A team of researchers from the University of Jyväskylä, in Finland, think they have discovered why the life expectancy of women is longer than that of men (in France, it is 85.4 years for women and 79. 3 years for men). After studying and comparing the chronological age and the biological age (that is, the age of the cells) of more than 2240 people born in the same year, including pairs of twins of different sexes, they found that compared to women, men were biologically older and that this biological aging starts from the age of 21 to gradually accelerate.
At 50, men are “older” by 4 years
For this study, the researchers divided the volunteers into two age groups: 21-42 years and 50-76 years. And also composed a group of younger twins, from 21 to 30 years old. The study of their DNA has made it possible to calculate the acceleration of epigenetic age as a measure of biological aging. For the age group of 21 to 42 years, the biological age of men was 1.2 years higher than that of women. But this difference increases as men and women age and for the age group 50 to 76, the biological age of men was 4.3 years higher.
For the Finnish researchers, the fact that men age faster than women is partly due to body mass index (men tend to be more overweight than women) and smoking (to date, it there are more smokers among men than among women, although the gap is clearly narrowing). But this difference can also be explained “by sex differences in genetic factors and the beneficial effects of estrogen, a female sex hormone, on health” explains Dr. Anna Kankaanpää, lead author of the study.
Source : Do Epigenetic Clocks Provide Explanations for Sex Differences in Life Span? A Cross-Sectional Twin Studythe Journals of gerontology, October 2022
