Jet lag and other circadian disorders are common in the modern world. What if you could treat jet lag with simple changes like altering the times when you eat?
If you have ever flown across time zones or worked a night shift, you know what jet lag feels like. This disorder occurs when your body abruptly changes to a different sleep-wake cycle. There is no real cure for jet lag; for most people, the best approach is simply to wait until our bodies adjust, a process that can take days and sometimes weeks. However, new research indicates that adjusting meal times may help to treat jet lag and get our circadian rhythm back on track.
Mealtime and the Circadian Rhythm
You may be aware of the effect of sunlight on the circadian rhythm, or the 24-hour internal clock most mammals possess. However, there are actually many different clocks in our bodies, each of which responds to different cues. For example, glucose and insulin levels follow the 24-hour day-night cycle. In turn, these have an effect on our overall circadian rhythm and sleep-wake cycles. The circadian rhythm of glucose, also called blood sugar, appears to respond especially quickly to changes in mealtimes and fasting.
How can a change in mealtime affect the circadian rhythm? Researchers examined this by studying a group of healthy young men. These men were fed meals spaced by five hours. Some had their first meal early in the morning while other had it five hours after waking. The circadian rhythm of their blood sugar levels was delayed in people who had late meals. In turn, this appeared to affect the expression of circadian genes in other tissues, such as PER2 in adipose, or fat, cells. Because our bodies systems are all interrelated, the circadian rhythms of different tissues can affect each other and cause a shift that will effectively treat jet lag. Delaying a meal by even a few hours can affect our circadian rhythm.
What Causes Jet Lag?
Jet lag is caused by an abrupt change in your schedule that leaves your circadian rhythm out of sync with the rest of the world. For example, consider flying east by three time zones. You will need to wake three hours early, go to bed three hours earlier and perform all of your daily activities at a new time.
Our bodies release hormones such as melatonin and cortisol at specific times when they help us to wake or sleep. Our digestive tracts also have a distinctive rhythm, releasing different hormones and digestive compounds at the times when we need them to digest and metabolize food properly. A person suffering from jet lag has to eat, sleep and wake at times when their body is not prepared. This can cause fatigue, sleepiness, grogginess, insomnia, loss of appetite and a wide variety of symptoms.
Despite the name, flying over time zones is not the only time when people suffer from jet lag. We also may have symptoms from changing schedules, getting up earlier than normal, and even from daylight savings time. Even eating at different times can lead to circadian dysfunction. This is why scientists generally recommend that we eat at regular times in addition to going to sleep and waking at the same times every day.
New Evidence-Based Ways to Treat Jet Lag
Changing your mealtimes in advance of a trip or other change in schedule may help to prevent or treat jet lag by resetting your internal clocks. There are also other effective ways to reset your internal clocks. Combining fasting with delayed mealtimes has been found to be effective in other studies. Getting plenty of natural light during times when you wish to be awake, as well as avoiding this light when you want to sleep, can help. Melatonin supplements have also been found to help to prime your body for sleep until your brain adjusts to your new schedule.
This study presents a new and natural way to treat jet lag, but also a reminder of how important our circadian rhythm can be. It is important to keep a relatively stable schedule in sleeping, waking and eating so we can live with optimal health and avoid the unwanted symptoms of jet lag.