A soy-rich diet may protect women undergoing infertility treatments from the harmful effects of a chemical widely used in food containers, a new study suggests.
Bisphenol A (BPA) — which is found in such items as polycarbonate plastic water bottles and can linings — can mimic estrogen, one of the two main sex hormones found in women, and the chemical has been linked to reproductive disorders.
More than 96 percent of Americans have BPA in their bodies, according to the U.S. Centers for Disease Control and Prevention.
This study included 239 women, aged 18 to 45, who underwent at least one in-vitro fertilization (IVF) cycle between 2007 and 2012. They completed questionnaires about their eating habits (176 consumed soy foods) and their urine was analyzed to measure BPA levels.
Among women who did not eat soy foods, those with higher BPA levels had lower rates of embryo implantation, fewer pregnancies that advanced to the point where the fetus could be seen on an ultrasound, and fewer live births than those with a soy-rich diet, the researchers found.
Among women who regularly consumed soy, BPA levels had no impact on IVF outcomes, according to the study, published Jan. 27 in the Journal of Clinical Endocrinology & Metabolism.
“Our study is the first to show a possible interaction between soy and BPA in humans,” first author Dr. Jorge Chavarro, from Harvard School of Public Health and Brigham and Women’s Hospital and Harvard Medical School, all in Boston, said in a journal news release.
“This is consistent with research in mice that found a soy-rich diet could protect against reproductive health problems associated with BPA exposure. More research is needed to determine why soy has this effect in humans,” Chavarro added.
“Although it is recommended that women trying to get pregnant reduce their exposure to BPA, our findings suggest that diet may modify some of the risks of exposure to BPA, a chemical that is nearly impossible to completely avoid due to its widespread use,” study senior author Dr. Russ Hauser, from Harvard School of Public Health, Massachusetts General Hospital and Harvard Medical School, said in the news release.
“Additional research could help identify other diet and lifestyle changes that may modify the effects of not only BPA exposure, but also exposure to other chemicals,” Chavarro said.
The U.S. National Institute of Environmental Health Sciences has more about BPA.