17] need to just give it some time, right? [58:20] Have you got any [58:21] hypotheses that you're working on at the [58:23] moment [58:24] that you haven't been able to prove out [58:25] yet, but you know, as someone that's a [58:27] researcher and that's insanely curious, [58:28] there must be things in your mind that [58:30] you're thinking, "I'd love to do a study [58:31] on that to figure out if that's [58:33] true?" Yeah, I mean, so a couple things. [58:36] I mean, one, we are not done with the [58:39] combining cognitive challenges with [58:40] physical activity. I think that is a [58:42] really um [58:44] a really exciting area and it's it's [58:47] early on. So, I think the the work that [58:49] we've done and others have done is in [58:51] its infancy in how we can boost the the [58:54] the brain benefits of exercise. And [58:56] that's sort of that's going to be a big [58:58] part of our work going forward is what [59:00] can we do to really um make exercise a [59:02] little more cognitively challenging and [59:04] get those benefits. Um the area that I'm [59:07] that I'm really interested in now um is [59:10] the effects of sitting on the brain. [59:12] And um what are the mechanisms that link [59:17] too much time spent sitting with brain [59:19] health? And how can we kind of manage [59:21] that a little bit better? You know, when [59:23] we think about [59:25] exercise participation, and I've been [59:27] saying, you know, 25% of adults uh [59:30] engage in in [59:31] uh the guidelines for physical activity [59:33] levels in the US. That number hasn't [59:35] changed over the last, you know, couple [59:37] decades. All the messaging, I mean, you [59:39] know, would you could you ever meet [59:41] someone who doesn't know that physical [59:42] activity is important to do? But still [59:44] 75% of people don't exercise. And so I [59:47] don't know what it'll take to to change [59:49] that number. [59:51] But I think maybe we can look at other [59:53] behaviors that we can change. And [59:55] sitting is something that everyone does. [59:57] And so that I think is a really nice [59:59] place to focus to move the needle a [60:01] little bit. So can we get people to sit [60:03] less? [60:04] What are the kinds of interventions we [60:05] can implement that can get people to to [60:08] reduce their time spent sitting and will [60:11] that pay off in terms of brain health? [60:13] And I think that's it's a big question. [60:15] We know that time spent sitting is [60:17] associated with risk of dementia. We [60:18] just we just did a big study looking at, [60:21] you know, if you if you sit for 10 hours [60:24] a day [60:25] compared to [60:26] 9 hours a day, it's about a 10% [60:28] increased risk of dementia. If you sit [60:30] for 12 hours a day, it's about a 60% [60:33] increased risk of dementia compared to [60:35] sitting for 9 9 and 1/2. [60:36] 60% [60:37] 60% versus 9 hours a day. Right. So just [60:39] a couple more hours, right? It's it's a [60:41] non-linear relationship. So once you get [60:45] past about 9 9 and 1/2 hours a day, your [60:48] risk start going up in in a non-linear [60:50] exponential way. And so [60:53] can we alter that? Can we I mean it [60:55] doesn't it doesn't take a lot [60:56] necessarily to go from 12 to 8 hours a [60:59] day. [61:00] So [61:01] maybe that's easier than getting people [61:02] out the door. Maybe we can find some [61:05] find some intervention. So that's what [61:06] I'm really excited about is, you know, [61:08] some of some low-cost ideas, some [61:11] low-investment ideas for people [61:15] that could maybe have a big impact on [61:16] the way they age. I'm thinking about all [61:18] kinds of chairs that vibrate and [61:21] give you an electric shock. I'm thinking [61:22] of how we can implement that into Whoop, [61:24] which is a company I've I'm involved in. [61:27] Totally. Yeah, I mean reminders are one [61:29] way, right? I mean I think tracking your [61:31] behavior. I mean there are it's not [61:33] going to work for everybody, but [61:34] certainly tracking your time spent [61:36] sitting for a couple weeks might [61:38] actually give you a little bit of [61:39] motivation once you realize just how [61:41] much time you spend on these chairs. [61:45] What is brain foods? Is is there such [61:46] thing as a brain food? I I think I much [61:48] of the reason I take omega is because [61:49] people tell me it's good for your brain. [61:50] Yeah. I don't you know, I don't think [61:52] there's a magic pill. [61:54] You know, I think the best evidence that [61:57] we have right now is [61:59] is more plant-based, less meat-based, [62:02] especially less processed meat. More [62:05] plant-based. [62:05] More plant-based foods and and less [62:08] meat. Less meat. [62:09] Yeah. Here's where the difficulty lies [62:11] in all of this research. To