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昼夜节律对健康的影响

主题是解释昼夜节律（circadian rhythm）的定义、重要性，以及当其失调时对身体的影响。内容涵盖昼夜节律的基本概念、失调的后果、测量方法、优化建议，以及对夜班工作者、饮食时间、运动和光照等具体场景的指导。

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什么是昼夜节律？

昼夜节律是指持续约24小时的生物节律，控制人体多项生理活动。常见例子包括睡眠-活动周期和禁食-进食周期，这些节律与昼夜光暗周期密切相关。当睡眠、活动、进食和乏食与光暗周期对齐时，昼夜节律处于“同步”状态。失调（out of sync）则指这些节律与外部环境（如光照）或内部器官时钟不一致，例如因时差或夜班工作导致的混乱。

昼夜节律远不止睡眠和清醒。体内几乎每个基因、激素、脑化学物质和消化系统都以特定时间升降。例如：

• 晨间活动：清晨排便较常见，早餐时摄入大量碳水化合物不易导致血糖骤升。
• 激素变化：清晨皮质醇（压力激素）上升，帮助唤醒时精力充沛；睡前2-3小时褪黑素上升，促进入睡。
• 身体协调：白天心率和体温升高，适合活动和进食；夜间则适合修复，如线粒体夜间修复以提高白天效率。

昼夜节律的作用

昼夜节律有三大功能：

1. 时间预期：帮助身体提前准备，如清晨皮质醇上升预备清醒，睡前褪黑素上升预备睡眠。
2. 同步协调：确保相关功能协同，例如白天活跃时感到饥饿，细胞内线粒体白天高效工作。
3. 功能分离：避免冲突过程同时发生，如夜间不宜排便，氧化损伤和修复酶活动时间错开以防DNA损伤。

昼夜节律失调的后果

当昼夜节律失调时，身体和心理健康可能受损。短期失调（如时差）会导致：

• jet lag（时差反应）：大脑仍跟随旧时区，感到白天嗜睡，身体却需适应新时区，降低生产力，增加焦虑和压力。

长期失调（如夜班工作或不规律作息）则风险更高，可能导致：

• 糖尿病、肥胖、心血管疾病、高血压、高胆固醇。
• 儿童可能出现ADHD（注意力缺陷多动症）或ASD（自闭症谱系障碍）。
• 老年人可能增加痴呆和癌症风险。

即使日常生活中轻微失调（如晚睡或晚餐时间不规律），也可能引发症状：

• 女性可能出现月经不调或停经。
• 肠易激综合征（如排便频繁）。
• 注意力难以集中。
• 50%成年人可能出现前驱糖尿病，部分原因可能与节律失调相关。研究显示，健康年轻人每晚睡眠从7-8小时减少至5小时，一周内即可出现前驱糖尿病症状。

测量昼夜节律是否失调

目前没有简单可用的生物标志物供普通人检测昼夜节律，因为：

• 节律需多次采样（如一天内多次测量）才能判断正常与否。
• 不同器官（如大脑、肠道、肝脏）有各自的昼夜时钟，需分别追踪。
• 激素如皮质醇虽有昼夜模式（晨高晚低），但受压力等外部因素干扰，难以准确反映节律。
• 褪黑素是较稳定的指标，但白天水平极低，仅睡前上升，需夜间多次采样，且仅反映大脑节律，无法代表其他器官。

因此，普通人可通过症状观察失调迹象，如月经不调、肠道问题或注意力下降。若怀疑失调，建议调整睡眠、进食和光照时间，观察症状是否改善。

睡眠时段与质量

睡眠时段（circadian timing）与睡眠时长和质量同等重要。例如：

• 若每晚2点睡、10点起，睡眠8小时且环境安静（如无噪音、空调适宜），质量可能良好，相当于生活在不同时区。但若需早起工作或有干扰，晚睡可能导致睡眠不足。
• 现代生活（如照顾孩子或工作）常使晚睡难以保证足够睡眠时长，建议提前入睡时间，确保8小时在床时间，避免依赖闹钟多次“贪睡”。

睡眠不仅是昼夜节律的一部分，还负责脑部“清洁”。夜间神经元同步活动，产生波浪清洗脑内“毒素”（代谢废物），类似洗衣机的洗涤干燥周期。若睡眠不足，相当于穿上未洗净的衣服，需靠咖啡提神，这表明大脑未充分恢复。

光照对昼夜节律的影响

光照是昼夜节律的主要“校准器”。人体内部时钟并非精确24小时（约24小时15-30分钟），需每日通过光照重置。关键点：

• 晨光和晚光：清晨或傍晚光照（尤其日出日落后）对重置大脑时钟最有效，白天光照则主要提升情绪。
• 光照作用：
  • 晨光同步大脑与昼夜周期，缓解时差，提升警觉性。
  • 日光通过视网膜约5000个神经元作用，与维生素D合成无关，补充维生素D无法替代光照。
  • 日光是天然抗抑郁剂，80%人一生中至少经历一次抑郁或焦虑，户外光照可缓解低落情绪。
• 获取光照：
  • 即使在温哥华或伦敦的阴雨天，户外仍可获得4000-5000勒克斯光照，远超所需1000勒克斯。
  • 室内需靠近大窗户（1米内），因光强随距离急剧下降。
  • 若无法获取自然光，可用5000-10000勒克斯的模拟日光灯，特别是在北欧等冬季光照不足地区。

夜班工作者的应对策略

夜班工作者（如医护人员、警察）因工作时间颠倒，难以获取自然光，昼夜节律易失调。

一位圣地亚哥警察的经验：无论何时下班，每天在日落前醒来一小时，户外获取阳光，称其为“能量秘诀”。

建议：

• 光照替代：使用模拟日光灯（5000-10000勒克斯）或蓝光LED眼镜（约250美元），蓝光对提升警觉性、减少抑郁和重置时钟最有效。美国军方和运动员也用此类设备缓解时差。
• 技术创新需求：目前模拟日光灯泡昂贵（超1000美元），呼吁开发10美元以下的平价灯泡，改善夜班工作者生活。
• 注意事项：避免直视强光以防头痛，未亲自测试产品，不作推荐。

饮食与昼夜节律

饮食时间显著影响昼夜节律，开创“限时进食”研究。关键发现：

• 进食窗口：将每日进食控制在8-10小时内（最多12小时），剩余时间不吃（14小时为佳），可改善睡眠、代谢、炎症和心理表现。
• 晚餐影响：
  • 晚餐过晚（睡前2小时内）导致餐后体温升高，干扰入睡（入睡需体温降低）。
  • 褪黑素睡前2-3小时上升，使胰腺“休息”，晚餐碳水化合物摄入可能导致血糖偏高，长期增加前驱糖尿病和体重风险。
  • 晚餐常伴甜点和酒精，增加不健康摄入。
• 最佳进食时间：
  • 早餐后1-2小时进食，避免皮质醇和褪黑素干扰血糖调节。
  • 晚餐至少睡前2-3小时结束，理想为傍晚6-7点。
  • 尽管人体傍晚更饥饿，晚餐不宜过大，需平衡社会习惯（如晚餐为主餐）与健康需求。
• 夜班工作者：8-10小时进食窗口可帮助维持身心表现，改善睡眠质量。

长时间乏食的影响

未研究多日乏食（如3-5天），因其适用人群有限。动物实验显示：

• 24小时以上乏食减弱小鼠昼夜节律，基因活动进入“维护模式”，减缓波动。
• 大脑主时钟节律不受乏食影响，保持稳定。
• 乏食第一天睡眠质量差（饥饿、头痛），第二三天适应，但乏食后进食时间（晨或午）对节律影响尚不清楚。

运动时间

下午晚些时候（而非清晨）运动更有益，原因：

• 生理状态：下午体温、血流、血压和肌肉灵活性较高，减少热身需求，降低受伤风险。
• 代谢优势：下午胰腺功能减弱，肌肉可独立于胰岛素吸收葡萄糖，运动有效降低血糖，优于晨练。
• 数据支持：NFL西海岸球队飞往东海岸比赛时，因下午比赛（相当于其体内时间）表现更佳，启发后续研究。
• 灵活性：任何时间运动均优于不运动，若时间有限，随时运动即可。

夜间排尿与肾脏节律

夜间频繁起夜（如1-2次）可能因肾脏节律与大脑节律不同步。例如，晚睡者（2点睡、10点起）可能在晨7-8点因肾脏活动醒来排尿。建议：

• 水分管理：睡前2-3小时避免大量饮水，改用小口啜饮，减少肾脏负担。
• 日间补水：白天保持充分水合，睡前3-4小时减少摄入。
• 个性化：肾脏节律受水摄入、血压调节和解毒功能影响，需因人调整。

褪黑素补充

褪黑素补充因人而异，效果和风险未完全研究：

• 剂量差异：1毫克对敏感者有效，部分人需15毫克。
• 潜在风险：
  • 高剂量（如5毫克）可能导致晨间褪黑素水平过高，干扰餐后血糖（抑制胰岛素释放），长期可能增加糖尿病风险。
  • 长期使用可能提高多巴胺需求或影响其他代谢（未充分验证）。
• 替代品：色氨酸（褪黑素前体）搭配健康碳水化合物可能更安全，但缺乏严谨研究支持。
• 建议：因研究不足，谨慎使用，避免长期高剂量。

