Your liver doesn't know it's the holidays

Freshly poured glasses of draught Grolsch beer.
Freshly poured glasses of draught Grolsch beer. PHOTO: BLOOMBERG

Poor sleep patterns and changes in diet or alcohol consumption can put it out of sync

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 are 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.

RESETTING THE CLOCK

Light is the most powerful way to reset our internal clock.

ASSISTANT PROFESSOR OF PHYSIOLOGY LEI YIN of the University of Michigan.

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 professor of quantitative biology Felix Naef 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 Centre in Chicago and an author of the study, said he believes this risk applies to any drinker who frequently shifts his circadian rhythms by more than two hours.

Other studies in mice have implications for understanding the liver's cycles.

Last month, Professor 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 moulded by an interplay between sleep, food and alcohol.

Sleep affects the master clock in our brain. Like most other 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.

To keep your liver's clock consistent this holiday season, avoid extreme behaviours, said assistant professor of physiology Lei Yin of 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," Prof Yin said.

It also means staying cognisant 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?

NYTIMES

A version of this article appeared in the print edition of The Straits Times on December 30, 2016, with the headline 'Your liver doesn't know it's the holidays'. Print Edition | Subscribe