Study links sunscreen to impaired male fertility

Men’s ability to father children in a timely manner may have been caused by certain sunscreen chemicals, according to a recent National Institutes of Health (NIH) study on male infertility called ‘interesting but very preliminary.”

The NIH and the New York state Department of Health’s Wadsworth Center has agreed and noted that the results are initial findings only and that additional studies are needed to confirm the findings.

Sunscreens and other personal care products that protect skin and hair from sun damage have chemicals such as Benzophenone (BP) – type ultraviolet (UV) filters, comprises a class of about 29 other chemicals in the product. Upon absorption by the skin, some of these chemicals can interfere with the body’s hormones and endocrine system processes. Men with high exposure to UV filters of BP-2 or 4OH-BP had a 30% reduction in fecundity – the biological ability to reproduce, researchers found.

“In our study, male fecundity seems to be more susceptible to these chemicals than female fecundity. The women participants actually had greater exposure to the UV filters overall, but their exposure wasn’t associated with any significant pregnancy delays,” said Germaine Louis, PhD, of the NIH’s Eunice Kennedy Shriver National Institute of Child Health and Human Development in Bethesda, MD in a news release. “Our next step is to figure out how these particular chemicals may be affecting couple fecundity or time to pregnancy—whether it’s by diminishing sperm quality or inhibiting reproduction some other way.”

Study findings were published online in the American Journal of Epidemiology (Nov. 13, 2014).

The study was conducted on 501 couples who were trying to conceive, who were recruited from 16 countries in Michigan and Texas in 2005 through 2009. These couples were part of the Longitudinal Investigation of Fertility and the Environment (LIFE) study. This study was established to examine relationships among fertility, lifestyle factors, and exposure to environmental chemicals. The female participants ranged from 18 to 44 years old and the men were over 18; none of them had a medical diagnosis of infertility.

The couples were observed until pregnancy or up to one year of trying to conceive and the researchers recorded the time it took for the women to become pregnant. The researchers tested the participants’ urine samples and measured concentrations of five selected UV filters

associated with endocrine-disrupting activity. The researchers controlled for age, body mass index, and smoking, among other factors.

Their findings suggest that some, but not all, UV filters may be associated with diminished fertility in men, independent of their partners’ exposure. About 75th percent and above among the men were observed with the highest exposure to UV filters BP-2 or 2OH- BP.