现代习惯对昼夜节律的危害

现代生活方式常干扰昼夜节律，常见问题：

• 夜间科技使用：Netflix等数字平台鼓励熬夜，增加蓝光暴露，干扰褪黑素分泌，降低睡眠质量。
• 不规律作息：非9-5工作制（如24/7工作）导致睡眠和进食时间随机，放大健康风险。
• 营销驱动：广告和娱乐产业鼓励清醒时间延长，增加消费，牺牲睡眠。

其他影响因素

• 温度：人类历史上昼夜温差明显（白天高、夜间低），现代恒温环境可能干扰睡眠，高温尤其不利入睡。
• 社交互动：规律的家庭或朋友互动可部分校准节律，缓解压力，改善睡眠。

理想的昼夜节律一天

描述一个优化昼夜节律的理想日程，强调“一天始于前晚入睡”：

1. 前晚入睡：固定时间上床，确保8小时在床时间，促进脑部解毒、记忆存储和生长激素修复。
2. 早晨：

   * 醒后1-2小时再进食，避免皮质醇和褪黑素干扰血糖。

   * 户外获取晨光（1小时），重置大脑时钟，提升情绪。

3. 白天：

   * 固定早餐时间，校准身体时钟。

   * 8-12小时内完成所有进食（理想8-10小时），14小时不吃，优化代谢和睡眠。

   * 下午晚些时候运动（若时间允许），改善血糖和血压。

4. 傍晚：

   * 晚餐睡前2-3小时结束，避免食物和酒精。

   * 降低光照（调暗灯光），促进褪黑素分泌。

5. 夜间：无食物、无强光，确保安静黑暗环境，助眠。

资源与建议

主讲人推荐其书《The Circadian Code: Lose Weight, Supercharge Your Energy, and Transform Your Health from Morning to Midnight》及学术应用mycircadianclock.org，免费提供节律优化指导，分析用户饮食和睡眠习惯，保护数据隐私。建议关注症状、调整作息，优化健康。

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主题是解释昼夜节律是什么，为什么重要，以及失调时对身体的影响。昼夜节律是持续大约24小时的生物节律，控制睡眠、活动、进食和禁食等过程，这些都跟光暗周期相关。当这些节律跟白天黑夜对齐，就叫同步；如果不对齐，比如因为时差或夜班工作，就叫失调。昼夜节律不只是睡眠和清醒，身体里几乎每个基因、激素、脑化学物质、消化系统都在特定时间升降。比如早上容易排便，早餐吃碳水化合物不会让血糖飙得太高。清晨皮质醇会升，让你醒来有活力；睡前两三小时褪黑素升，帮你入睡。心率、体温白天升，夜间降，线粒体夜里修复，白天高效工作。

昼夜节律有几个作用：一是预期时间，比如皮质醇提前升让你早上精神，褪黑素提前升让你上床就能睡；二是同步相关功能，比如白天活跃时感到饿，细胞里线粒体白天更高效；三是分开不该同时发生的事，比如夜里不该排便，氧化损伤和修复酶时间错开，避免DNA损伤。失调会有很多后果。短期像时差，脑子还跟着旧时区，白天想睡，但身体得适应新时区，效率低，焦虑压力大。长期失调，比如夜班或不规律作息，可能导致糖尿病、肥胖、心血管病、高血压、高胆固醇，甚至小孩可能得ADHD或自闭症，老年人可能增加痴呆和癌症风险。即使日常轻微失调，比如晚睡或晚餐时间乱，女性可能月经不调，或者有肠易激问题，注意力下降。研究说50%的成年人可能有前驱糖尿病，部分原因可能跟节律失调有关。健康年轻人每晚睡5小时而不是7-8小时，一周就可能出现前驱糖尿病症状。

想知道节律是否失调，目前没简单的生物标志物给普通人用。因为节律需要多次采样才能判断正常，大脑、肠道、肝脏这些器官都有自己的时钟，得分别测。皮质醇早上高晚上低，但压力会干扰它，测不准。褪黑素稳定点，但白天几乎测不到，只睡前升，夜里得多次采样，还只能反映大脑的节律，不是全身。所以得靠症状看，比如月经不调、肠道问题、注意力差，调整睡眠、进食、光照时间，看症状能不能好。

睡眠时段跟时长、质量一样重要。比如每晚2点睡10点起，睡8小时，环境安静，质量可能好，相当于活在另一个时区。但如果得早起工作或有干扰，晚睡就可能睡不够。现代生活，比如带小孩或工作，晚睡常导致睡眠不足，建议早点睡，保证8小时在床时间，别老按闹钟“贪睡”。睡眠不只是节律一部分，还负责脑子“洗澡”。夜里神经元一起活动，产生波浪清掉代谢废物，像洗衣机洗涤干燥。睡不够就像穿没洗干净的衣服，靠咖啡提神，说明脑子没恢复好。

光照是校准节律的关键。人体时钟不精确是24小时，大概24小时15-30分钟，每天得靠光重置。早上和傍晚光照，特别日出日落后，最能重置大脑时钟，白天的光主要提情绪。晨光让大脑跟昼夜同步，缓解时差，增加警觉。日光通过视网膜5000个神经元起作用，跟维生素D没关系，补维生素D代替不了光照。日光是最好的抗抑郁剂，80%的人一生至少有一次抑郁或焦虑，户外光能缓解低落情绪。即使温哥华或伦敦阴雨天，户外也有4000-5000勒克斯光照，远超需要的1000勒克斯。室内得靠大窗户1米内，光强远了就弱。没自然光可以用5000-10000勒克斯的模拟日光灯，北欧常用。

夜班工作者，比如医护、警察，工作时间反转，难有自然光，节律容易乱。主讲人讲了个圣地亚哥警察的经验，不管啥时下班，每天日落前醒一小时，户外晒太阳，觉得那是“能量秘诀”。建议用5000-10000勒克斯的模拟日光灯或蓝光LED眼镜，蓝光提警觉、减抑郁、重置时钟效果最好，价格约250美元。美国军队和运动员也用这个缓解时差。模拟日光灯泡现在贵，超1000美元，主讲人希望有10美元的平价灯泡，改善夜班工作者生活。强光别直视，防头痛，主讲人没测试产品，不随便推荐。

饮食时间影响节律，主讲人实验室开创了时间限制性进食，学术版的间歇性禁食。每天进食控制在8-10小时，最多12小时，禁食14小时最好，能改善睡眠、代谢、炎症、心理表现。晚餐太晚，睡前2小时内，餐后体温高，干扰入睡，因为入睡得体温低。褪黑素睡前2-3小时升，让胰腺“休息”，晚餐碳水可能血糖高，长期增前驱糖尿病和体重风险。晚餐还常有甜点酒精，增加不健康摄入。建议醒后1-2小时再吃早餐，避开皮质醇和褪黑素干扰血糖，晚餐睡前2-3小时结束，最好傍晚6-7点。人体傍晚更饿，但晚餐别太大，得平衡社会习惯和健康。夜班工作者用8-10小时进食窗口，能保持身心表现，睡得更好。

主讲人不研究多日禁食，比如3-5天，因适用人群少。小鼠实验说24小时以上禁食会减弱节律，基因活动变“维护模式”，慢下来。大脑主时钟不受禁食影响，一直稳。禁食第一天睡不好，饿、头痛，第二三天适应，但断食后吃的时间对节律影响还不清楚。

下午晚些时候运动比清晨好，下午体温、血流、血压、肌肉灵活性高，热身少，伤风险低。胰腺下午功能弱，肌肉可不靠胰岛素吸葡萄糖，运动降血糖比早上好。NFL西海岸队飞东海岸比赛，下午比赛相当于体内时间，胜率稍高，启发研究。任何时间运动都比不运动好，没时间就随时动。

夜里老起夜排尿，比如1-2次，可能肾脏节律跟大脑不同步。晚睡2点起10点的，晨7-8点可能因肾脏活动醒来尿尿。建议睡前2-3小时别喝太多水，改小口啜饮，白天多补水，睡前3-4小时少喝。肾脏节律还管血压、解毒，需个性化调整。

褪黑素补充因人而异，研究不全。有人1毫克就睡着，有人要15毫克。高剂量像5毫克，早上褪黑素可能还高，干扰血糖，长期可能增糖尿病风险。长期用可能提高多巴胺需求，没完全验证。色氨酸加健康碳水可能更安全，但没严谨研究。建议谨慎，别长期高剂量。

现代习惯伤节律。Netflix等数字平台鼓励熬夜，蓝光干扰褪黑素，睡不好。非9-5工作让睡眠进食时间乱，加重健康风险。广告娱乐想让你清醒消费，牺牲睡眠。温度也影响，人类历史昼夜温差大，现在恒温可能扰睡眠，高温特别难入睡。社交互动能校准节律，定期家庭朋友时间减压，睡更好。

