US Edition
Jet lag can be alleviated by eating a hearty breakfast in the morning of a new timezone, scientists have advised.
Most travellers suffer a sluggish, nauseating feeling when travelling a long way east or west as the body struggles to reorient itself to a new pattern of daylight.
The phenomenon is caused because humans have multiple internal clocks all picking up signals from the environment and switching bodily functions on or off accordingly.
The brain’s clock, for example, depends on daylight, while the organs calibrate themselves by mealtimes, and sleep cycles are influenced by darkness and a drop in temperature - one of the reasons we struggle to sleep in a heatwave but grow drowsy in cold weather.
When the clocks drift out of alignment jet lag takes hold, but a new study has shown that eating at the correct time can help resynchronise the clocks, speeding up the transition to a new timezone.
“Having a larger meal in the early morning of the new timezone can help overcome jet lag,” said author Dr Yitong Huang, a researcher at Northwestern University in Illinois, US.
Misalignment between internal clocks
“Constantly shifting meal schedules or having a meal at night is discouraged as it can lead to misalignment between internal clocks.
“Conflicting signals, such as eating when your brain is about to rest, can confuse internal clocks and cause desynchrony.”
Research has shown that circadian clocks are present in almost every cell and tissue in the body but previous studies have tended to focus on just one time cue - such as sunlight - and single clocks, rather than looking at how they all synchronise together.
For the new study, published in the journal Chaos, the team built a mathematical model which mimicked different clock rhythms in the body and their influence on each other.
They were then able to disrupt the rhythms using signals, such as decreased light, to see how problems with one caused disturbance with other body clocks.
Resetting the mean time clock helped other rhythms recover more quickly after they were disrupted.
The team also found that as humans age internal clocks become less sensitive to light and less able to communicate with each other, meaning that it will take longer to recover from jet lag as people grow older.
Future research on preventing jet lag
The researchers now want to investigate what can be done to prevent jet lag in the first place, and keep internal clocks more synchronised in later life.
Learning how to fight jet lag could also help protect people whose clocks are regularly misaligned because of shift working.
Previous studies have shown that disrupting the body clock has a serious impact on health, raising the risk of heart attacks and strokes by more than 40 per cent.
Around six per cent of the genes of the body are directly linked to our internal clocks or circadian rhythm, and switch on at certain times of the day or night.
Scientists from the Sleep Research Centre at the University of Surrey found that 97 per cent of these “clock” genes move out of sync when sleep patterns deviated from the norm.
They also found that certain genes responsible for releasing “products” which keep the immune system working properly do not switch on in people who sleep during the day.