Higher levels of sex hormones in older men linked to younger biological age

NEW ORLEANS — Older men who have higher levels of sex hormones may have a lower biological age — that is they may feel physically and mentally younger than they actually are — a new study finds.

Researchers at the University of Western Australia’s medical school say that estradiol, a form of estrogen,  especially seems to influence biological age for men. Estradiol in men is linked to libido, erectile function, and sperm production, but now may have even more greater importance considering these results. People with slower biological aging generally have greater health and longevity as they age.

“As populations grow older and sicker, identifying pathways to healthier aging is important,” said the study’s lead investigator, Bu Yeap, a professor at the university’s medical school, in a news release by the Endocrine Society. “Sex hormones such as testosterone and its active metabolite, estradiol, may reflect or possibly determine biological youth.”

For their research, the authors studied 2,913 older men between 70 and 89, measuring the length of their telomeres, the tips at the end of DNA strands that protect chromosomes, which can determine one’s biological age, found in white blood cells. Telomeres tend to grow shorter as one grows older, and poor health choices (smoking, minimal exercise, unhealthy diet, stress) can increase the process. The effect of sex hormones on telomeres, however, was not established.

The authors then measured levels of sex hormones in the participants from blood samples and found that higher levels of estradiol were linked to longer telomeres. But Yeap notes the findings are based on association, not a cause-and-effect certainty.

“Our finding will facilitate future studies aimed at preserving health in the growing demographic of aging men,” says Yeap. “If future research finds that sex hormone exposure modulates biological aging in men, we would need to test the effect on biological age of giving men testosterone, which is then converted to estradiol. The optimal blood level of estradiol in older men also would need to be determined.”

The study’s results are published in the journal Clinical Endocrinology.