How do the seasons affect them?

Season changes do not only play on our morale, they impact other elements of our metabolism such as alcohol tolerance, the waist or even our response to drugs. Here is what researchers from the University of Nagoya (Japan) discovered.

Their results were presented in the journal Nature Communications April 28, 2025.

The activity of several genes varies with seasonal changes

To understand how the organic clock varies depending on the seasons, the Japanese team became interested in Rhesus monkeys, a primate closely related to humans. The researchers analyzed more than 54,000 genes expressed in 80 fabrics. They then identified several “Seasonal variation genes “.

More precisely, they spotted the existence of seasonal fluctuations in the genes responsible for the metabolism of drugs, in particular the CYP2D6 and CYP2C19. They affect a quarter of current treatments. “Several widely used drugs could be affected by these seasonal variations, including cancer treatments, diabetes, hypercholesterolemia, psychiatric disorders, hormonal therapies and immunosuppressants used in organ transplantation”explain the authors in their press release.

Scientists have also noticed differences in the expression of seasonal variation genes according to the sexes. In females, those involved in the metabolism of carbohydrates had a more marked activity in winter and spring in the duodenum (initial segment of the small intestine) compared to the males. “The increase in the metabolism of carbohydrates in the duodenum is essential for the body to extract the maximum energy from rare foods during the winter months, which could explain frequent weight gain during this period. Then, in the spring, with the increased availability of food, the metabolism of carbohydrates is intensifying to extract the energy of a more diverse diet”add the experts.

Alcohol: The effects of the drink are more important in summer

During another test, led to test alcohol tolerance changes depending on the seasons, scientists have raised mice in winter and summer conditions. They found that rodents raised in winter conditions were recovered more quickly from alcoholic poisoning.

“This result suggests that the organism is more likely to get into summer”explains Professor Takashi Yoshimura who led the study. “This is an interesting discovery because it could explain why the number of patients hospitalized for acute alcoholic poisoning is higher in summer in most countries.”

But more importantly, this work suggests that the time of year should be taken into account to improve patient care. The researchers thus argue for the development of chronotherapy, that is to say taking into consideration the circadian pace during patient care.