为了你的肝脏，假期里也别太放纵
编辑:给力英语新闻 更新:2018年1月1日 作者:纽约时报(By STEPH YIN)
脂肪肝病例中，脂肪在肝脏组织内堆积。睡眠或饮食即便只出现短期变化，就像在假期里常常发生的一样，肝脏促进脂肪消化的能力也会受到影响。
假期里，我们中的很多人都会饮酒、熬夜、吃下额外的那块馅饼、睡懒觉。这些行为尽管很有趣，但却会导致我们的生物钟，也就是让身体功能与外部环境相协调的反馈环出现变化。
肝脏是帮助调节身体新陈代谢的器官，不健康的睡眠模式、饮食方面的变化或者饮酒，都会扰乱它的节奏。如果你正在经历消化不良，或者在参加多个假日派对之后变得无精打采，那你的肝脏可能失调了。近年来，生物钟学领域的研究日益表明，为自有其生物钟的肝脏着想，保持规律的作息习惯非常重要。生物钟学是关于生理节奏的科学。
瑞士洛桑联邦理工大学(Swiss Federal Institute of Technology in Lausanne)定量生物学教授费利克斯·内夫(Felix Naef)说，在帮助肝脏全天候调节身体需求方面——例如在饭后储存能量，在睡觉时释放能量——生物钟发挥着重要的作用。
最近的一些研究探究了酒精是如何影响生物钟的。研究人员于今年报告称：夜班工人连续一周每天喝两到四杯红酒后，生物钟出现了变化，肠道内壁比白班工人“更容易破损”，这可能会让他们面临罹患酒精性肝疾病的风险。
该论文作者之一、芝加哥拉什大学医学中心(Rush University Medical Center)的胃肠病医生加思·R·斯旺森(Garth R. Swanson)博士说，他认为任何一个经常让生物钟出现两小时以上变动的饮酒者都面临着这种风险。
“人们不必上几个月或几年的夜班，”他说。“你只要在相对较短的时间里有一系列糟糕的行为，就有可能将自己置于风险之中。”
其他一些以小鼠为对象的研究影响了人们对肝脏循环的理解。
内夫博士和一组研究人员于上月报告称，发现小鼠的肝细胞中有超过500种蛋白质会在一天当中出现丰富的变化。这些蛋白质最终会帮助肝脏过滤血液、处理脂肪和糖。当它们紧凑的节奏被扰乱时，肝脏或许会在解毒、消化等重要过程中跟不上趟儿。
人们每天的肝脏循环是由睡眠、食物和酒精之间的相互作用塑造的。睡眠会影响我们大脑中的主生物钟。像人体的其他器官一样，肝脏在某种程度上被这个主生物钟主宰着。
但肝脏也有自己的内部生物钟，后者会受到食物和酒精的影响。
东北俄亥俄医科大学( Northeast Ohio MedicalUniversity)生物化学教授约翰·Y·L·蒋(John Y. L. Chiang)在以小鼠为对象的研究中发现，睡眠和饮食的短期变化都会影响到肝脏促进脂肪消化的能力。他说，一些长期干扰可能导致脂肪在肝脏中堆积，进而引发“许多不同的问题：脂肪肝、糖尿病、肥胖、心脏病乃至癌症。”
阿拉巴马大学伯明翰分校( University of Alabama at Birmingham)环境卫生科学教授香农·M·贝利(Shannon M. Bailey)称，酒精还能让小鼠肝脏的运行节奏失常。她的团队最近发现，小鼠被喂食适量酒精满一个月后，其肝脏生物钟会被严重扰乱。
密歇根大学(University of Michigan)生理学副教授雷音（Lei Yin，音)说，要让肝脏的生物钟在这个假期里如常运转，你就得避免极端行为。
这意味着要保持规律的作息时间，从而让主生物钟维持常态。你可以稍微晚睡一会儿，但尽量别比正常就寝时间晚两小时以上。一个管用的小贴士是早上出门散步。“沐浴在阳光里是对我们的内部生物钟进行重置的最有效方式，”雷音博士说。
这还意味着始终清醒地认识到食物和酒精会如何影响你肝脏的生物钟。少喝一点酒没什么问题，但要避免酗酒，其定义是在两个小时内饮酒四或五杯以上。
从短期来看，遵守这些准则或许可以让你在假期结束后较为容易地回归现实。从长期看，规律作息、少饮酒可以保护新陈代谢、预防疾病。
谁有新年计划了吗？
翻译：李琼
Your Liver Doesn’t Know It’s the Holidays
Over the holidays, many of us will drink, stay up past bedtime, eat an extra slice of pie and sleep in. Fun as they are, these activities can tamper with our circadian rhythms, the feedback loops that sync our body’s functions to our external environment.
