Human genes and immune systems change with the seasons

The seasons of the year seem to have a profound effect on how human genes and immune systems work. And this may explain why some diseases get worse in the winter and we seem to be healthier in the summer, according to a new study.

Detection of genes and human immune system changes seasonally

An international team of researchers analyzed blood and tissue samples from more than 16,000 people worldwide. Of the 22,000 genes (almost all of the genes that humans possess) are considered, 1/4 shows clear signs of seasonal variation.

People are usually healthier in the summer because the genes involved in our immunity change with the seasons.(Photo: Corbis)

Genetic changes that attracted the attention of the research team are the most important of these are genetic changes related to immunity and especially inflammation . During the cold winter months - from December to February for those who live in the northern hemisphere and from June to August for people in the southern hemisphere - these genes are more active.

When studying people living near the equator , where heat is relatively high throughout the year, experts recognize a different pattern. Immunity and inflammation in these cases are related to the rainy season , when diseases, such as malaria, are more raging.

In Iceland, where the weather is almost cold all year round, the team notes fewer genetic changes and more seasonal immunity.

Dr. John Todd, a member of the research team from Cambridge University, said, the findings could explain why people are susceptible to certain diseases at specific times of the year. . For example, although the genes involved in immunity (the body's defense against infection) are more active in cold months, it helps us fight off viruses like influenza, but they can do it. onset or exacerbation of diseases such as type 1 diabetes, heart disease or rheumatoid arthritis - a disease when the body attacks itself.

According to Professor Todd, it is difficult to separate exactly what is happening, because many factors affect the risk of each individual's disease. Similarly, diseases and other factors, such as diet and stress, can affect the functional activity of genes.

Mr. Todd emphasized that new research results could help us adjust the cure or even plan for future pathological studies.