study brain [62:14] health, you need to observe people over [62:16] long periods of time. And so you can't [62:18] implement [62:20] a 10-year diet intervention. Just nobody [62:23] will follow it. So all of the research [62:25] that's really strong in this area is [62:27] asking people to report what they eat [62:30] and then tracking what happens to them [62:31] over time. So it's [62:33] it's difficult work, but the best [62:35] evidence is that aspects of the [62:38] Mediterranean diet seem to be linked [62:40] with better brain outcomes. So more [62:43] plant-based, more [62:46] more legumes, more whole grains, less [62:50] processed food, less meat, less sugar. [62:52] These are you know [62:54] these are the obvious dietary [62:56] interventions, right? And I think [62:58] they're they're obvious for a reason [62:59] because they seem to be so good for so [63:01] much of our bodies and you know, so much [63:03] of our cardiovascular metabolic health [63:06] and our brain health. If there was one [63:08] fundamental misunderstanding that most [63:10] people have [63:12] that your work and your experience has [63:16] rebuttled, I guess. [63:17] What is that fundamental human [63:19] misunderstanding about the nature of our [63:21] bodies and how we're supposed to be [63:23] living to be optimal? I think [63:26] I think the most dangerous [63:27] misunderstanding is how much exercise it [63:29] takes to get benefits. Right. And I [63:32] think that's because that acts as a [63:33] barrier to people. And what we've seen [63:36] from the epidemiological work is that, [63:39] you know, the the [63:41] there are minimal amounts of activity [63:43] that provide big benefits. [63:45] More is generally better, but you can [63:47] get huge benefits just by moving your [63:49] body a little bit every day. And so I [63:51] think that's, you know [63:53] as I said, it's a dangerous [63:55] misconception because it's a barrier. [63:56] When someone thinks when someone doesn't [63:58] exercise at all and thinks I need to get [64:00] 12,000 steps per day and I'm tracking it [64:03] and I'm getting 3,000, that's a pretty [64:05] big gap and that's one that maybe [64:08] you don't think you can fill. But if [64:10] you're getting 3,000 and you think if I [64:11] get to 5,000, I'm going to get a big [64:13] benefit [64:15] that's motivating, right? [64:17] Is it so true that sometimes going from [64:19] zero to one feels so [64:23] inconsequential [64:25] and somewhat embarrassing [64:27] that we just don't do it because we I [64:28] think many people think of zero to one [64:30] is like zero to a [64:33] five-day-a-week gym attendance record. [64:36] Right. Which is just like climbing Mount [64:38] Everest in your mind. [64:39] It's just so far away that there's going [64:41] to be so much psychological discomfort. [64:42] It's going to result in procrastination. [64:43] You're going to do something else and [64:44] you're going to avoid it. But if we [64:46] reframe that to zero to one being [64:49] walking for your lunch. Yeah. And that [64:51] as the starting point and then one to [64:53] two being as you said going from 1,000 [64:55] steps to maybe 2,000 steps. Feels like [64:56] something everyone can do, but we just [64:58] don't think it's important. We think [64:59] it's totally inconsequential to [65:01] go for a walk as opposed to [65:03] um [65:04] you know, just sitting down and ordering [65:05] our food on an app. Yeah. Something that [65:08] I I think about a lot cuz even someone [65:10] like me that I I go to the gym, you [65:11] know, [65:13] as frequently as I possibly can. [65:15] However, there are some days like today [65:18] where I'm extremely busy where I might [65:21] have said I was going to go to the gym [65:21] late at night and I either think to [65:24] myself that [65:26] there's no middle ground. I think that's [65:27] either going to the gym and working [65:29] really hard or [ __ ] it. Yeah, yeah. [65:31] There's great middle ground now. Yeah. [65:33] You can run up the stairs on your way to [65:34] bed, right? You know, I mean you you or [65:36] you you know, you can do these exercise [65:38] snacks. But I like to think of the the [65:40] things that you're talking about, you [65:41] know, walk to lunch instead of ordering [65:44] in. Mhm. You think that's not important [65:47] maybe. It's life-changing for some [65:49] people. It will literally change your [65:51] life if if you are doing very little and [65:54] you take that first step. [65:56] You know, it can change everything about [65:58] your, you know your future in some ways [66:02] because it builds the foundation for oh, [66:04] that feels good. Maybe I'll try a little [66:06] bit more, right? Maybe I'll try a little [66:08] bit more. You know, we're talking [66:09] earlier you were saying, you know, you [66:11] implement a new