音频长读：科学揭示如何获得最佳夜间睡眠

这一刻，亚历克斯的一英里游泳对他和我们所有人都意义非凡。在EverNorth专业医疗服务机构，我们协助医疗提供者确保患者护理不中断，特别是针对罕见病、慢性病和复杂病症。现在亚历克斯和他的护理团队通过EverNorth专业药房Accredo提供的救命药物和护理管理，控制住了血友病，因此亚历克斯可以成为最后离开泳池的人。EverNorth专业服务——因为每分每秒都至关重要。访问evernorth.com/specialty了解更多。

This moment, Alex's mile swim, it means everything to him and to all of us. At EverNorth Specialty Services, we help providers make sure patient care doesn't get interrupted, especially for rare, chronic, and complex conditions. Now Alex and his care team have his hemophilia under control with life saving medication and care management from EverNorth's specialty pharmacy, Accredo, so Alex can be the last one out of the pool. EverNorth specialty services because every moment counts. Visit evernorth.com/specialty to learn more.

这是来自《自然》杂志的长篇音频解读。本期主题：如何获得最佳夜间睡眠。科学观点，作者Lynn Peoples，朗读者Benjamin Thompson。从抖音上鼓吹口贴胶带和重力毯的视频，到杂志评选助眠枕头排行榜，睡眠建议无处不在。这并不奇怪。

This is an audio long read from Nature. In this episode, how to get the best night's sleep. What the science says, written by Lynn Peoples and read by me, Benjamin Thompson. From TikTok videos touting mouth tape and weighted blankets to magazines ranking insomnia curbing pillows, sleep advice is everywhere. And it's no wonder.

全球各地的人们都在抱怨失眠和睡眠不足，催生了一个年价值超过1000亿美元的助眠产品市场。但俄勒冈健康与科学大学的昼夜节律科学家Andrew McHill警告说，网络偏方和昂贵工具并不总是有效，而失败的改善尝试可能产生负面影响。他表示，这可能让人们放弃寻求帮助，情况会变得更糟。相反，研究人员指出昼夜节律科学的启示——过去五十年揭示了遍布全身的生物钟网络。这套计时机制确保生理系统在正确时间做好正确准备，比如抵御病原体、消化食物和睡眠。

People all over the world complain of insomnia and not getting enough sleep, driving a market for sleep aids worth more than 100,000,000,000 US dollars annually. But scientists warn that online hacks and pricey tools aren't always effective, and failed attempts to remedy the situation could have negative effects, says Andrew McHill, a circadian scientist at Oregon Health and Science University in Portland. It could discourage people from finding help, and things could get worse, he says. Instead, researchers point to the lessons coming from circadian science, which over the past five decades has exposed a network of biological clocks throughout the body. This timekeeping machinery ensures that physiological systems are primed to do the right things at the right times, such as defend against pathogens, digest food, and sleep.

但昼夜节律钟不会自行精确运转。要保持同步和最佳功能，它们需要阳光、日常作息和其他线索的规律校准。现代生活往往与之相悖——人们大部分时间待在室内，深夜进食，

But circadian clocks don't cycle precisely on their own. To stay in sync and function optimally, they need regular calibration from sunlight, daily routines, and other cues. Modern life doesn't often cooperate. People spend much of their time indoors. They eat late into the night.

工作日与周末的睡眠时间不统一，相当于给自己制造时差。代价是高昂的：短期内，昼夜节律紊乱和睡眠不足会降低认知能力、情绪和反应速度；长期则可能增加感染、糖尿病、抑郁症、痴呆症、癌症、心脏病和早逝风险。为改善睡眠和整体健康，MacKill等科学家强调三个要点：明暗对比、固定进餐时间和保持睡眠规律。

They shift sleep schedules between workdays and weekends, effectively jetlagging themselves. The toll is steep. In the short term, circadian disruption and insufficient sleep can reduce cognition, mood, and reaction time. In the long term, they can increase risks of infections, diabetes, depression, dementia, cancer, heart disease, and premature death. For better sleep and overall health, MacKill and other scientists emphasize three basics, contrasting light and dark, consolidating mealtimes, and keeping sleep times consistent.