理想一天从前晚入睡开始。固定时间上床，8小时在床，脑子解毒、存记忆、修身体。醒后1-2小时再吃早餐，避血糖问题。户外晒1小时晨光，重置时钟，提情绪。早餐时间固定，校准身体时钟，8-10小时吃完所有食物，禁食14小时，改善代谢睡眠。下午晚些时候运动，降血糖血压。晚餐睡前2-3小时结束，傍晚6-7点最好。睡前调暗光，无食物，攒褪黑素，睡好觉。

主讲人推荐书《The Circadian Code》，还有免费学术应用mycircadianclock.org，分析饮食睡眠习惯，指导优化节律，不卖数据。建议关注症状，调作息，改善健康。

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我研究昼夜节律及其对人体健康的影响。昼夜节律是指人体内持续约一天的节律，包括睡眠-活动节律和禁食-进食节律。这三者需要与昼夜或明暗循环保持一致，才能使身体处于最佳状态。 昼夜节律紊乱会导致多种负面影响，从短期内的低效、焦虑到长期内的慢性疾病风险增加，例如糖尿病、肥胖、心血管疾病等。 目前没有简单的生物标记物可以用于日常生活中评估昼夜节律是否紊乱，因为昼夜节律涉及多个器官和系统。但是，我们可以通过一些症状来判断，例如月经不调、肠易激综合征、注意力不集中以及代谢问题。 睡眠时间和睡眠时间安排同等重要，需要根据个人情况进行权衡。保持一致的睡眠时间安排比睡眠时间长短更重要，但需要根据个人情况和生活方式进行调整。充足的睡眠对于大脑的清洁和修复至关重要。 早晨接触明亮的自然光线对于调节昼夜节律至关重要，因为它可以重置生物钟并改善情绪。即使在阴天，靠近窗户也能获得足够的日光照射。 夜班工作者可以通过在日落前接触日光或人造光来重置昼夜节律。补充维生素D并不能替代日光照射来调节昼夜节律。可以通过补觉来弥补睡眠不足，这与昼夜节律调节不同。 现代人常见的损害睡眠质量的习惯包括长时间使用电子设备、工作压力大以及饮食不规律。时间限制性饮食（TRE）可以改善睡眠质量和整体健康状况，即使对于轮班工作者也是如此。 睡前吃东西会影响睡眠质量，因为消化过程会升高体温并干扰褪黑素的分泌。补充褪黑素可能存在潜在风险，需要谨慎使用并注意剂量。长期禁食可能会抑制昼夜节律，但其对睡眠的影响需要进一步研究。 睡前饮水过多会导致夜间起夜，建议在睡前几小时减少饮水量。一天中大部分生理活动在白天进行得更好，建议将大部分活动安排在白天，晚上则应逐渐放松。下午或傍晚锻炼比早晨锻炼更有益于身体健康和运动表现。 除了饮食、运动、光照和睡眠之外，环境温度和社交互动也对昼夜节律和健康有影响。理想的昼夜节律生活方式包括规律的睡眠时间、一致的进食时间、充足的日照和适当的运动。

昼夜节律，顾名思义，是指人体内大约24小时的生物节律，它协调着我们的睡眠-觉醒周期和进食-禁食周期。这两种节律与昼夜（或明暗）循环的同步至关重要，是维持身心健康的基石。

昼夜节律紊乱的后果不容忽视。轻则导致效率低下、焦虑不安，重则增加患上慢性疾病的风险，例如糖尿病、肥胖症和心血管疾病等。长期紊乱甚至可能与ADHD、ASD（儿童）、痴呆症和癌症（老年人）等疾病相关。

遗憾的是，目前尚无简单易行的生物标记物来评估日常生活中昼夜节律的紊乱程度。因为昼夜节律是一个复杂的系统，它涉及到我们身体的几乎每一个器官和细胞。然而，一些症状可以提示昼夜节律的紊乱，例如女性月经不调、肠易激综合征、注意力难以集中以及血糖代谢异常等。

睡眠时间与睡眠规律同样重要。 虽然充足的睡眠至关重要，但保持规律的睡眠时间安排可能比单纯追求睡眠时长更为关键。 这就好比给大脑进行每日的“清洁和维护”，如果睡眠不足或睡眠质量差，就如同让大脑穿着“脏衣服”开始新的一天，自然会感到疲惫和效率低下。

早晨的阳光是生物钟的“重置按钮”。 明亮的自然光线，特别是早晨的阳光，对于调节昼夜节律至关重要，能有效地重置生物钟，并提升情绪，改善抑郁症状。即使在阴雨天，靠近窗户也能获得足够的日光照射，达到类似效果。

夜班工作者的昼夜节律调节策略： 对于夜班工作者来说，在日落前尽可能地接触自然光线，或使用模拟日光的人造光源，是重置生物钟的关键。 补充维生素D并不能替代日光照射的作用，因为维生素D的合成途径与昼夜节律的调节机制并不相同。 睡眠不足可以通过补觉来弥补，但这与昼夜节律的长期调节是不同的概念。

现代生活中的睡眠杀手： 现代社会中，许多因素都会扰乱昼夜节律，例如长时间使用电子设备（蓝光）、巨大的工作压力以及不规律的饮食习惯。限时进食，即在相对较短的时间窗口内进食，已被证明可以改善睡眠质量和整体健康状况，即使对于轮班工作者也同样有效。

睡前饮食与睡眠质量： 睡前进食会影响睡眠质量。这是因为消化过程会升高体温，干扰褪黑素的分泌，而褪黑素是调节睡眠的重要激素。 虽然补充褪黑素可以帮助入睡，但长期服用可能存在潜在风险，建议谨慎使用并咨询医生，确定合适的剂量。 关于长期乏食对昼夜节律的影响，目前的研究还相对有限，需要进一步探索。

控制夜间起夜： 睡前饮水过多会导致夜间频繁起夜。建议在睡前三到四个小时减少饮水量，或者改成少量多次饮水（啜饮）。 需要注意的是，夜间起夜也可能与肾脏的昼夜节律有关，这需要根据个人情况进行调整。

一天中最佳活动时间： 我们的身体在白天运作效率更高。因此，建议将大部分精力充沛的活动安排在白天，而晚上则应逐渐放松身心，为睡眠做好准备。 下午或傍晚进行锻炼，比早晨锻炼更有利于提升运动表现，并更好地调节血糖和血压。

被忽视的昼夜节律调节因素： 除了饮食、运动、光照和睡眠之外，环境温度和社交互动也对昼夜节律和整体健康产生影响。 长期处于恒温环境中可能会扰乱我们的生物节律，而规律的社交活动则有助于缓解压力，改善睡眠质量。

理想的昼夜节律生活方式： 总结来说，理想的昼夜节律生活方式包括：规律的睡眠时间（保证8小时睡眠时间）、一致的进食时间（控制在8-12小时的进食窗口）、充足的日照（尤其在早晨）、适当的运动（建议在下午或傍晚）。 记住，调节昼夜节律是一个循序渐进的过程，需要耐心和坚持。 通过调整生活方式，可以更好地与自身的生物钟和谐相处，从而获得更健康、更长寿的生活。

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00:27 人体内的昼夜节律是指持续约一天的节律，包括睡眠-活动节律和禁食-进食节律，这三者需要与昼夜或明暗循环保持一致。

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01:42 昼夜节律对人体至关重要，它帮助我们预测时间，同步各种生理活动，并分离不相容的活动。

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04:49 昼夜节律紊乱会导致多种负面影响，从短期内的低效、焦虑到长期内的慢性疾病风险增加。

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06:57 目前没有简单的生物标记物可以用于日常生活中评估昼夜节律是否紊乱，因为昼夜节律涉及多个器官和系统。

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09:23 昼夜节律紊乱的症状因人而异，可能包括月经不调、肠易激综合征、注意力不集中以及代谢问题。

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12:16 睡眠时间和睡眠时间安排同等重要，需要根据个人情况进行权衡。

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16:33 保持一致的睡眠时间安排比睡眠时间长短更重要，但需要根据个人情况和生活方式进行调整。

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19:03 早晨接触明亮的自然光线对于调节昼夜节律至关重要，因为它可以重置生物钟并改善情绪。

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24:59 夜班工作者可以通过在日落前接触日光或人造光来重置昼夜节律。

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30:27 补充维生素D并不能替代日光照射来调节昼夜节律。

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31:50 可以通过补觉来弥补睡眠不足，这与昼夜节律调节不同。

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34:59 现代人常见的损害睡眠质量的习惯包括长时间使用电子设备、工作压力大以及饮食不规律。

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37:14 时间限制性饮食（TRE）可以改善睡眠质量和整体健康状况，即使对于轮班工作者也是如此。

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40:57 睡前吃东西会影响睡眠质量，因为消化过程会升高体温并干扰褪黑素的分泌。

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43:07 补充褪黑素可能存在潜在风险，需要谨慎使用并注意剂量。

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45:54 长期禁食可能会抑制昼夜节律，但其对睡眠的影响需要进一步研究。

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51:22 睡前饮水过多会导致夜间起夜，建议在睡前几小时减少饮水量。

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56:04 一天中大部分生理活动在白天进行得更好，建议将大部分活动安排在白天，晚上则应逐渐放松。

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56:32 下午或傍晚锻炼比早晨锻炼更有益于身体健康和运动表现。

