Everyday chemicals damage male sperm

Chemicals in toothpaste, sunscreen and plastic damage the sperm

05/12/2014

Hormonal effective everyday chemicals, such as those found in foods, plastic bottles, textiles, household products, cosmetics and toys, can cause lasting damage to male fertility. This is the conclusion of a study by a German-Danish research group of the Center for Advanced European Studies and Research (Forschungszentrum caesar) in Bonn and the Rigshospitalet in Copenhagen. The study was published in the journal „EMBO reports“.

For a long time there is a suspicion that so-called „endocrine disrupting chemicals“ (translated: „Endocrine disrupting chemicals“) can have a negative effect on fertility. But proof of this thesis has been difficult. The researchers have therefore developed a procedure that allows the effects of chemicals „on human sperm can be reliably and quickly examined.“Around 100 hormonally active substances have been tested by the method and found drastic impairments of the sperm. The chemicals found in many everyday items could „co-responsible for fertility disorders that occur more frequently in the Western world“, according to the Communication from the Center for Advanced European Studies and Research.

Calcium concentration in the sperm is disturbed
More than 30 of the tested chemicals lead the results of the research team around Dr. Ing. According to Timo Strünker from the caesar research center and Professor Niels E. Skakkebaek from the Copenhagen University Hospital „Disorders of the calcium household of sperm.“ Among the products in which the chemicals are used were, for example, sunscreen milk (ingredient: 4-methylbenzylidene camphor, 4-MBC), toothpaste and cosmetics (ingredient: antibacterial triclosan). Also, the plasticizer Di-n-butyl phthalate (DnBP) had significant impairment of the sperm result. Was examined the „Interaction between the substances and a cation channel of sperm (CatSper), which controls the calcium concentration in sperm“, the researchers report. The chemicals tested would have opened the so-called CatSper channel at concentrations as they occur in the human body, so that the calcium could flow into the cell. If the calcium concentration changes, so does the sperm swimming behavior. In addition, the calcium concentration has a significant importance in penetrating the egg shell.

Swimming behavior and penetration into the oocytes impaired
The swimming behavior and the enzyme release, which helps to penetrate the egg shell, are controlled by the female hormones progesterone and prostaglandins in the fallopian tubes. However, their effect is mimicked by the everyday chemicals, which leads to it, „that sperm are less sensitive to these hormones“, report Timo Strünker and colleagues. The endocrine disrupting chemicals confused the fertilization process, disturbed the navigation of the sperm towards the oocyte and the penetration of the sperm into the egg cell difficult, so the researchers. In addition, there is an interaction between the various chemicals, and that the substances unfavorably complement each other in their effect. So have a „endocrine disruptor cocktail“ from different substances, „despite the sparingly effective concentrations of each component - large calcium responses in spermatozoa“ triggered. Similar cocktails could also be detected in human blood, the researchers write.

EU Directive is intended to regulate the use of chemicals
Overall, the scientists rate the results of their study as extremely alarming. The EU Commission must also take this into account in the current review of the guidelines on limit values ​​for endocrine disrupting chemicals. Last year was „The question of whether to further restrict the use of these substances has been controversially discussed between endocrinologists and toxicologists“ Service. Well could „we demonstrate for the first time that a variety of widely used substances have a direct effect on human sperm“, stressed Professor Niels E. Skakkebaek. The actual „Work provides scientific evidence that helps to develop new guidelines”, Timo Strünker continues. Restrictions in the use of hormonally active substances seem urgently needed given the clear results of the German-Danish research team. (Fp)