In space, women would resist better than men

After the journey into space of people who are not highly trained professionals, a study suggests that women are, in terms of immunity, more resistant than men to weightlessness.

While the departure of the second French woman in space, Sophie Adenot, has just been announced, a study shows that women’s immune systems are more resistant to these trips. Explanations with Géraldine Zamansky, journalist at Health Magazine on France 5.

franceinfo: We owe this discovery to a small team of “space tourists”?

Geraldine Zamansky : Absolutely. In 2021, for the first time, 4 civilians went into space for 3 days thanks to the financing of the flight by a billionaire. And this crew, made up of two men and two women, underwent a very large number of examinations before, during and after their adventure. Blood samples have thus shown a change in immune defenses, even in such a short time. And surprise: the cells responsible for fighting infections were much more disrupted for the two male adventurers. This is explained by Professor Christopher Mason, who has just published in the journal Nature (in English) the results of this research carried out at Weill Cornell Medicine in New York.

Does a stay in space not only damage the bones and muscles of astronauts, but also their immune defenses?

Professor Mason indeed recalls the dangers of space flight for the human body. The best known is weightlessness. It causes bones and muscles to weaken. But the absence of gravity on the outside also transforms our internal balances. Our body contains around 65% water: these fluids will move differently! To help understand the brutality of this change, Christopher Mason uses the image of a waterfall. We often talk to you here about the crucial balance of bacteria present in the intestine, for example, the famous microbiota. There, imagine “cascade” movements that the immune defenses must cope with. There is reason to be disturbed. They can also be affected by toxic radiation from cosmic rays.

Is the body less well protected against infections?

This is one of the effects observed. Certain white blood cells become less capable of detecting a microbe for example. And this damage is more significant and longer in men according to the analyzes of the first 4 “space tourists”. The researchers’ main hypothesis is that women’s immune systems are designed to cope with another incredible “internal” reorganization: pregnancy. Thus, he would have better adaptation skills.