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59:31 除了饮食、运动、光照和睡眠之外，环境温度和社交互动也对昼夜节律和健康有影响。

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01:01:45 理想的昼夜节律生活方式包括规律的睡眠时间、一致的进食时间、充足的日照和适当的运动。

00:00

So the first question for you is, what happens in our bodies when our circadian rhythm is out of sync? Yeah, so there are quite a few things that you asked. What is circadian rhythm? What is being in sync? And what is out of sync? So let me break it down. So circadian rhythm, so the word itself means rhythms that last about a day. 语法解析

00:27

So then the first thing that comes to your mind is sleep. But the opposite of sleep is not being just awake, sleep and activity. And then when we sleep, we also tend to not eat, most of us, unless you wake up in the middle of the night and eat. So that's a different thing. But typically people don't eat. So then there is the fasting and feeding or eating cycle. So these two are 语法解析

00:51

sleep activity rhythm and fasting and eating rhythm and that connection to day and night cycle because there is a strong day. So these three have to be in certain alignment and I'll go over that. And that's when we say that, okay, so your rhythms are in sync. So you're 语法解析

01:14

eating, fasting, sleep, and activity rhythms are in alignment with the day and night or light-dark cycle. So then the question is, what does, why do we need these rhythms? These rhythms, well, the sleep-wake or sleep activity is kind of the tip of the iceberg, and you see only a tiny part of the iceberg when it is above water. So similarly, there are 语法解析

01:42

lot of things that cycle in our body and if you pay a little bit more attention to your daily activity and lifestyle or rhythms you will see that you are more likely to have bowel movement in the morning not in the middle of your night and similarly your hormone profiles change so you're more 语法解析

02:00

likely to consume a large meal with carbohydrate without spiking your glucose dangerously high in the first half of the day than in the second half of the day or late in the evening. So similarly, if we dive deep, then we find that almost every gene, every hormone, every brain chemical, digestive system, everything changes. 语法解析

02:23

rises and falls at a certain time of the day or night. And these rhythms help us to do a few things. One is the anticipate time. For example, in the morning, anticipating waking up, your stress hormone level cortisol begins to rise so that when you wake up, you feel more energetic. 语法解析

02:42

Similarly, anticipating going to bed, your melatonin rhythms begin to rise two to three hours before going to bed so that as soon as you hit the bed, within a few minutes you can fall asleep. So similarly, there are many things that happen in anticipation. Your heart rate goes up, your body temperature goes up or down. Second thing is it synchronizes different things that should work together. For example, 语法解析

03:08

During daytime, you have to be more active and you should feel hungry. So those two things should go together. Similarly, at every level in the cell, for example, your mitochondria should be repaired at night and should be really humming and working more efficiently during daytime. 语法解析

03:28

when you are eating. So starting from single cell to whole animal or whole body, there are many things that should go together, should happen together. And the third thing is circadian rhythms also separate things that don't go together. So for example, on a big picture, 语法解析

03:48

Your bowel movement should not happen in the middle of your night, middle of the night when you're sleeping. And so that is one example. Similarly, there are a lot of examples where the oxidative damage that happens to our body or to every single cell and the repair enzymes that naturally clenches the oxidative radicals that happen at the same time so that we don't build up too much 语法解析

04:19

reactive oxygen species or we don't damage our DNA and other stuff. So these are some of the benefits. So then you asked, how do we know or what happens when these are out of sync? So it's always easy to define what is out of sync because, for example, if you travel across 10, 12 time zones, then for the first one or two days, you feel jet lagged. That means your brain is still in the old time zone. It's still feeling sleepy. 语法解析

04:49

During the day, it's not in sync with the local time and your body, since you have to get up, walk, go to some places, meet friends or do your business, your muscle and your body is actually in the new time zone. So there is this sync out of sync that happens and that reduces productivity significantly. 语法解析

05:10

increases anxiety and distress if it is short term, but if it continues for many months or years, for example, if you are working the lifestyle of a shift worker where 语法解析

05:23

for say you work very late into the night almost every single day and then on Saturday, Sunday you are catching up and you are kind of coming back to regular life, then that can also put distress on your body and mind so that increases risk for diabetes, obesity, cardiovascular disease, high blood pressure for example, high cholesterol and even ADHD, ASD for young children to dementia and cancer for older adults. 语法解析

05:53

Yeah, I mean, I think the example you brought up in the jet lag where you travel from, let's say, an Eastern time zone to Asia time zone, where it's literally day and night are obvious for the brain to think that you're in a different time zone. So you feel tired, groggy, not able to think. But for everyday people that just 语法解析

06:15

don't travel, but perhaps they sleep a little bit later or their circadian rhythm is just a little bit out of sync because they eat. They're used to eating a little bit later. What are some of the other measurements, if there are any, like, let's say, is there a way to have any biomarker measurements to get a clearer understanding to see if your circadian rhythm is a little bit out of sync? 语法解析

06:42

Yeah, it's actually everybody wants to have a biomarker these days and unfortunately there is none that everyday people can use because you know we are talking about rhythms. So that means you have to take multiple samples. 语法解析

06:57

to come up with a marker saying that this is normal or this is abnormal. And another thing is, it's not that your body is in sync with outside world, but not your brain. So in that case, you need to track something that tracks circadian rhythm in the brain and something that tracks circadian rhythm in the body. 语法解析

07:20

So, so far, although many hormones, metabolites, et cetera, have a circadian pattern, many of them are also altered or affected by other factors. Simple example, cortisol peaks in the morning, goes down throughout the day, reaches its lowest level in the evening. But at the same time, if you are stressed or if you're crossing the road and if a truck is coming towards you, then cortisol levels will spike. Or if you're just stressed from work, that will spike. 语法解析

07:49

So then even tracking cortisol rhythm becomes very difficult because within a day, if there is any other stress that's altering your rhythm, then you may not know whether it's cortisol rhythm or something else. The only thing that seems to be 语法解析

08:07

Very resistant to any perturbation but is very solid is melatonin rhythm. But unfortunately, throughout the day our melatonin is pretty low, almost undetectable level, and only rises around bedtime. So that means one has to take multiple samples throughout the night 语法解析

08:25

to get to know what is your melatonin rhythm. And even the melatonin rhythm will tell you what your brain is feeling or how is the circadian rhythm in the brain. But actually it doesn't say much about the rhythm in our gut, liver, et cetera, because the point is almost every organ in our body has its own circadian clock and they all have to work in sync. So that's a challenge. But at the same time, when you're saying that a lot of us who sleep a little late 语法解析

08:55

or eat a little late, it's not a big deal because, you know, it doesn't kill us. But then we've got to pay a little bit more attention to what symptoms might be happening, occurring that might explain that you may be out of sync. So, for example, for many teenagers and young adults, typically circadian rhythm disruption for women will result in irregular menstrual cycle, missing a period or delaying it. 语法解析

09:23

and irritable bowel syndrome, where they might go to the bathroom too many times. They may have difficulty focusing, concentrating, and getting in sync, like really paying attention to your CKD and then might reverse the symptoms. And then you know that, okay, so that might be causing it. And for many healthy adults, you know, nearly 50% of adults now have pre-diabetes or diabetes. And it's very common and 语法解析

09:52

very controlled experiments have shown that even if you take healthy young adults who are very normal, they have normal glucose level and then reduce their sleep to five hours a night. If they habitually are in bed for seven to eight hours every night, you reduce their sleep to five hours every night. And then within a week or so, they become pre-diabetic. So then the question is, is it 语法解析

10:18

the widespread prevalence of pre-diabetes. Is it partly due to circadian rhythm disruption that many young adults go through? So these are the questions. So if you have some of the symptoms, then maybe the first thing to test is whether your rhythms are out of work, whether you're sleeping, maintaining sleep-wake cycle, sleep activity cycle, 语法解析

10:43

and eating fasting cycle and also having enough exposure to light during daytime, not at night. Yeah, because that last point about fasting, sorry, the number, reducing the quantity of sleep and that increasing pre-diabetic in a study, that talks about the quantity of sleep. That's kind of one of the things that I wanted to talk to you about and differentiating that because we often hear sleep more 语法解析

11:12

in order to improve every aspect of your life. I have this aura ring and I've been starting to measure the quality and the quantity of my sleep 语法解析

11:22

And oftentimes when I sleep really well, I'll have blue or green across all of the charts and measurements, REM sleep, deep sleep, quantity. And then my timing would just have like red, like bright red, because I often go to bed at like 2 a.m. or 3 a.m. sometimes. And I just was so frustrated by that. 语法解析

11:45

And it's really when I started to pay attention to more about this idea of the circadian rhythm. So just going back, like we often hear the idea of sleep more, but is it better or is it as important maybe rather to prioritize timing of when we actually sleep? So the circadian timing, even if the total sleep hours may suffer a little bit. Yeah, so it's a difficult question because for different people, it's different. For example, you may be feeling tired 语法解析

12:16

Maybe you are used to going to bed at two o'clock and waking up at maybe it's a nine or something, whatever it is, and you can sleep very well, but then people who are going to bed at two o'clock and waking up at eight or nine or 10 in a busy, noisy neighborhood with no air conditioning, then of course their sleep quality will become really bad. So that's why… 语法解析

