Study: UV filters interfere with sperm function

Researchers report in a new in vitrostudy published in Endocrinology that 13 of the 29 ultraviolet (UV) filters they looked at interfere with sperm function. Many of the UV filters are allowed in U.S. sunscreens.

While the study’s lead author Anders Rehfeld, M.D., Ph.D. student, at the University of Copenhagen in Denmark, tells Dermatology Times, in vivo studies are needed to confirm these results, he says the findings should draw the attention of people who are trying to have children, as well as sunscreen manufacturers.

Dr. Rehfeld’s and colleagues’ investigations on human sperm cells showed that some chemical UV filters mimic effects of progesterone, sending signals that cause fertilization to fail. When released by cumulus cells around eggs, progesterone induces a Ca²⁺ influx into human sperm cells by way of the CatSperCa2+ channel. The researchers thought chemical UV filters might mimic progesterone’s action on CatSper, thereby impacting Ca²⁺ signaling in sperm cells, according to the study.

They found that 13 UV filters induced significant Ca²⁺ signal at 10µ M. Of those, eight are allowed in U.S. sunscreens. They are: Menthyl Anthranilate (meradimate), Ethylhexyl Salicylate (octisalate), Homosalate (HMS), Ethylhexyl dimethyl Paba (OD-PABA), Benzophenone-3 (BP-3), Ethylhexyl Methoxycinnamate (octinoxate), Octocrylene (octocrylene) and Butyl Methoxydibenzoylmethane (avobenzone).

Other studies have measured octinoxate in blood after topical application of sunscreen, and measured the first metabolite of OD-PABA in semen after topical application of sunscreen, according to Dr. Rehfeld.

“Our results call for some concern regarding the widespread use of these chemicals UV filters, but as our experiments have all been carried out in vitro…, it is too early to say if there is an in vivo effect on the fertility changes of couples trying to get pregnant,” Dr. Rehfeld says. “If, however, a couple is concerned about this particular issue, or if they are having trouble achieving fertilization, it might be worth a try to recommend [that they] avoid exposure to the chemical UV filters … by switching to sunscreens with physical UV filters instead….”

Sunscreen manufacturers probably are also concerned about these results, according to the researcher.

“My guess is that they are already planning to phase out some of these chemicals, perhaps even before they are forced to do so through regulation. A similar trend has been seen for other chemicals, when evidence has mounted regarding their possible disruptive effects on human health,” Dr. Rehfeld says.

Disclosure: The study authors report no conflicts of interest, according to the study.