A new male fertility study might change the way consumers look at sunscreens. Some of the UV filters used may be disrupting the normal functions of sperm cells.
Skin cancer affects 8,500 Americans every day with some of them diagnosed with deadly melanoma. To prevent the occurrence, the American Academy of Dermatology recommends slathering sunscreens before sunlight exposure.
However, a Danish study to be presented in Endocrine Society conference expresses that these products may not be entirely beneficial for men since some of the UV-filtering ingredients may be absorbed quickly and alter the way sperm cells function and thus affect male fertility.
The research led by Prof. Niels Skakkebaek of the University of Copenhagen in Denmark extracted sperm cells from fresh samples of semen of healthy males, exposed them to 29 out of the 31 UV-filtering chemicals that have been approved for use in the European Union and the United States, and then tested them on a buffer solution that simulated the conditions of the fallopian tubes of women where fertilization occurs.
The team then focused their attention on CatSper (Cation Channels of Sperm), a type of calcium ion channel that binds to progesterone produced by females and stimulates the production of proteins that can contribute to the sperm's motility or the ability of the sperm to move properly inside the female reproductive organ so it can fertilize an egg.
When CatSper and progesterone bind, they can boost temporarily the amount of calcium ions present in the sperm cells, which can then control how these cells move.
The study suggests that 45 percent of the tested UV chemicals can disrupt the normal function of sperm cells through "induced calcium ion influxes." Further, of the 13 UV filters tested, nine of them could activate CatSper directly that the sperm tend to mimic progesterone effects.
"These results are of concern," said Skakkebaek, especially since the effects can begin even at low doses.
Since these chemicals might contribute to unexplained male infertility, he hopes that "regulatory agencies should have a closer look at the effects of UV filters on fertility before approval," he added. The Food and Drug Administration (FDA) has already issued a comprehensive regulations and guidelines on sunscreens.