12:45

You know, if you can afford to, if you have a quiet house and you're living alone and no one is disturbing you, there's no dog, cat, small children, et cetera, you don't have to pick up drop kids or pick up somebody in the morning so that going to bed at 2 and waking up at 9 or 10 is okay. But most of us actually do have a day job or people are working 语法解析

13:11

caregiving means except for the young adults, for most other adults starting from the age of 30 and onwards, we are giving care to children or giving care to the elders or we are paying attention or we have a job. So then it becomes difficult to go to bed late and have enough 语法解析

13:30

quantity of sleep and also quality of sleep. So that's why from practical point of view, for most people, it may be better to advance that sleep time a little bit earlier so that they can give themselves enough time so that they are not waking up to like alarm clock and pressing the snooze button five times before dragging themselves out of the bed because 语法解析

13:53

You know, when you're going to sleep, and this data is becoming very clear over the last 10, 15 years, that during sleep, we cleanse our brain. So during daytime, there are a lot of activities in our brain, and there are a lot of, you can say, toxins. I won't say toxin, but it's better to describe it that way. Dirt, toxin, whatever you can say, gunk. 语法解析

14:19

that accumulates and literally during our sleep, when the neurons fire together, and one of our leading experts in sleep, they say neurons that fire together shower together. So that means when they fire together at night, synchronized, that's when they produce this wave to cleanse the brain. So it's almost like the brain is going through a washing and drying cycle in your washer. 语法解析

14:49

And just imagine if you wake up to an alarm clock before the washing and drying cycle is complete, you're essentially waking up and putting on dirty clothes that are half dried for the next day. So that's the way to relate. Like when we don't sleep enough, you feel like that. And then to kind of whitewash that or to suppress that, we… 语法解析

15:19

Start our day with coffee. And then people swear by their coffee because when they say that that day cannot begin without coffee, that's a total sign that they are not getting sufficient sleep that rejuvenates their brain to the extent that they can actually drag themselves and start working or start emailing, doing something without a cup of coffee. Yeah. 语法解析

15:43

Yeah. Yeah. And just to reiterate on that timing aspect. So assuming, let's say I go to bed at 2 a.m. and I have the flexibility to get eight hours of sleep so I can still wake up at 10 a.m. No alarm. Yeah. 语法解析

15:58

Is that technically a worse schedule than someone going to bed at 10 p.m. and getting the same eight hours but waking up at 6 a.m.? So it's the same quality of sleep, same quantity, but just the circadian rhythm of the timing is different. 语法解析

16:17

Yeah, I mean, it's not always the wild time because the thing is, if you can do it every single day, then that's fine. Essentially, you are living in a different time zone, literally. Yeah. So I won't say that this is bad because… 语法解析

16:33

The idea is if you can maintain a dark bedroom and go to sleep, say, from 2 a.m. to 10 a.m., and then you are waking up without an alarm clock and you're feeling perfectly fine and energetic, that's fine. Because our circadian rhythms are actually entrenched by or get in sync with 语法解析

16:56

with our exposure to light during daytime or absence of bright light few hours before going to bed. So light plays a big role. And second thing is eating and fasting. So for example, if you wake up at 10 and wait an hour and your first bite is after 11 a.m. and then your last bite is three to four hours before going to bed. So if you're finishing all your food by 10 or 11 at night, 语法解析

17:25

without too much alcohol, then that still, I would say, is a relatively good, consistent circadian life. Because just imagine, suppose say you are stuck in a space station, what would you do? Will you stick to Houston time or will you stick to… 语法解析

17:44

Whoever is funding your mission. So that's the point. So that's the point. Just imagine you are in the space station and you choose a time. Can you stick to that time and maintain these three rhythms? Your light-dark rhythm, eating-fasting rhythm, and sleep-wake rhythm, sleep-activity rhythm. And if you can maintain in right relation to each other, just like I said, during daytime, after you wake up, 语法解析

18:11

So between 10 and evening, 6 p.m. or 7 p.m., if you can go outdoor and get some daylight for an hour or so, then that will take care of your brain executive function, alertness, reduce depression, et cetera. And then the eating, fasting rhythm, if you can maintain the same consistency, then that's fine. Yeah. Yeah. 语法解析

18:37

You talk about the importance of getting light, especially in the moment that you wake up. And I think Hugh Berman also talks about this a lot. And I think people kind of get it, but they don't really see the impact of how much this kind of regulates the circadian rhythm. Talk to us a little bit about that, like the importance of getting bright light, natural light, and what that's actually about. 语法解析

19:03

doing? How is that actually impacting our bodies? Yes, every day our circadian rhythm. So for example, if I lock you in your apartment without any timing cue and with plenty of food and everything else, you have no timing cue, then what will happen is you'll go to bed and wake up in every roughly 24 hours, 15 minutes or 24 hours, 30 minutes. 语法解析

19:28

So that means our internal clock is not necessarily exactly 24 hours. And the reason is from sunrise to sunrise outside the equator is never exactly 24 hours because of the tilt of the planet and then the elliptical route it takes, it's slightly different. So that means every day we are resetting our clock slightly. And that resetting cue comes from bright light, mostly our brain clock and trends by bright light. 语法解析

19:59

So then the idea is when you should get this light or is it advisable to get in the morning versus daytime or evening? And, you know, what happens is our human circadian clock is a little bit or any circadian clock is a bit interesting because during daytime it actually expects light. So light doesn't do anything in changing the clock in the middle of the day. 语法解析

20:25

But in the very beginning of the day, like early in the morning or late in the evening, even around sunset and starting from sunset, say, till you go to bed, light has a huge effect on resetting or resynchronizing our clock. So in that way, one would argue that it's better to get up and get some light because that light syncs your brain clock with the day-night cycle. 语法解析

20:53

Another reason is, you know, if you're traveling and if you want to get over jet lag much quickly, then it's always better to get up and go outdoor, go for a walk or a mild run early in the morning because you get sunlight and also you are artificially cranking up your cortisol level because your cortisol levels should peak around the time you wake up. By running outdoor and having some light, you kind of reset clock and 语法解析

21:23

both your cortisol rhythm potentially and then your circadian rhythm. And then the same thing might be true that in the early evening, like around sunset time, around that time, if you're outdoor and if you get some light, that also helps resetting. 语法解析

21:40

That doesn't mean that you should not go outdoor during daytime because light has multiple functions. One function is resetting the clock, but the other function that relates to most of us on an everyday basis is it improves or uplifts our mood. And a lot of us with stress and other things going in our life, as I said, most of us are caregivers. We spend more time worrying about other people's 语法解析

22:06

or other things than ourselves. So there are a lot of reasons why many of us, almost 80% of us in our lifetime will go through at least one episode of clinically defined depression or anxiety. And there are a lot of us who simply feel low or disinterested in what they do and going outdoor 语法解析

22:29

being under daylight actually is the best antidepressant that everybody has access to. It's plentiful and free. You just have to step outside. So I would say that, yes, if you can, then it's better to go outdoor in the morning after you wake up. You feel fresh. You feel like, yes, it's a new day and you can reset your brain clock. But at the same time, at any time of the day, if you can be outdoor, you don't have to be sitting under the 语法解析

22:59

Bright, full sunlight, but even under a tree, canopy, or next to a large window on the veranda, anywhere, if you can spend an hour, then that's also a good antidepressant. 语法解析

23:14

Gotcha. So it's not necessarily you're saying about the sunlight exposure, meaning if you're living in rainy London, or I'm actually from Vancouver, where it's cloudy and raining a lot, you can just be in a window looking outside, even though it's a cloudy day, just as long as you're getting exposed to daylight, you're still able to reset that circadian rhythm. 语法解析

23:37

Yeah, so when I said window, the problem is as you move away from the window, the daylight falls exponentially, very precipitously falls. So you have to be essentially within a meter from the window, large window. But you're right, even in Vancouver or London in a cloudy day, in a rainy day, you still get 4,000 to 5,000 lux of light. 语法解析

24:05

And 1,000 lux of light for a couple of hours or one hour is considered enough. And when you are getting 4,000 to 5,000 lux of light in a cloudy day, that's plenty of light. Yeah, noted. If you had five to 10 minutes to sit down with a group of late shift workers that, you know, my mom used to work 语法解析

24:31

pretty late hours where she would work from 7 p.m. to 7 a.m. I've got a lot of friends that are working in an emergency room as doctors, and they often have to sleep by the time get home, which is going to be 10, 11 a.m., and they wake up at nighttime. So they're not able to actually get that natural light. And I'm sure you get this question a lot, but if you had this time to educate folks in terms of what are the actionable things they can actually do 语法解析

24:59

that will help reset their circadian rhythm if they're working late night hours. What would you advise? Yeah, so the night shift worker, shift worker are truly, I mean, they took the name away, but I would say the guardians of the galaxy. Because the modern society cannot survive without shift worker. Just imagine from the time you wake up till 语法解析

25:24

time you go to bed, you must have received the service of at least a dozen shift workers every single day. And without them, life will be impossible. So thank you to your mom that she actually saved quite a few lives. And so coming to shift worker, really the most difficult shift worker is the night shift worker. 语法解析

