The organ clock: why your liver works harder at night than you do

Ever heard of the organ clock? No? You're definitely not alone. The so-called organ clock comes from Traditional Chinese Medicine (TCM): each of the twelve organs is assigned two hours in which particularly much energy, the Qi, flows through it. Twelve hours later, it rests. Quite fairly organised, really.

It gets especially interesting at night. Between 9 and 11 pm the “triple burner” takes command, less an organ, more a system connecting all energy circuits. Translated: the body winds down, pulse and blood pressure sink. Time to relax.

From 11 pm to 1 am the gallbladder is active, processing rich food and detoxifying. Which is exactly why heavy late-night meals are about as helpful as an espresso before bed. Between 1 and 3 am the liver runs at full speed, and yes: alcohol gives it plenty of extra work. According to TCM, people with liver trouble often wake precisely in this window.

From 3 to 5 am the lungs take centre stage, maybe grandma wasn't entirely wrong about sleeping with the window open. Between 5 and 7 am the large intestine reports for duty (a glass of warm water in the morning helps), and from 7 to 9 am the stomach would, according to TCM, much prefer a warm breakfast to hastily gulped coffee to go.

What does this mean for sleep? Evening relaxation, light meals and less alcohol support the body's night shift. Alcohol between 11 pm and 3 am is considered an absolute sleep killer, gallbladder and liver get involuntary overtime.

And yes: the organ clock is no exact timetable; every body works differently. But the idea that our body works diligently at night while we sleep is somehow reassuring. Or at least while we try to sleep.