Mac Hill表示，白天简单外出散步并减少晚间光照就能产生显著效果。光线是昼夜节律系统最强大的信号，其中蓝光波长尤为有效。这并非巧合——人类是在户外天空下进化的，而正午天空富含蓝光。

Simply taking a walk outside during the day and reducing our light exposure in the evening could have great effect, says Mac Hill. Light provides the most powerful signal to the circadian system. Blue wavelengths are especially potent. That is not a coincidence. Humans evolved outdoors under the sky, and the midday sky is rich in blue light.

然而，关于夜间避免蓝光的常见建议只揭示了部分真相。1990年代的一系列发现证明，眼睛中存在不直接参与视觉的光敏细胞，这些细胞通过接收视杆和视锥细胞的强度与波长信息，将数据传递至大脑的生物钟起搏器，从而实现生物钟同步。斯坦福大学睡眠与昼夜节律科学家Jamie Zeitza指出：'昼夜节律系统需要充足光线才能正常运作，但我们很难准确判断自己获得的光照量。'

Still, common advice about avoiding blue light at night captures only part of the story. In the nineteen nineties and February, a string of discoveries proved the existence of light sensitive cells in the eye that are not directly involved in seeing. Rather, these cells synchronize body clocks. They detect both intensity and wavelength with input from rods and cones and relay those data to a circadian pacemaker in the brain. The circadian system requires bright light to operate properly, but we're pretty bad at determining how much light we're getting, says Jamie Zeitza, a sleep and circadian scientist at Stanford University in California.

典型的家庭照明亮度在100到250勒克斯之间，对眼睛来说可能感觉很强，但昼夜节律系统专门识别的富含蓝光的自然光亮度要高得多，即使在阴天也能达到10000勒克斯以上。时间也很重要。白天明亮的蓝光能同步昼夜节律，促进夜间褪黑激素的分泌——这种荷尔蒙信号告诉身体该睡觉了。它还能提高警觉性和认知表现。而夜间来自人造光源和发光屏幕的相同光照会扰乱昼夜节律系统。

Typical home lighting of a 100 to 250 lux might feel like a lot to the eye, but the blue rich daylight that the circadian system primed to detect shines orders of magnitude brighter, upwards of 10,000 lux even on an overcast day. Timing matters too. Bright blue light during the daytime synchronizes circadian rhythms and supports the nightly surge of melatonin, the hormone signal that tells the body it's time to sleep. It can also boost alertness and cognitive performance. The same illumination at night from artificial lights and glowing screens confuses the circadian system.

蓝光是最强的干扰因素，但夜间任何颜色的足够光子都会改变节律、抑制褪黑激素水平并妨碍睡眠。扎伊采尔表示，深夜时段的暴露（如打开厕所灯）破坏性最大。昼夜节律系统在睡眠中点对光线最敏感，此时最不预期有光。研究表明，即使是走廊灯泡这样的微光也会提高夜间心率并损害睡眠。科学家指出，最终最关键的是明暗对比——明亮的白天与黑暗的夜晚。

Blue light is the strongest disruptor, but enough photons of any color at night can shift rhythms, suppress melatonin levels, and hinder sleep. Exposure in the middle of the night, such as with a flip of a toilet light switch, is most disruptive, says Zaitser. The circadian system's sensitivity peaks near the midpoint of sleep when it least expects light. Studies show that even a dim light, such as a hallway bulb, can raise overnight heart rates and impair sleep. Ultimately, scientists say what matters most is contrast, bright days and dark nights.

纽约西奈山伊坎医学院光与健康研究中心主任玛丽安娜·菲格罗表示，事实上白天的光照能缓冲夜间光线潜在的危害。越来越多的研究将白天更多光照与更强的昼夜节律和更高的睡眠质量联系起来。一项针对大学生的研究发现，与黄昏后的光照相比，他们白天的总光照时间更能预测就寝和起床时间。菲格罗说，白天获得的光照越多，晚上睡得越好。白天光照太少而夜间光线太多甚至可能缩短预期寿命。

In fact, light during the day can buffer against the potential harms of light at night, says Mariana Figuero, director of the Light and Health Research Center at the Icahn School of Medicine at Mount Sinai in New York City. Mounting research links greater daytime light exposure with stronger circadian rhythms and higher sleep quality. One study of college students found that their total hours of light exposure during the day better predicted their bedtimes and wake times than did light exposure after dusk. The more light you get during the day, the better you'll sleep at night, says Figuero. Too little daylight and too much night light could even shorten life expectancy.