25:47

in a place like Vancouver where the daylight can be very short in wintertime, so there is very little chance to get daylight. And I've talked to many shift workers and one shift worker in particular who was a San Diego cop here, police officer for 25, 30 years. 语法解析

26:10

was always fit, very trim and fit, very uplifting mood. And I asked him, what is your secret? He said, he didn't even know what I work on. He said, you know, 语法解析

26:25

I have the magic trick. Every day, whatever time I come back from work, I make sure that I wake up at least an hour before sunset. I just want to go and get some sunlight before it's out because that's like my secret juice of energy. And sunlight is literally the energy that keeps me going. And it was kind of gratifying to hear that. But, you know, the lucky thing is, 语法解析

26:52

He lives in San Diego, so he can actually get some light even in wintertime. So then for challenging places like northern extreme latitude, the question becomes, how do you get access to light? Because, you know, in winter, by the time you come home, as you said, eight or nine, and then you go to sleep, and by the time you wake up, it's in the evening, again, dark. So this is where… 语法解析

27:20

Having exposure to daylight or daylight mimicking light, bright light is a substitution. And in many Nordic countries, people actually go and get light therapy. That's 5,000 to 10,000 lux of bright light. And nowadays, there are many companies that are coming up with wearable where there is a tiny LED that you can wear on top of your glasses that gives you this blue light because out of the daylight light, 语法解析

27:47

the blue light is the most effective in reducing depression, increasing alertness and resetting our circadian clock. But at the same time, you know, you have to expose to blue light at this specific time. And nowadays there are a lot of ways you can get this light exposure. But the biggest challenge for people out there who are in technology field, my experience, 语法解析

28:15

to you is can you come up with a daylight mimicking light bulb that is under $10? Because right now, most of the light bulbs that we use, mostly they use three LEDs. They don't really mimic daylight because daylight mimicking LEDs cost now more than a thousand bucks from many suppliers. And that innovation will change the life of many, many people. 语法解析

28:46

Are there any cheap alternatives you recommend? Products, brands that are fairly affordable, people can buy? Yeah, so there are some blue light emitting LEDs that you can wear on top of your glasses, which are less than 250 bucks. And 语法解析

29:04

You are not actually looking at super bright light because sometimes that glare can trigger a headache in some people. So these ones, there are quite a few vendors now, and you can look up and find some of those. And even the U.S. military is using some of those for redeploying the troops to reduce jet lag and also increase alertness and alertness. 语法解析

29:30

improve cognition because sometimes the soldiers are actually stuck indoor in a bunker away from daylight for obvious reason. So there are quite a few studies that have shown efficacy of these wearable and sometimes you also see NFL or NBA players wearing them and 语法解析

29:51

trying to reset to the new time zone. So I usually don't talk on behalf of any manufacturers because the first thing is I have not tested that product. So unless I test it, I can't vouch for them. So that's why. Yeah, no, makes sense. If someone isn't able to get that sufficient amount of daylight during their day, 语法解析

30:15

What about the idea of supplementing with extra vitamin D? Because obviously you get vitamin D with sunlight. And I'm just wondering how much efficacy just supplementing with 语法解析

30:27

let's say 10,000 IU vitamin D when you're not getting enough sunlight exposure can have an impact. Because I've heard the same can be done with jet lag in terms of mitigating jet lag when you take a lot of vitamin D. Obviously, we'd love to kind of get your thoughts on that. Yeah, I haven't seen any research that it does anything to reduce. 语法解析

30:53

Because the pathway that research our circadian clock has absolutely nothing, zippo, to do with vitamin D. Vitamin D is synthesized in your skin in response to light, sunlight, and light acts exclusively through only 5,000 neurons in each human retina. And they have absolutely nothing to do with vitamin D. Vitamin D does not play a role in light entrainment of the clock. It does not play a role in light effect on mood. 语法解析

31:21

Or depression. Interesting. Okay. So it's not a substitution by any means? Absolutely not. Got it. Got it. In terms of compensating for lost or poor sleep, if someone has a decent sleep schedule, but one day they're up at 2 a.m. and they're just not able to get enough sleep, are there any tips you would have on compensating 语法解析

31:50

Trying to help reset the circadian rhythm or any activities that they can do that allows them to compensate for lost or poor sleep. Well, the thing is you are synonymizing sleep with circadian rhythm, which is actually wrong because having lost sleep, you can just catch up. You can do catch up sleep. There is nothing wrong in that. 语法解析

32:13

And sleep is only one part of circadian rhythm. And just losing one night of sleep or a few nights of… Like, for example, if you're lying in the bed, you cannot sleep in a dark room. That's not going to change your circadian rhythm. You just feel crappy the next day because you did not sleep. It's almost similar to not eating for… 语法解析

32:36

few hours or gorging too much, it's not going to change your circadian rhythm or it's not going to change your mitochondria or anything in a big way. It just, it's a discomfort. So 语法解析

32:49

What you're saying is if somebody cannot sleep, well, yes, catch-up sleep is much better. And then in the day, if you can, and get a little bit more daylight because now there is enough study showing that daylight exposure actually improves your nighttime melatonin levels. 语法解析

33:08

rise and nighttime melatonin rise correlates pretty well with ability to fall asleep and maintain sleep. So this is one. And then some people find exercising not too close to your bedtime, but maybe late afternoon exercise. And if you can combine it with outdoor lighting, when it's lighted outside, then that also helps people to fall asleep. I mean, yeah. 语法解析

33:36

There's a huge list of 100, 200 things that people can do to improve their sleep. And it has to be kind of personally tailored because some people find taking a shower in the evening helps them. Some people find maintaining a complete dark room, white room helps them. Whereas other people find they want a little bit of light and background music to fall asleep. So one has to really personally experiment with 语法解析

34:02

with the sleep toolbox to find which tools actually help them. Yeah, yeah. The quality of sleep is definitely personalized because I have people that need a bathtub with soap bubbles and classical music with a nice book in order to fall asleep. And that's kind of their daily schedule. Hopefully they're not falling asleep in the bathtub. Hopefully not. No, no, exactly, right? Okay, that's important to note. What are… 语法解析

34:32

What are some of the worst common habits that you found that people in the modern generation are doing that's harming the quality of their sleep? Yeah, I mean, I would say circadian rhythm because, you know, for sleep, you'll find plenty of people out there talking about sleep, staying awake. The biggest thing is 语法解析

34:59

There was a time few many almost more than a decade ago when Netflix CEO declared what is his biggest competitor he said sleep is my biggest competitor so that means all the digital companies they want to take away your sleep your human wakeful you can you can be sold something only when you are awake so all marketers out there want you to stay awake so that 语法解析

35:27

You can see the advertisement. You can see the entertainment. You can pay for it. So that's disrupting everybody's rhythm. And it's the whole marketing arm versus you. And you have to decide how much entertainment and advertisement you want to consume. So that's… 语法解析

35:52

That's the biggest challenge for young adults and a lot of people. Are you referring to like using technology at night, staying up, watching YouTube, getting blue light at night? Is that one of the worst offenders of common sleep? I mean, that's something that one has to personally have some control over. And then other thing is the work pressure because a lot of people, you know, we… 语法解析

36:20

Many of us are not working in nine to five jobs. Work is almost 24/7 now. And you've got to figure out how to balance that life 语法解析

36:32

And when you don't sleep and when you have random bedtime, then you also tend to eat at random time. And eating at random times seems to have way much more worse effect on your body than even many other things that we take for granted or that we think that we can control. So that's why… 语法解析

36:54

Many years ago, we started this concept of time-restricted eating that started from my lab. The first studies were done in my lab on animals, and then we transferred them to and we tested them in humans. And this concept has become now popular as intermittent fasting, but the scientific term is time-restricted eating. And what we find is even… 语法解析

37:14

Shift workers who do 24-hour shift work, they can adopt 8 to 10 hours of eating window and then fast for the rest of the time and they can still maintain their mental performance and physical performance perfectly fine. And they also find it that they fall asleep much better and they can maintain that sleep much longer. 语法解析

37:37

And that was surprising because we always thought about sleep as a product of our stress, light exposure, et cetera. But then eating time to have such a huge impact on sleep, that was kind of unexpected. And not only that, eating within that eight to 10 hours has multiple health benefits from sleep. 语法解析

38:02

the risk for diabetes or reversing in some cases pre-diabetes to even now there are clinical trials or human studies being done to test the effect of time-restricted eating on cancer, prevention, cancer prognosis or treatment and then survival, survivorship of cancer, dementia, Parkinson's disease and obviously pro-obesity, diabetes, cardiovascular disease. So, 语法解析

38:30

When we are thinking about health, it's very hard to find a completely healthy 40-year-old these days because most of us, if you typically find a 40, 45-year-old, then they either have prediabetes, high blood pressure, high cholesterol, or any other condition or depression, anxiety. They're going through a lot of different issues. 语法解析

38:58

So if circadian optimization can benefit multiple conditions, then this becomes a new bedrock for healthy living. And the ideas are very simple. It does not need extensive testing, biomarker tracking, or even buying special food, buying special mattresses, or buying special anything. And the idea is very simple to maintain a healthy 语法解析