exercise regimen and you [66:12] jump in with everything and then you end [66:14] up, you know, getting a Achilles tendon [66:16] injury or something like that. You know, [66:18] that's especially true of people who [66:19] don't exercise at all. And so, you know, [66:22] the best thing to do is to start slowly [66:24] and really start reaping those rewards [66:26] because that's the motivator. And so [66:28] yeah, I mean I think if you are [66:30] exercising a lot, you know, day that [66:32] gets away from you and you can't make it [66:34] to the gym, [66:35] I mean getting a little bit of vigorous [66:36] activity, going for a really brisk walk, [66:39] going up the stairs, doing some push up [66:41] I mean anything is going to give you a [66:43] little bit of benefit. [66:45] You know, these are really easy things [66:47] that we can implement into our lives. [66:50] Quick one from one of our sponsors. A [66:52] lot of you have asked me the question [66:53] about Huel over the years about where [66:56] Huel fits into your life. Is it the most [66:58] healthy choice one can make when they're [67:00] thinking about what their nutrition. And [67:02] here's what I would say to all of those [67:04] people. I think in an ideal world, I [67:06] would be able to sit down and cook and [67:08] prepare all of my meals. I think that [67:10] would be my ideal option. But it because [67:12] of the nature of my life, because I'm [67:14] moving around often, what used to happen [67:16] before Huel was I'd end up making bad [67:19] choices. I'd end up snacking. I'd have [67:21] junk food options on the go because I [67:24] was busy and my nutrition would come [67:25] second to whatever my professional [67:27] priority was. What Huel allows you to do [67:29] is to have a healthier option on the go [67:31] that is convenient, that contains a lot [67:34] of the nutrients that you need to have a [67:35] complete diet. And that's exactly where [67:38] it fits in my life. They've now expanded [67:40] the range. If you haven't yet checked [67:41] out the Huel RTD, I highly recommend you [67:43] do. Go to your local Tesco, Boots or [67:45] Sainsbury's or online and you can grab [67:48] and try one there. [67:50] Does Alzheimer's exist on a spectrum, [67:52] per se? And is is what one end of that [67:55] spectrum sort of just general cognitive [67:57] decline and memory reduction? Cuz I [67:59] sometimes wonder obviously my job here [68:01] is to I interview very intelligent [68:03] people and those people come in all [68:05] shapes, sizes and ages. [68:07] And I obviously, as an observer [68:10] notice how some of the older people that [68:14] I meet [68:15] are incredibly [68:17] sharp. [68:19] You know, arguably significantly sharper [68:21] than I am. And I'm, you know [68:23] in some cases [68:25] 30% 40% of their age 40% of their age [68:28] and they're just unbelievably sharp. And [68:30] then we've also all had experiences [68:32] maybe with an older relative or you [68:33] know, someone slightly older where you [68:35] can see that [68:37] that their memory recall or their sort [68:39] of it's almost sometimes you experience [68:41] as their self-awareness has started to [68:43] wane. They might tell you [68:46] a short story in 1 hour, if you know [68:48] what I'm saying. They might they just [68:50] it's almost like the self-awareness of [68:51] what they're saying and how they're [68:52] saying it and their ability to [68:53] articulate themselves is some somewhat [68:55] slipped away. And I wonder if that [68:57] exists on the scale of dementia or [68:59] whether that's just general atrophy as [69:01] you call it of the brain. [69:02] Right. And I don't I really really want [69:04] to be someone, as I'm sure we all do [69:07] that has my brain works until the day [69:09] that I die. Yeah. You know. Yeah. We all [69:12] want that. Yeah, we all want that. Of [69:13] course. And I that's why I wonder if [69:15] it's the spectrum or is it is a [69:17] spectrum. [69:17] Yeah, I mean so there's sort of [69:19] a normal amount of cognitive change that [69:22] happens with aging in in most people [69:25] that in general should not impact your [69:27] daily life greatly, right? You should [69:29] still be able to do all the things you [69:31] want to do, navigate your world in the [69:33] way that you want to. You may have some, [69:35] you know, it's inevitable that there [69:37] will be some memory changes, [69:39] some changes in your in your executive [69:41] functions, planning, but not the kinds [69:44] of profound changes that we see in [69:46] people with dementia. And so dementia is [69:49] is is cognitive decline that impacts [69:51] your daily life in in a way that makes [69:53] it hard to keep doing the things you [69:55] want to do. [69:56] When you start to get down into sort of [69:59] the nitty-gritty of different