IVF treatment appears to be more successful if women consume soy products to protect them from BPA.
People are exposed to the chemical bisphenol A (BPA) when they consume food or drink from water bottles, cans or plastic containers.
BPA can mimic estrogen, one of the two main female sex hormones.
Figures from the US Centers for Disease Control and Prevention (CDC) indicate that over 96% of Americans have BPA in their bodies.
Studies have cautioned that BPA leads to health problems, and some suggest that it contributes to reproductive disorders. It may also hinder fertility treatment.
Soy beans contain a high concentration of isoflavones, a type of plant-made estrogen known as phytoestrogen.
While some of the benefits of soy have been questioned, mouse studies have indicated that a soy-rich diet can protect against reproductive health problems associated with BPA exposure.
Routine soy consumption tied to better outcomes in IVF
Dr. Jorge E. Chavarro - of Harvard T.H. Chan School of Public Health, Brigham and Women's Hospital, and Harvard Medical School in Boston, MA - and colleagues looked at data linking BPA exposure, diet and in vitro fertilization (IVF) success rates.
Participants were 239 women, aged 18-45 years, who received one or more IVF treatments from 2007-2012 at the Massachusetts General Hospital Fertility Center.
The women were part of the Environment and Reproductive Health (EARTH) Study, an ongoing cohort study that is investigating how environmental factors and nutrition affect fertility.
BPA exposure was measured through urine samples. A lifestyle questionnaire was also completed to assess the frequency with which soy-based foods were consumed. Results showed that 176 women consumed soy products.
Compared with women who had a low BPA in their urine, those with a high level of BPA and who did not eat soy foods had fewer successful embryo implantations and fewer pregnancies that developed to the point where the fetus could be detected by ultrasound. They also had fewer live births. In women who consumed soy as part of their regular diet, BPA concentrations had no impact on IVF outcomes.
Senior author Dr. Russ Hauser says:
"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."
The researchers hope that research will explain how soy's protective action works and to find out how other diet and lifestyle changes might protect against both BPA and other chemicals.
Medical News Today recently reported that soy may help prevent osteoporosis in women.