39:29

10 hours or so consistent eating window and then 14 hours or so consistent fasting. Of course, once in a while you can eat outside that window, but not regularly. And then trying to be in bed for eight hours. Means when you try to be in bed for eight hours, hopefully you'll get six to seven hours of sleep. And that should be enough for many people. And these simple things can transform health because it can change 语法解析

39:59

Actually, it can improve physical health, mental health, and also in some cases, recovery from injury. So there's nothing out there that can actually address multiple health conditions, improve performance, even among athletes. They can improve their performance and recover much better sooner from injuries by paying attention to circadian rhythms. 语法解析

40:25

Yeah, that study you did with mice was very fascinating where you gave them the same amount of calories but just within a different window and they turned out to be slimmer, healthier compared to the other, I guess, test class. And just to bring it back around improving the quality of sleep and giving yourself enough time, what is it about eating late that is triggering us to have poor quality of sleep? 语法解析

40:57

Well, when we eat for our digestions and absorption of nutrient, a lot of blood circulation goes to the core and there is something called post-prandial thermogenesis. So that means our body actually produces some heat for this digestion absorption process. And it takes at least four to five hours for the food to be digested in the stomach, the second phase of digestion, and then it goes to intestine for further digestion. 语法解析

41:27

So that means when we eat very close to bedtime, body temperature is high post-prandially, and that prevents us from falling asleep because for falling asleep, we need a cooler body. Then the second thing is when we eat close to bedtime, that also overlaps with our melatonin rise because our melatonin begins to rise for an average person two to three hours before we go to bed. 语法解析

41:54

And melatonin, just like it makes our brain to sleep, it also makes our pancreas to sleep. So that means a pancreas doesn't release enough insulin in response to the carbohydrate that we eat in our meal. So as a result, our postprandial glucose can rise a little bit higher, and then in long term, it can lead to 语法解析

42:17

increased risk for pre-diabetes and diabetes and also increased weight gain. And those who are trying to lose weight, again, studies have shown that people who eat earlier than later, they have much better chance in losing weight and maintaining that weight loss. Got it. 语法解析

42:38

You mentioned melatonin. And one of the things that I've done sometimes, especially when I travel, is to supplement with melatonin. I've heard doing it regularly can have some negative effects. Curious to get your thoughts on using supplementation for people that are trying to improve their quality of sleep of melatonin specifically. And if you do, what the dosage amount is. 语法解析

43:07

Yeah, so I don't work on melatonin and it's also very person specific because there are some people who are very sensitive to melatonin. One milligram is enough for them to fall asleep. And for some, they need 15 milligram to get into the bed. So it's really difficult to say. And then another thing is consistent use and tracking of what are the adverse events you have heard because… 语法解析

43:38

I don't know much about is there any adverse event. What I know is if you have too much melatonin in your system in the morning, then it can also affect your postprandial glucose because melatonin, whether you are supplementing or whether your body produces, 语法解析

43:57

If it is in your system, then it can prevent the glucose-induced insulin release. And some people who are taking very high dose of melatonin, it's likely, although it's not again tested, that very few cases there are testing done. Some studies have shown that even people who are taking five milligram of melatonin at night, they still have more than highest amount of their natural body fat. 语法解析

44:24

nightly melatonin level in the morning and even till noon they can have substantially high level of melatonin and whether that melatonin is impairing their glucose response and whether in the long run they will develop or the risk for diabetes goes up, those things have not been tested because you know these are some of the risks. Those are relatively low priority for funding agencies because they want to solve 语法解析

44:52

more serious health issues. So unfortunately, these kinds of studies have not been rigorously done. 语法解析

44:59

Yeah, those are some of the stuff that I've heard as well. The other one that I've heard, which I don't think has actually been tested, is the potential for the baseline need of your body of needing dopamine to increase if you're constantly fueling yourself with melatonin supplements. And as an alternative, if you're doing it on a regular basis, that tryptophan, which is a precursor to melatonin, might be a safer alternative. Yeah. 语法解析

45:25

assuming you're having it with healthy carbs, because you need to pair those two in order for it to cross across your blood-brain barrier. But I mean, if you haven't done studies on that, we don't obviously have to recommend that for people. Yeah. No, I don't think there is enough, any rigorous study on that tryptophan and other supplement. Yeah. Makes sense. So shifting to fasting and time-restricted eating, 语法解析

45:54

Obviously, this is something that you've kind of pioneered with intermittent fasting, which is great that there's becoming more of a trend now for a lot of people. One of the things that I've struggled with when doing IF is understanding what is the right amount of time? When's the meal where I should be consuming most of my meals? I think 语法解析

46:16

From a societal perspective, we've always shifted to dinner becoming the largest meals. And just based on restaurants and how meal plans and menus are formed, it's just that dinner we've always assumed to be the largest meal. Is that if you're looking at the circadian rhythm and the quality of sleep based on your research, should our last meal of the day be our largest or should it be lunch or breakfast? If we're just looking at it from first principles. Yeah. 语法解析

46:45

It's hard to say because, you know, even within our body, although our glucose response is much better in the first half of the day, we are programmed to feel more hungry towards the end of the day. It doesn't mean that late at night, just end of the day. But we have kind of taken it to extreme because, you know, if you are, 语法解析

47:08

If you're eating until 9 or 10 and then going to bed at 11, then that's kind of a little extreme. But if you can finish your meals at 6 or 7 p.m. and you have three to four hours before your bedtime, that means you are going to bed between 10 and 11, then that should still be okay. 语法解析

47:30

But again, what happens is late night dinner doesn't come only with dinner and men course. It also comes with dessert and alcohol and few other things. So the question is, well, indirectly, if you're eating late, if your eating window is such that you are having business dinner and last meals with friends and family, 语法解析

47:54

then your risk for consuming that extra alcohol and desserts, sweets, et cetera, which are not necessarily part of how the nutrition actually goes up. So in that way, you may not be reaping the best benefit of timeless duty. Yeah, that makes sense. I don't know how much your work focuses on prolonged fasting beyond fasting 语法解析

48:21

you know, the daily time-restricted fasting for that 8 to 10 or 12-hour window. But if someone is doing a three-day prolonged fast or five days or 10 days for the ambitious, how does that affect their circadian rhythm? And are there steps that we need to take after an experience like that to try and reset it? 语法解析

48:45

Yeah, I don't work on prolonged fasting for obvious reasons because whatever I do, I want to make it translatable to wider range of people. So for example, I would say anyone from 10-year-old to 100-year-old can eat everything within 12 hours, but not everybody can do prolonged fasting over multiple days. What we have seen is at least in mice, because we can sample more regularly in mice, 语法解析

49:17

Fasting over 24 hours actually dampens our circadian, mouse circadian rhythm. Dampens means there are not too many genes going up or down. They're just kind of in a maintenance mode. They're going very slow and low. And at the same time, I must remind that master circadian clock, there are certain part of the brain that play an oversized role 语法解析

49:45

role in our circadian rhythm and those rhythms continue irrespective of whether we fast or you eat. So those rhythms continue and those rhythms essentially keep us on track. And then when we break our fast, typically depending on whether you're breaking in the morning or afternoon, there will be a different response. 语法解析

50:10

but we don't know how that response actually affects the circadian rhythm in next day, at least in mouse model. But what we know is during this fasting, at least people tell, we haven't seen and we haven't tested this in mice. People tell that they have terrible sleep on the day one fast because they're feeling hungry. Some of them might be having a headache. 语法解析

50:39

So obviously their sleep quality deteriorates on day one, and then day two and day three, they tend to adapt. But there's very little information on how they break their fast and how it affects their circadian rhythm versus sleep. Yeah. 语法解析

50:58

Yeah, yeah. And it's probably a fraction of the audience that would probably need advice around that. One of the things I've still struggled with, actually, and this is all related to circadian rhythm and also sleep, is needing to wake up to pee at night. And I think probably at this rate, I still get up one to two times a day. And I think a lot of people do as well. 语法解析

51:22

Talk to us about the circadian rhythm of our kidneys and what is the time window that we should be drinking our liquids. I know you've done some research around sipping as well after a certain point. Talk to us a little bit about that, about how I can prevent being at night so I can improve my quality of sleep. 语法解析

51:45

Yeah, you're too young to… My kidneys are fine, I think, but yeah. No, I guess what you mentioned, because you are going to bed at two o'clock in the morning, and I don't know what time is your last meal. And it's possible that your kidney is on its own cycle. So most of us, most regular people who are going to bed, say at 10 or 11, not young adults, but middle-aged people, they 语法解析

52:15

typically wake up around in the morning and then they go to pee. So maybe you're, since you're going to bed at two and waking up at 10, I would suspect that around seven or 8 a.m. you're waking up to go to the bathroom because your kidney may be in its own rhythm. And this is a, this is, again, you can say that this is a total sign that your body rhythm, your brain rhythm is slightly out of sync with your kidney rhythm. 语法解析

52:43

And, you know, it's really hard to figure out how you can manage that. For example, if you're drinking a lot of water just two to three hours within two hours before going to bed, then that will definitely trigger you to go to pee. And this is kind of a tricky challenge because you're the first one who actually drinks. 语法解析