英国一项针对近9万人的研究发现，即使考虑了收入和身体活动等因素，光照模式最差的20%人群预计比习惯最健康的20%人群早去世约五年。该研究的作者之一、澳大利亚阿德莱德弗林德斯大学的睡眠健康科学家安德鲁·菲利普斯将解释归于昼夜节律：'它们调节着你生理的每个方面'。遗憾的是，在现代社会实现这种昼夜对比很困难。室内照明偏向于对视觉有益但对节律信号无用的绿光波长。

A UK study of nearly 90,000 people found that the twenty percent with the poorest light exposure patterns were predicted to die around five years earlier than were the twenty percent with the healthiest habits, even after accounting for factors such as income and physical activity. Andrew Phillips, a sleep health scientist at Flinders University in Adelaide, Australia and an author of the study, pins the explanation on circadian rhythms. Quote, they regulate every aspect of your physiology, end quote. Unfortunately, achieving this daily contrast is difficult in the modern world. Indoor lighting leans on green wavelengths that serve vision but not circadian signaling.

节能规范限制了灯具的亮度。通过窗户进入的日光被快速稀释，节能玻璃和防蓝光镜片涂层进一步减少了到达眼睛的节律刺激光子数量。老龄化加剧了这个问题——人的晶状体会随时间变黄并过滤更多蓝光。昼夜科学给出的处方是：多花时间在户外、靠近窗户坐、白天使用模拟日光的LED灯。

Energy usage codes limit how bright those fixtures shine. Daylight entering through windows gets quickly diluted, and energy efficient window glass and blue light blocking spectacle lens coatings further reduce how many circadian stimulating photons reach the eyes. Aging compounds the problem. People's lenses become more yellow over time and filter out more blue light. Circadian Science's prescription, spend more time outdoors, sit near windows, and use daylight mimicking light emitting diode lamps during the day.

傍晚时分调低灯光亮度并关闭屏幕，或使用能调暗屏幕或切换至暖色光谱的应用程序，厕所可考虑使用低强度琥珀色夜灯。科学家指出具体方案因人而异——即使是同龄人对相同光线的反应也可能大不相同，可能与性别或眼睛颜色等特征有关。当光线来自屏幕时，内容本身可能和光线同等重要。扎伊采说：'如果你晚上11点还在用iPad，那么光线暴露可能会产生某些影响。'

In the evening, lower the brightness of lamps and power down screens, or use apps that dim or shift screens to a warmer spectrum, and consider a low intensity amber nightlight for the toilet. Scientists note that the precise prescription is personal. Even people of the same age can vary considerably in how they respond to the same light, possibly because of characteristics such as sex or eye color. And when light comes from screens, the content can matter as much as the light itself. If you're on an iPad at eleven at night, then the light exposure might have some effect, says Zaitse.

但如果你在做放松的事情，可能会抵消这种影响。卡路里摄入也与昼夜节律和睡眠密切相关。上午10点的人体肝脏和晚上10点的肝脏是完全不同的器官，身体其他处理食物的部位也是如此。饥饿激素、消化酶和调节葡萄糖的胰岛素也有自己的节律。

But if you're doing something relaxing, that might outweigh the effect. Calorie intake is also intricately linked with circadian rhythms and sleep. The human liver at 10AM and the human liver at 10PM are very different organs. The same can be said for other parts of the body that process food. Hunger hormones, digestive enzymes, and glucose regulating insulin have rhythms too.

圣地亚哥索尔克生物研究所的昼夜节律科学家Emily Manougian指出：人类生理结构本就不适合全天候进食。上午晚些时候到下午早些时候是身体最准备好接收热量的时段。深夜进食会打乱生物钟，导致消化关键步骤无法完成，还会破坏肠道微生物群从而引发失眠。更严重的是，夜宵会使血液涌向消化道并提高核心体温，抵消促进睡眠的夜间自然体温下降。

Humans are simply not equipped to deal with food at all hours, says Emily Manougian, a circadian scientist at the Salk Institute for Biological Studies in San Diego, California. Late morning to early afternoon is when the body is usually most prepped for incoming calories. Eating late in the evening disrupts clocks and leaves key steps of digestion incomplete. It can also disrupt the gut microbiome, which could contribute to insomnia. What's more, late meals send blood to the gut and raise core body temperature, countering the natural nighttime dip that promotes sleep.

