Common Compounds in Soaps, Toothpastes Could up the Risk of Male Infertility; Study Finds

Common, "non-toxic" chemicals used in everyday products such as soaps and toothpastes could up the risk of male infertility, new study suggests.

The study, conducted by a German - Danish team of researchers, found that common chemicals in cosmetics interfere with sperm function. According to the authors, these chemicals belong to a class of compounds called endocrine disruptors and might be the reason behind the rise in number of male infertility cases in the western world.

These compounds target the body's endocrine system or the hormone systems and lead to problems associated with development and reproduction. Hormones play a crucial role in regulating biological functions from conception through adulthood and even in old age. Some common examples of endocrine disruptors include DDT and bisphenol A (BPA).

Previous research, conducted on rhesus monkeys, has shown that BPA can lead to birth defect and can shorten reproductive lifespan.

Researchers at the Center of Advanced European Studies and Research in Bonn, Germany, and the University Department of Growth and Reproduction, Rigshospitalet, Copenhagen, Denmark have developed a method that can be used to screen these chemicals.

In the present study, researchers tested 100 chemicals. They found that a third of these, including 4-methylbenzylidene camphor (4-MBC), which is used in sunscreens and triclosan, used in toothpastes, led to loss of sperm function.

  "For the first time, we have shown a direct link between exposure to endocrine disrupting chemicals from industrial products and adverse effects on human sperm function,'' said Niels E. Skakkebaek, professor and leader of the Danish team, according to a news release.

Researchers focused on the impact of these chemicals on the CatSper ion channel. The channel controls sperm's swimming abilities. The team found that the presence of the chemicals broke the sequence of the events that lead to the sperm reaching and penetrating the egg. The chemicals changed sperms' swimming abilities; they became less sensitive to progesterone and prostaglandins, which are two important female sex hormones that guide the sperms toward the egg.

The study is published in the journal EMBO reports.