types of [70:01] dementia, you know, Alzheimer's disease, [70:03] which is by far the most common, has a [70:05] lot of pathological features that make [70:07] it a progressive disease, right? That [70:09] that mean, you know, you will continue [70:11] to decline [70:13] over over the course of the disease and [70:14] there's no way to stop it really that we [70:16] know of. But there is going to be [70:18] there's always going to be some change [70:19] in your brain with age that you can't [70:21] fully stop for most people. I've also [70:23] always wondered about this is totally [70:24] random, but [70:26] I said this a few times to a few people, [70:27] this idea that when [70:29] a spouse or a partner passes away, [70:32] people seem to go into pretty quick [70:34] cognitive decline and their sort of [70:36] mortality risk seems to multiply. And [70:38] that could be a very complex thing to do [70:40] with cortisol and other things going on [70:41] in the body and hormones and [70:43] but I wondered if there was accelerated [70:45] atrophy if my if I'm 85 and my wife [70:47] passes away. Yeah, so I mean a couple [70:50] things are going on. Grief in itself is [70:52] associated with brain changes. There's [70:55] been interesting work on that. [70:56] Brain changes? Yeah, I mean that that [70:58] there are cognitive changes and and [70:59] structural changes that happen when [71:01] you're grieving. I think some of this is [71:03] depression as well, that's clear. And [71:05] one of the things, you know, untreated [71:08] depression can start to look a lot like [71:10] dementia. It's a risk factor for [71:12] dementia, but it can also look like [71:13] dementia because when you're undergoing [71:17] depression, a lot of things happen. You [71:19] stop paying attention when you're [71:20] talking to people. You're you're you're [71:22] you're not as present. And so you know, [71:25] what can sometimes seem like a memory [71:27] deficit might be because you weren't [71:29] paying able to pay attention to what was [71:31] going on in the first place. And so I [71:33] think one of the things that I worry [71:35] about with older adults a lot is making [71:37] sure that depression is treated because [71:39] especially when there are cognitive [71:42] challenges that they're that they're [71:44] experiencing, they're they're feeling [71:45] like they're [71:47] have declines in their thinking and [71:48] memory skills, [71:50] making sure they're not depressed is the [71:51] first step because you can treat that. [71:53] And actually you can treat that really [71:54] well with exercise. So you might be able [71:56] to get a couple of bangs for your buck [71:58] by both treating your, you know, helping [72:00] to manage your depressive symptoms and [72:02] getting the brain other brain benefits. [72:04] But you can also treat it [72:05] pharmaceutically [72:06] or with therapy and that can have a [72:08] profound impact on the way that you [72:10] think and the way that you manage [72:13] those symptoms. So, yeah, I think losing [72:15] a partner, you're also losing a social [72:17] connection and we know that social [72:19] connections are so important. And so [72:21] that loneliness and that loss of a [72:22] social connection is important. So, [72:24] I think that's that's all wrapped up in [72:27] these brain changes and these are all [72:28] modifiable things. We can watch out for [72:31] our parents or people in our community [72:33] when these are hap things are happening [72:35] and try to help them maintain better [72:37] social connections. [72:39] We have a closing tradition on this [72:40] podcast where the last guest leaves a [72:41] question for the next guest. Unaware of [72:43] who they'll be leaving it for. And the [72:45] question left for you, interesting, [72:47] maybe a little bit obvious, but [72:49] how can your work help the world? [72:53] It's a simple answer, I guess, but I [72:55] think it's profound that if you if you [72:58] sit less and you move more, you will not [73:01] only help yourself, but you will also [73:03] help the general population, right? I [73:06] mean we when when we talk about um [73:09] aging, [73:11] it doesn't just affect you, right? It [73:13] affects everybody around you, it affects [73:16] your family, caregivers, it affects our [73:18] economy. I mean, the US is is is is [73:23] we're thinking the US might end up [73:25] spending a trillion dollars a year on [73:27] Alzheimer's disease by 2050, right? And [73:30] so prevention will have a big impact on [73:33] our economy. And I'm not saying people [73:34] should implement sitting less and moving [73:36] more for our economy, but by doing that [73:39] you might actually on a broad scale have [73:41] a big impact on on our world. And so, [73:45] you know, I hope that that message gets [73:46] out there. That's