Endocrine disruptors threaten fertility from birth

By Mélodie CapronnierPublished on ShareSend by e-mail

Cancers, developmental disorders... The dangers of endocrine disruptors on health have been known for many years. A study by Inserm and the University of Lille published on November 18, 2021 in the journal Nature Neuroscience is particularly interested in the effects of bisphenol A on fertility problems. According to them, early exposure to this substance has significant consequences on reproductive functions.

How Bisphenol A Impacts Fertility

Reproductive function in mammals, including humans, is regulated by GnRH neurons. During pregnancy, they first appear in the nose of the fetus before migrating to the hypothalamus, part of the brain, where they come to control these functions: puberty, acquisition of secondary sexual characteristics, or even fertility in adulthood. .

The migration is made thanks to neural cells, the astrocytes. They encounter the GnRH neurons during what is called "mini-puberty", which begins a week after birth. However, the study shows that exposure to bisphenol A from the first days prevents communication between neurons and astrocytes. To find out, the researchers notably injected bisphenol A into rats daily within 10 days of their birth. The female rats then had a delayed puberty and an estrous cycle (equivalent to the menstrual cycle in women) disturbed. “Our results raise the idea that early exposure to food-contact chemicals, such as bisphenol A, may disrupt the onset of puberty and have a lasting impact on reproductive function,” the authors explain. of the study.

The harmful effects of endocrine disruptors from birth

Thanks to the work of researchers, we understand that early exposure to endocrine disruptors has deleterious effects from the first days of life, and this on fertility and hormonal functioning, but not only. "Failure of integration of GnRH neurons during mini-puberty may lead to a predisposition to develop puberty and/or fertility disorders, but also potentially affect brain development and thus lead to disorders of the learning or even metabolic disorders such as overweight", explains one of the authors of the study, Vincent Prévot, research director at Inserm, in a press release.

Bisphenol A, banned but still present

Bisphenol A is used to manufacture plastic. Recognized by France as an endocrine disruptor, it has been banned since 2015 in baby bottles and food containers. Six years later, we might expect to find no more in these products... But this is not the case, indicates Vincent Prévot. "Despite its ban, bisphenol A is still present in our environment due to the slow degradation of plastic waste, but also because it is found in food containers purchased before 2015 and which have been kept. With the recycling of waste, the bisphenol A contained in plastics dating from before 2015 could also be found in new products", warns the researcher. In addition, little is known about the effects of the products used to replace it...