A Hearty Breakfast Could Reduce Jet Lag in Older Adults, Study Finds

The Washington Post

15:44 JST, September 9, 2023

Many people, especially older adults, suffer from jet lag, the grueling fatigue and brain fog that accompanies long-distance travel. Breakfast may offer a simple and effective solution.

Eating a hearty breakfast in the time zone of the final destination may help older adults recover more quickly from jet lag, researchers from Northwestern University and Santa Fe Institute wrote in a study published Tuesday. Avoiding a meal late in the night before, if possible, may also help.

“Having a fixed meal schedule or having a heavier breakfast can be beneficial to reset your clock,” said Yitong “Pepper” Huang, a postdoctoral fellow at Northwestern University and the lead author of the study, which published in Chaos: An Interdisciplinary Journal of Nonlinear Science.

Jet lag can be worse for older adults

Our brain’s 24-hour circadian clock and the network of peripheral clocks in nearly every tissue and organ drive our body’s functions. They respond to a number of cues, including light exposure, food and physical activity.

As we age, our network of circadian clocks is more prone to misalignment, but it’s not yet clear why this happens, researchers say. It could be, in part, because the lens of our eyes turn yellow over time, affecting how we perceive light and changes in brightness.

Jet lag is one symptom of misalignment, which occurs when the internal circadian rhythm doesn’t match the day-and-night schedule outside.

Huang and her co-authors developed a mathematical model to simulate the potential effects of aging on the circadian rhythm during long-distance travel, changing variables of the model to reduce the body’s sensitivity to light or to weaken the ability of the circadian clocks to communicate. Researchers create mathematical models to simulate our body’s processes to better understand how we may react to certain changes in our environment.

Using the model, they found that it may take five days for a person’s circadian clock to acclimate to a six-hour time difference on a trip flying west and six days for a trip east. For older adults, the model predicted it may take seven and nine days respectively.

The model’s predictions echo findings in similar studies on mice, the researchers say. They cautioned, however, that the results depicting a decline in the circadian clock’s ability to acclimate to the new environment as humans age needs to be borne out in clinical trials.

The research in this study was partially funded through grants from the National Institutes of Health, the National Science Foundation and the Simons Foundation.

How to counteract jet lag

The model in the new study simulated four 24-hour meal schedules:

Four equally spaced meals throughout the day and night.

Three meals when hungry.

Three equally spaced meals during the daytime.

Three days of eating a large breakfast and skipping a nighttime meal.

The researchers found that “getting out into the sunshine, getting light and eating a good breakfast” appear to have the biggest impact on adjusting the circadian rhythm, said Rosemary Braun, a co-author of the study and an associate professor of molecular biosciences, applied mathematics and physics at Northwestern University.

“All things being equal, you might feel that you recover from the jet lag faster if you really focus on eating breakfast at a fixed time every day,” she said.

The model didn’t consider the number of calories in a meal or the type of food, but researchers found that a larger meal earlier in the day appears to be better for regulating the circadian system than eating equal-sized meals throughout the day or eating a late-night meal, Braun said. A heavy breakfast and no late-night meal could shave off two days of recovery time from jet lag, the model showed.

A person taking an evening flight from New York to Paris, for instance, could eat an early dinner before they arrive at the airport and skip the in-flight meal – avoiding a “late-night” meal on Paris time. Eating late at night can confuse our circadian clocks; our brains may think it’s time for bed as our liver responds to the food we ate.

Once they’ve landed, they could have a substantial breakfast.

The model was based on a six-hour time difference, but the study findings could also be reasonably applied to a shorter time difference – for instance, the three-hour time difference between New York and Los Angeles – the researchers said.

The model in the study makes certain assumptions such as that light and food are the only cues that affect our internal clocks. Other factors such as exercise or taking supplements of melatonin, a hormone that is produced by the pineal gland in response to darkness or dim light to help us sleep, were not considered.

A ‘novel’ study of two clocks

Meal times can be a “very powerful resynchronization” of the body’s circadian rhythm, said Ilia Karatsoreos, a professor in the department of psychological and brain sciences at the University of Massachusetts Amherst who studies the impact of circadian rhythm disruption on health.

“We kind of already knew all these things,” said Karatsoreos, who was not involved in the study. “But, I think, the way that they’ve put their tool together, it could help us ask some questions or generate some hypotheses.”

If the study’s findings bear out in clinical trials, the recommendation to eat a big breakfast could be a “godsend” for frequent travelers, said Samer Hattar, the chief and senior investigator for the section on light and circadian rhythms at the National Institute of Mental Health, who was not involved in the study. Based on the modeling, though, “it looks as if it works pretty well.”

The mathematical model is interesting because it considers two different clocks that respond to light and food, said Satchin Panda, a professor at the Salk Institute for Biological Sciences and the author of “The Circadian Code,” a book on the importance of maintaining your circadian rhythm.

“In that way, all of this is very novel,” said Panda, who was not involved in the study. “Most of the models in circadian rhythm take into account how light affects the clock. But, there are very few that take into account how food affects the clock.”

When he and others who study circadian rhythm travel internationally, they “typically avoid food in flight,” Panda said, and try to immediately switch to the food schedule of the new time zone.

The good news is that the breakfast options in Europe are typically much better than in the United States, he said.