Global Study Finds 54% Drop in Male Testosterone Over Five Decades

A meta‑analysis presented at the European Society of Human Reproduction and Embryology (ESHRE) annual meeting in London reported a 54% decline in total testosterone levels in men between 1972 and 2019, equivalent to more than 1% per year. The analysis, led by epidemiologist Hagai Levine of the Hebrew University of Jerusalem, pooled data from 118,593 men in Israel, the United States, Brazil, Finland and Denmark and identified a sharp acceleration of the decline after 2000. Researchers linked the trend to rising obesity, diabetes, metabolic syndrome and exposure to endocrine‑disrupting chemicals, and warned that indiscriminate testosterone supplementation could further harm male fertility.

In response, fertility specialists at Portugal’s Ferticentro, including embryologists Mariana Belchior and Bruno Barauna, recommended lifestyle measures to improve sperm quality: quitting smoking, maintaining a healthy weight, following a Mediterranean diet, exercising regularly (but not excessively), limiting alcohol, avoiding prolonged testicular heat and managing stress and mental health. These changes are said to produce measurable improvements in semen parameters within three to six months.