why I'm so I was [73:48] excited to, you know, to do this podcast [73:50] with you because, you know, I think it [73:52] is a message that we need to keep [73:54] repeating and and and find ways to help [73:56] people do that because I think it can [73:57] have a profound effect on themselves, [74:00] their family, and society. Are you [74:02] hopeful? [74:03] Well, that's a hard question to answer. [74:06] I mean, I I am on some level because I [74:09] think, you know, especially with the [74:10] focus on, you know, start moving away [74:13] from having people do big steps and [74:15] trying to get people to do small steps [74:17] first, I am hopeful that we can motivate [74:19] people to to implement these these [74:21] changes. I I hope it's possible. [74:25] It's been hard to do. [74:25] Is the the data going in the wrong [74:27] direction at the moment? [74:29] Generally? You know, what we just [74:30] haven't seen big improvements in in [74:32] adherence and I think one of the things [74:34] I'm worried about is that worldwide [74:38] more countries are becoming more like [74:41] the US and UK and instead of less, [74:43] right? And our societies are aging. And [74:46] so, you know, we have a larger number of [74:48] older people and so just by the sheer [74:51] numbers, we're going to have more people [74:52] with these these diseases. And so, you [74:55] know, [74:57] implementing these these [74:59] increases in activity, reductions in [75:01] sedentary behavior, hopefully will have [75:04] these kind of profound effects on our [75:05] aging society, but I think it needs to [75:08] be our focus. Like right now, you know, [75:10] when we think about Alzheimer's disease, [75:12] we don't have drugs that that are going [75:13] to have a big impact. I mean, there's [75:15] some new drugs that that are promising [75:17] maybe, [75:18] um but the biggest thing we can do is [75:19] prevention. And that's where this work [75:22] comes in is, you know, if we can prevent [75:24] or delay, [75:25] we can save people happiness, I mean, [75:28] improve their happiness and we can save [75:30] money and we can improve society. David, [75:32] thank you. Thank you. Absolutely [75:34] incredibly enlightening and inspiring [75:36] and may maybe most importantly of all, [75:38] motivating conversation. Motivating [75:40] because knowledge is power [75:43] and you've given me so much knowledge [75:45] which has added fuel to a bunch of [75:48] different behaviors that are critical [75:50] for my cognitive outcomes, but also just [75:52] my overall day-to-day health. So, thank [75:54] you so much for that. Thank you so much [75:56] for doing the work that you do because I [75:58] know you're probably doing it in part [76:00] because you're incredibly curious and [76:01] you love it, [76:02] but the other part of that is it's an [76:04] incredible service to all of us that you [76:06] go out there and you take this time to [76:08] do all this research that you then pass [76:10] out to society in a way that's going to [76:12] serve us and get us close to the goals [76:13] that matter most, keep us healthy and [76:15] happy into our later years and keep [76:18] families together ultimately. So, thank [76:19] you for the work you do and thank you [76:20] for being here today. You're welcome. [76:21] Thanks so much for having me on. It's [76:23] been a pleasure. [76:25] Quick one. As you might know, a company [76:27] that I have invested in is now also a [76:29] sponsor of this podcast and they're [76:30] called Zoe. And I'm coming to you today [76:33] with a warning. It is January and it's [76:35] all of those diet companies' favorite [76:37] month of the year and that means that [76:39] you're about to hear a lot of jargon and [76:41] words across all types of media when it [76:44] comes to diet culture. Please don't get [76:46] caught up in the fads. When it comes to [76:48] your own health, you must listen to [76:51] experts and that's exactly what Zoe has. [76:53] Zoe isn't about restriction or removing [76:56] foods from your diet, it's about [76:57] building sustainable daily habits that [77:00] will make your life better forever. [77:02] They'll help you to discover how eating [77:04] in the right way for your body with what [77:07] they call personalized nutrition will [77:09] have you feeling the benefits almost [77:10] instantly and far into the future. If [77:13] you're looking to pick up new habits [77:14] this year, then use my code CEO10 [77:18] to get 10% off of your Zoe kit and do it [77:21] right now. [77:23] Do you need a podcast to listen to next? [77:26] We've discovered that people who liked [77:27] this episode also tend to absolutely [77:30] love another recent episode we've done. [77:32] So I've linked that episode in the [77:34] description below. I know you'll enjoy [77:36] it. [77:42] [Music]