这些行为还会升高血糖水平，使肝脏和肾脏的生物钟与大脑主生物钟脱节，增加起夜概率。Manoukian等学者建议复兴古训：早餐吃得像国王，午餐像王子，晚餐像农夫。最后一餐至少应在睡前3小时完成，且之后避免零食或含热量饮品。食物质量同样关键，高糖高饱和脂肪的饮食会降低睡眠质量并导致片段化睡眠。

And they elevate glucose levels and uncouple liver and kidney clocks from the core clock in the brain, raising the chance of midnight toilet trips. Manoukian and others suggest reviving the old adage, eat like a king in the morning, a prince at noon, and a peasant at dinner. That last meal, they say, should fall at least three hours before bedtime, ideally with no subsequent snacks or caloric drinks. Food quality matters too. Diets high in sugar and saturated fat lighten and fragment sleep.

Manougian表示：咖啡因会持续作用数小时，酒精的干扰性则具有欺骗性——你可能入睡但睡眠质量会很差。反之，白天摄入植物性食物可能改善睡眠。研究表明核桃能提升褪黑素水平和睡眠质量。哥伦比亚大学营养与睡眠科学家Marie Pierre Saint Ange参与的研究发现，白天摄入更多果蔬的人夜间睡眠更连贯。

Caffeine lingers for hours, and alcohol is deceptively disruptive. You might fall asleep, but the quality of your sleep will be quite poor, says Manougian. On the flip side, eating some plant based foods during the day could improve sleep. Research shows that walnuts boost melatonin levels and sleep quality. Marie Pierre Saint Ange, a nutrition, sleep, and circadian scientist at Columbia University in New York City, coauthored a study that links greater daytime intakes of fruit and vegetables with less fragmented sleep.

若睡前必须加餐，Sontonge推荐酸奶或格兰诺拉麦片等易消化轻食。另一种选择是夜间采集的牛奶——相比日间采集的含有更多褪黑素和更低压力激素皮质醇。研究证实母乳也存在类似波动，建议新手父母在储奶瓶标注早晚时段，以帮助婴儿和自己获得安稳睡眠。在正确时段睡觉的重要性不亚于睡眠时长，Phillips说这就像花同样的钱获得更大收益。

If a bedtime snack is unavoidable, Sontonge recommends something light and easy to digest, such as yogurt or granola. Another option, if you can find it, cow's milk that has been collected at night contains more melatonin and lower levels of the stress hormone cortisol than does milk collected during the day. Research confirms that similar fluctuations occur in human breast milk, suggesting that new parents might want to label pumped bottles with AM and PM to help their babies and themselves to sleep soundly. Sleeping at the right time can be just as, if not more, important than getting lots of sleep. You're getting more bang for your buck, says Phillips.

昼夜节律系统与睡眠稳态系统协同调节睡眠，后者通过腺苷分子诱发睡意。清醒时腺苷在血液中积累，睡眠时被分解。但仅靠腺苷不足以启动和维持优质睡眠。例如通宵后早晨8点，昼夜节律信号会通过升高体温和警觉性来对抗高腺苷水平。要使稳态系统与昼夜节律同步，就需要根据个人生物钟保持固定作息。

The circadian system regulates sleep in tandem with the sleep homeostat, a separate system that influences drowsiness through a molecule called adenosine. Adenosine builds up in the bloodstream while a person is awake and is broken down during sleep. But it alone isn't enough to initiate and maintain quality sleep. At 8AM after an all nighter, for example, circadian signals would be promoting wakefulness by raising body temperature and alertness, countering high adenosine levels. Aligning the homeostat with circadian signals means going to bed and waking up at consistent times in tune with a person's biology.

这个最佳睡眠窗口对早鸟型和夜猫型人群截然不同。严苛的工作学习安排难免会与某些人的生物钟冲突，最突出的矛盾是青少年生物钟自然后移与学校早课时间的对立。研究显示至少80%上班族和学生依赖闹钟，证明多数人生活与生理节律脱节。长期被闹钟唤醒造成的睡眠剥夺，导致很多人通过休息日补觉来补偿，而夏令时与标准时的切换更造成额外紊乱。

This optimal sleep window will differ for an early bird versus a night owl. So inevitably, strict work and school schedules will conflict with someone's internal clocks. Perhaps the most glaring mismatch is that teenagers' rhythms naturally shift later even as school bells ring earlier. Research estimates that at least 80% of workers and students rely on alarm clocks, evidence that most are living in discord with their biology. Accumulated sleep deprivation over days of waking with an alarm causes many people to compensate by sleeping in on nonworking days, Springing forward to daylight saving time and falling back to standard time adds further whiplash.

