Washington DC: Turns out, sunscreens can be used as a male contraceptive! A new study has revealed that some of its ingredients may disrupt sperm cell function.
The Danish study found that many ultraviolet (UV)-filtering chemicals commonly used in sunscreens interfere with the function of human sperm cells and some mimic the effect of the female hormone progesterone, a new study finds.
Senior investigator Niels Skakkebaek of the University of Copenhagen said that these results are of concern and might explain in part why unexplained infertility is so prevalent.
Although the purpose of the chemical UV filters is to reduce the amount of the sun's UV rays getting through the skin by absorbing UV, some UV filters are rapidly absorbed through the skin, Skakkebaek said. UV filter chemicals reportedly have been found in human blood samples and in 95 percent of urine samples in the U.S., Denmark and other countries.
Skakkebaek and his colleagues tested 29 of the 31 UV filters allowed in sunscreens in the U.S. or the European Union (EU) on live, healthy human sperm cells, from fresh semen samples obtained from several healthy donors. They found that 13 of the 29 UV filters tested induced calcium ion influxes in the sperm cells, thus interfering with normal sperm cell function.
Furthermore, nine of the 13 UV filters seem to induce this calcium ion influx by directly activating the CatSper channel, thereby mimicking the effect of progesterone. This finding suggests that these UV filters are endocrine disruptors, Skakkebaek said. In addition, several of the UV filters affected important sperm functions normally controlled via CatSper, such as sperm motility.
Skakkebaek called for clinical studies to investigate whether chemical UV filters affect human fertility. He added, Our study suggests that regulatory agencies should have a closer look at the effects of UV filters on fertility before approval.
Eight of the 13 UV filters that disrupted sperm cell function are approved for use in the U.S. They are avobenzone, homosalate, meradimate, octisalate (also known as octyl salicylate), octinoxate (or octyl methoxycinnamate), octocrylene, oxybenzone (also called benzophenone-3 or BP-3) and padimate O. These chemicals are common active ingredients in sunscreens as well as sunscreen-containing personal care products, such as makeup, moisturizers and lip balms.
Results of the study are presented at the Endocrine Society's 98th annual meeting in Boston.