Why does obesity make semen worse?

Nowadays, it is well known that obesity is a factor that causes infertility in both men and women. In men, a decrease in the number and mobility of sperm is observed, as well as an alteration in DNA fragmentation. All of this can make pregnancy difficult, since there will be fewer sperm with the capacity to reach and fertilize the egg. An increase in DNA strand fragmentation can also produce poorer quality embryos that do not reach implantation or even increase the abortion rate.

The deterioration of sperm quantity and mobility occurs mainly as a consequence of alterations in hormonal balance. Obesity, mainly, translates into a greater number of fat cells or adipose tissue in the body; and it can produce hormones (leptin) that alter both normal hormonal secretion at the brain level and sperm production directly in the testicle. In addition, there is a higher temperature at the level of the testicles and a greater production of pro-inflammatory substances (adipokines). Both will contribute to greater oxidative stress in the testicle and this will increase DNA fragmentation.

Given that obesity is a growing problem today, it is expected that the population with infertility problems will also increase in the future.