节律失调和不规律的影响远超睡眠质量。Phillips团队发现每日睡眠不稳定的死亡率预测效力高于总睡眠时长。其另一项研究显示，心力衰竭患者若睡眠不规律，发生再次住院或死亡等医疗事件的风险是规律睡眠者的两倍。Phillips指出：我们需要重塑对睡眠的认知——这不仅仅是完成每日配额那么简单。

The risks of misalignment and inconsistency go beyond poor rest. Phillips and his colleagues found that an unstable day to day sleep schedule alone predicted mortality better than did total sleep hours. Another study he coauthored showed that people with heart failure who had irregular sleep patterns had twice the risk of another medical event, such as hospitalization or death, compared with regular sleepers. We need to reframe how we think about sleep, says Phillips. It's not just about hitting a daily quota.

菲利普斯表示，专注于任何一个因素都能帮助其他方面步入正轨。规律的饮食时间可以固定睡眠时间，进而更容易获得晨光并避免夜间光照。不过，科学家指出，要获得这些益处并不需要完美遵守规则，人们应在力所能及时进行调整。例如轮班工人虽然面临这三方面的障碍，但适当妥协能让他们更接近目标。

Focusing on any one factor can help the others fall into place, says Phillips. A regular eating schedule can anchor sleep timing, which, in turn can make it easier to get morning light and avoid light at night. Still, adhering perfectly to the rules is not necessary to reap the benefits. People should adjust what they can when they can, scientists say. Shift workers, for example, face barriers to all three, but compromise can get them closer.

即使在夜间工作时坚持白天进餐，也能降低轮班工作带来的诸多风险，如情绪障碍和血糖问题。圣安吉指出，人们还可以利用其他行为线索，比如晨间高强度锻炼能促进夜间睡眠。生活也需要灵活性——马努吉安允许自己偶尔与朋友共进深夜晚餐，而睡眠严重不足的人可以在非工作日补睡一两个小时。

Eating meals during the day even while working nights could lower many of the risks associated with shift work, such as mood disorders and blood sugar problems. And people can use other behavioral clues, such as exercise. A hard morning workout promotes nighttime sleep, says Saint Ange. Life also calls for flexibility. Manougian allows herself the occasional late dinner with friends, and people with a large sleep debt can benefit from an extra hour or two of catch up sleep on nonworking days.

尽管睡眠小工具可能无法治愈失眠，但有些工具能引导更健康的习惯。可穿戴追踪器和光线传感器可提供个性化反馈。谷歌工程师科里·麦克莱恩（麻省剑桥）曾合著过关于大型语言模型用于个人健康的论文，他设想数字设备能给予温和提醒：'如果发现你工作日就寝时间规律但周末波动较大，就会建议将此作为改进方向。'欲阅读更多《自然》的长篇新闻报道，请访问nature.com/news。

Although sleep gadgets might not cure sleeplessness, some tools could guide healthier habits. Wearable trackers and light sensors might prompt users with personalized feedback. Corey McLean, an engineer at Google in Cambridge, Massachusetts and coauthor of a paper on using large language models for personal health, imagines digital devices giving a nudge. Quote, if it sees you tend to go to bed at a reasonable hour on weekdays, but then you're much more variable on weekends, it could suggest that as an area for improvement, end quote. To read more of Nature's long form journalism, head over to nature.com/news.

此刻，亚历克斯正在进行一英里游泳。这对他和我们所有人都意义非凡。在EverNorth专业服务公司，我们帮助医疗服务提供者确保患者护理不被中断，特别是针对罕见病、慢性病和复杂病症。现在亚历克斯和他的护理团队通过EverNorth旗下专业药房Accredo提供的救命药物和护理管理，已控制住血友病情。因此亚历克斯可以成为最后离开泳池的人。

This moment, Alex's mile swim. It means everything to him and to all of us. At EverNorth Specialty Services, we help providers make sure patient care doesn't get interrupted, especially for rare, chronic, and complex conditions. Now Alex and his care team have his hemophilia under control with life saving medication and care management from EverNorth's specialty pharmacy, Accredo. So Alex can be the last one out of the pool.

EverNorth专业服务——因为分秒必争。了解更多请访问evernorth.com/specialty。

EverNorth specialty services because every moment counts. Visit evernorth.com/specialty to learn more.