The liver, which helps regulate your body’s metabolism, gets thrown off by unhealthy patterns of sleep or by changes in diet or alcohol consumption. If you’re experiencing indigestion or your energy levels are low after too many holiday parties, your liver could be out of sync. In recent years, more and more research in the field of chronobiology, the science of biological rhythms, suggests the importance of maintaining a consistent schedule for the sake of your liver, which has a clock of its own.
Circadian rhythms are important for helping the liver anticipate the body’s demands throughout the day, like stockpiling energy after meals and releasing it when we sleep, said Felix Naef, a professor of quantitative biology at the Swiss Federal Institute of Technology in Lausanne.
Recent studies have examined how alcohol affects circadian rhythms. This year, researchers reported that night shift workers given two to four glasses of wine each day for a week had altered circadian rhythms and “leakier” intestinal linings than day workers, which could put them at risk of alcoholic liver disease.
Dr. Garth R. Swanson, a gastroenterologist at Rush University Medical Center in Chicago and an author of the study, says he believes this risk applies to any drinkers who frequently shift their circadian rhythms by more than two hours.
“People don’t have to be working night shifts for months or years,” he said. “You could potentially put yourself at risk just by doing a series of bad behaviors for a relatively short amount of time.”
Other studies in mice have implications for understanding the liver’s cycles.
Last month, Dr. Naef and a team of researchers reported finding more than 500 proteins in mice liver cells that shift in abundance over the course of the day. These proteins ultimately help the liver filter blood and process fats and sugars. When they are thrown off their tight schedules, the liver might lag in important processes like detoxification and digestion.
Our daily liver cycles are molded by an interplay between sleep, food and alcohol. Sleep affects the master clock in our brain. Like most other bodily organs, the liver is partly governed by this central rhythm.
But the liver also has its own internal clock, which can be affected by food and alcohol.
In studies with mice, John Y. L. Chiang, a professor of biochemistry at Northeast Ohio Medical University, has found that even short-term changes in either sleep or diet can affect the liver’s ability to contribute to fat digestion. Chronic disturbances, he said, may lead to fat accumulation in the liver, which can cause “many different problems: fatty liver disease, diabetes, obesity, heart disease and even cancer.”
Alcohol can also knock a mouse’s liver rhythms out of whack, said Shannon M. Bailey, a professor of environmental health sciences at the University of Alabama at Birmingham. Her team recently found that feeding mice moderate levels of alcohol for a month significantly disrupted the functioning of their liver clocks.
To keep your liver’s clock consistent this holiday season, avoid extreme behaviors, said Lei Yin, an assistant professor of physiology at the University of Michigan.
That means maintaining your central circadian rhythm with a regular sleep schedule. You can stay up a little later, but try to avoid doing so more than two hours past your normal bedtime. A helpful tip is to go on a walk in the mornings. “Light is the most powerful way to reset our internal clock,” Dr. Yin said.
It also means staying cognizant of how food and alcohol affect your liver’s timers. Try to stick to normal mealtimes. And it’s fine to drink a little, but avoid binge drinking, which is defined as more than four or five drinks in two hours.
In the short term, sticking to these guidelines might ease your transition back to reality, once the holidays are over. In the long term, maintaining a regular schedule and drinking less can safeguard your metabolism and prevent disease.
New Year’s resolutions, anyone?