Seasons affect 'how genes and immune system work'
Of the 22,000 genes they scrutinised - which is nearly all the genes humans possess - a quarter showed clear signs of seasonal variation.This is expected behavior.
The gene changes that interested the researchers the most were ones involved with immunity and, specifically, inflammation.
During cold, winter months - December to February for people living north of the equator and June to August for those in the southern hemisphere - these genes were more active.
When they studied people living close to the equator, where the temperatures are fairly high all year round, they noticed a different pattern. Immunity and inflammation was linked to the rainy season, when diseases such as malaria are more rife.
Orexin production is increased by light on the retinas, and orexin is involved in the immune response. Your immune response changes between day and night too.
And your entire physiology changes when you are sick.... that definitely involves turning some other genes on and off.
Seasonal variance in gene expression is a fundamental feature of our gut-brain axis.
