Can Chocolate for Breakfast Help With Jet Lag? It Works for Rats
Jet-lagged after a long flight? A healthy helping of chocolate for breakfast could help synchronize you to a new time zone, if a recently published study on rats holds true for humans.
Most forms of life on Earth, including humans, operate on a circadian rhythm, a natural, internal process that regulates the sleep-wake cycle. Light, or lack thereof, hugely affects this rhythm. In humans, regular disruption – perhaps in the form of chronic jet-lag or late-night work shifts – can increase the risk of obesity, metabolic diseases, cardiovascular problems, and even cancer.
Buoyed by previous research suggesting that timed food intake can help synchronize biological clocks to different day-night cycles, scientists at the National Autonomous University of Mexico explored whether chocolate could help resolve jet-lag in rats if eaten for "breakfast" at the beginning of their new "day".
Three groups of rats were exposed to a sudden six-hour advance of their light/dark cycle. Rats in one group were given five grams of milk chocolate each day at the beginning of what would be their new "day" (breakfast). Rats in another were given chocolate near the end of their new "day" (equivalent to devouring lots of chocolate before bedtime). Rats in the final, control group weren't given chocolate at all.
It took rats in the control group about a week to return to normal activity, but rats given chocolate for breakfast returned to normal in four days. Rats given chocolate towards the end of their active cycles remained sluggish even longer than controls.
The researchers don't think there's anything inherently special about chocolate's ability to resynchronize circadian rhythms, just that it contains a lot of hyper-palatable fats and sugars, as well as a dose of caffeine, which stimulate the brain and cue wakefulness. Eating other foods with a similar nutrient profile for breakfast could trigger jet-lag-resolving effects as well.
As always with studies like these, it must be noted that rats are not humans, so it's uncertain whether the results will translate to us. Moreover, rats in the study were fed a fair amount of chocolate – roughly equivalent to a 75-kilogram (165lb) human eating three to four Hershey chocolate bars for breakfast. Resolving a case of jet-lag might not be worth that stomachache.
Source: Escobar, C., Espitia-Bautista, E., Guzmán-Ruiz, M.A. et al. Chocolate for breakfast prevents circadian desynchrony in experimental models of jet-lag and shift-work. Sci Rep 10, 6243 (2020). https://doi.org/10.1038/s41598-020-63227-w