An ingredient in sunscreen and other personal care products may increase the risk of developing endometriosis, an incurable, painful condition in which uterine tissue grows outside the uterus.
According to a report published in the American Chemical Society's journal Environmental Science & Technology, a type of benzophenone (BP) used in some sunscreens and personal care products may be the culprit. BP, which is also a component of products such as shampoos, makeup, and skin care items, is very effective in blocking ultraviolet rays from the sun. However, small amounts can be absorbed through the skin and enter the blood where it mimics the effects of the female hormone estrogen. Endometriosis, which affects 1 in 10 women of reproductive age, needs estrogen to develop.
To investigate whether or not BP might raise the risk of developing endometriosis, scientists analyzed BP levels in the urine of 625 women who underwent surgery for endometriosis. They found that high levels of one BP called 2,4OH-BP were associated with an increased risk being diagnosed with endometriosis. Women tended to have higher levels of BPs during the summer months; levels also tracked higher if they lived in sunny California, further suggesting a link with sunscreens. "Our results invite the speculation that exposure to elevated 2,4OH-BP levels may be associated with endometriosis," say the researchers.
About 30 to 40 percent of women with endometriosis are infertile, making it one of the top three causes of infertility in women.