53:09

young person who has come up with this issue. Usually older people ask me because of obviously other problems they have. Um, but this is again, uh, 语法解析

53:23

If you don't drink enough water, then your mouth becomes dry and you wake up to drink little, sip little water. And you can sip little water and then go back to sleep if your mouth is dry. I don't see any difficulty in that. I'm sorry I kind of hand-waved this one because it's really hard to 语法解析

53:42

I'd test this. Yeah. I mean, you talked about sipping after a certain hour based on my own kidney circadian rhythm. So for people that also have that issue, I guess after a certain point, maybe 7:00 PM or 8:00 PM, they could focus on sipping and explain why sipping particularly is going to be helpful 语法解析

54:07

for your diminishing potential peeing? How does that work with the kidney? Is it just less activating? Yeah, actually, kidney has a lot of other issues than just water intake. It's also detoxifying, maintaining blood pressure, 语法解析

54:27

and a lot of other stuff. And I think the sipping comment I might have put in Andy's podcast because we're talking about how to not to wake up too many times at night. We haven't done too much work on drinking in big bowlers versus sipping a little bit of water because as you can imagine, these experiments are very difficult to do in humans. 语法解析

54:55

And in mice, it's very hard to water deprive them for many hours and then because the metabolism rate is very different. But the bottom line, I think, was try to be rehydrated, not sufficiently hydrated throughout the day. And then if you have this issue of going too many times to the bathroom, then 语法解析

55:17

maybe sipping a little bit of water three to four hours before your bedtime will help you reduce that chance. But I guess in your case, what I suspect is your kidney rhythms are very strong and your brain rhythms are strong, but they're not in sync. So that's why kidney is waking up to do its job and your brain wants to sleep. 语法解析

55:40

So this is a good example of they are going out of sync. Yeah, no, I agree. I agree. I get the sense the whole pattern here is that everything works better during the day. Yeah. Everything regulates better and you should try to front load as much as you can during the day and then try to wind down everything from food, sleep, food, water, exercise. 语法解析

56:04

And exercise was interesting because you talked about why exercising early in the morning, like the first thing, isn't actually better than earlier in the afternoon or in the evening. Why is that the case? Well, there are many studies that are done showing that exercise late in the afternoon are beneficial for many reasons. And it started with… So it started, I think… 语法解析

56:32

There are some observations in the 80s showing that NFL players, when they fly across the U.S. and play Monday night football, then the West Coast team that flies to the East Coast and plays Monday night football, then they're actually in late afternoon time based on their jet lag, whereas the local team is a little bit late in the night. And the odd of beating the 语法解析

57:01

East Coast team on their home turf was slightly higher. And that led to this. So those who are into sports betting, they can use this information for sports betting. But since then, the focus then went, why? And then people realized that late in the afternoon, a body temperature is pretty good. So it is high, not like early in the morning when it's a little bit cooler. 语法解析

57:29

So when your core body temperature is high, your blood circulation is high, your blood pressure is a little bit higher, and your muscle flexibility is higher, so you don't need too much warm-up. And in that way, your athletic performance becomes much better. At the same time, your brain is not slippier, so it's more active. It had enough food throughout the day, so the motor coordination is much better. Your risk for falling or injury is reduced. 语法解析

57:58

And then in the late afternoon, what happens is since our pancreas slows down, then muscle can drive insulin, sorry, muscle can drive glucose uptake independent of insulin. So in that way, having activity late in the afternoon, early evening actually helps to reduce blood glucose much better than the same exercise early in the morning. And those studies 语法解析

58:27

were done a few years ago and now there are some repeat studies showing similar trend. And blood pressure also is much better regulated by late afternoon exercise than the same exercise in the morning. Having said that, any exercise is much better than no exercise. So if you are pressed for time, just go and do exercise whenever you can. But if you have the luxury of choosing morning versus evening, then maybe you can try 语法解析

58:57

late afternoon exercise. Yeah, it's interesting. You're the first person that I actually heard say that specifically in terms of 语法解析

59:06

the importance of doing it early in the afternoon, but it makes sense based on the regulation of our glucose levels. So we talked about food, exercise, light, sleep as the major dominoes for regulating our circadian cues that often people overlook. Is there anything underrated that people 语法解析

59:31

Based on your research that people are overlooking, perhaps like temperature of where we live or social interactions that you found in your research that may not be major dominoes, but are still important factors for our overall health. Yeah. 语法解析

59:53

I mean, temperature, we lived for most part of human history, we lived in natural temperature. So that means we experienced a high daytime temperature and low nighttime temperature. But in modern days, we're at constant temperature. And there's not much study on whether temperature cycles are better than no cycling and being in a constant temperature. 语法解析

01:00:20

But at the same time, there's also studies showing that higher temperature disrupts our sleep. And many people can attest to that. It's those who are used to sleeping in air-conditioned rooms in summer days within 20 degrees north or 25 degrees north and south of the equator, then they know that it's really hard to fall asleep during summertime. So temperature does have some effect and 语法解析

01:00:51

Then social interaction also has a strong effect because social interaction can entrain our circadian rhythm to some extent. So that means having regular outing or having regular conversation with family and family time or friends time also helps us to entrain our circadian rhythm or at least release stress and have better sleep. Yeah. 语法解析

01:01:18

So last question for you is from all of the tips and ways of optimizing our health and circadian rhythms that we've talked about, if you were to break down what a ideal, maybe ambitiously perfect circadian day from the moment we wake up to the moment we fall asleep, assuming exercise, assuming that we're eating three meals a day and all that stuff, 语法解析

01:01:45

How would you break that down? At a high level, you don't have to go super specific, but from the moment we wake up to the moment we go to bed, how would you personally do that? Yeah, actually, what you're saying is, you're saying most of us say that the day begins the time we wake up, but actually the day begins when you went to bed last night. So I would say from going to bed last night to going to bed tonight, 语法解析

01:02:15

what you should be doing. Interesting, yeah. Because when you go to bed last night determines how well you will sleep, when you will wake up and how repressed you will feel in the morning. So that's why I said the day begins the night before. So try to go to bed at a consistent time and be in bed for eight hours. So schedule your eight hours in bedtime. And because during sleep, 语法解析

01:02:45

Your brain detoxifies, you restore or store memories, you also store whatever you have learned. And many of your growth hormones and repair process both in the brain and outside the brain in the body happens during our sleep. So that's why setting aside eight hours in bed consistently is extremely important. This is the time when you are sending your car to the garage for repair. 语法解析

01:03:14

every single day. Then after waking up, try to wait for at least an hour or two before your first bite because that's when your cortisol level is pretty high, your melatonin is halfway down. If you're not taking any melatonin supplement, then having this high cortisol and significant amount of melatonin can disrupt 语法解析

01:03:39

glucose regulation so that's why one to two hours waiting after waking up is a good idea and then third after again just like going to bed at a consistent time try to be consistent in your first meal that you eat uh or breaking your fast that breakfast meal breakfast 语法解析

01:03:59

Because just like light resets our brain clock, food resets the body clock every single day. So be consistent with your breakfast time and try to eat all your food and energy-containing beverages within 8, 9, 10, or maximum 12 hours. And because during this feeding cycle, 语法解析

01:04:26

Many research have shown that maintaining a consistent eating window of less than 12 hours and fasting for 12 or more, ideally 14 hours or so for adults, helps us restore our circadian rhythm, improve metabolism, reduce inflammation, and also get better night's sleep. And then the next one is try to go outdoor and to get some daylight. 语法解析

01:04:54

Roughly for an hour and also combine that with activity, some physical activity, ideally late in the afternoon, but any time of the day is good enough. And then the next one is as the evening comes in, you should have your last meal at least two, three hours before your bedtime. 语法解析

01:05:17

So that means for the last two to three hours before bedtime, there should be no food and no bright light. You can dim down your light so that you can build up the melatonin that you deserve for better night's sleep. Gotcha. And then I guess exercise, ideally, if you can, if you have the flexibility to in the middle of the day, in the early afternoons to the evening. Late afternoon, if you have the flexibility, otherwise any time of the day. Great. Yeah, I think you have a… 语法解析

01:05:48

a little chart from day to night on TED. So I'm going to make sure I put that in for people to see. Well, Sachin, thank you so much for sharing all the insightful research and information for people to be able to optimize the circadian rhythm. I want to make sure people check out your book. 语法解析

01:06:07

the circadian code lose weight, supercharge your energy and transform your health from morning to midnight longevity book. We're going to have that linked below. Where else can we direct people to or to learn more about you? We also have an academic app called mycircadianclock.org so people can 语法解析

01:06:28

Learn more on the website. And the app is also free. It's academic, so that means we don't sell anything. We don't give any advertisement or we don't sell people's data to third parties. So we use Entirely to figure out how people of different professions, different age, different location, how they habitually eat and sleep. And after two weeks, we also give them enough guidance to understand 语法解析

01:06:57

get on their personal journey on optimizing their CKD into them. Beautiful. All right. We'll have those linked below. Thank you, Sachin. And thanks for tuning in. Thank you. And have a perfect CKD day. 语法解析

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