The genistein in soy might also minimize BPA's influence on baby, study finds
By Madeline Vann, Tuesday, July 31, 2007
TUESDAY, July 31 (HealthDay News) -- Fetal exposure to a chemical in plastics can affect infant health, a new study shows, but folic acid, as well as genistein, an active ingredient in soy, may both help protect babies from those effects.
The Duke University research team demonstrated that exposing baby mice in the womb to bisphenol A (BPA), a chemical used in most plastics, changed the physical appearance of the mice, although not their genes.
The results demonstrate that chemical exposures during pregnancy can affect the way genes are expressed, the researchers say.
The researchers used a strain of agouti mice that are known to be born slender and brown. When mouse mothers received BPA, a significant number of the baby mice were born with a yellow coat. Previous studies have shown that yellow agouti mice are also at risk for diabetes, obesity and cancer.
"The fact that the mice fed BPA had a yellow coat and likely would grow to be obese as adults demonstrates that this single substance had a system-wide effect," senior researcher Dana Dolinoy said in a prepared statement. "A comparison between the large yellow mice and the normal brown mice showed identical genetic makeup, yet strikingly different appearances," the researcher said.
"Just as importantly, when pregnant mothers were given folic acid or genistein, the epigenetic [gene expression-linked] influence of BPA was counteracted," Dolinoy added.
BPA is found in a wide variety of products, including plastic water bottles, food containers and baby bottles. While laboratory studies such as this one have demonstrated an impact on animals, there is no clear answer about the potential impact on human health.
Writing in this week's issue of the Proceedings of the National Academy of Science, the researchers note that the amount of BPA used in this study was five times less than the amount considered harmful in mice, demonstrating that even a minimal amount affects the expression of a mouse's genes.
The Duke team suggest that moms who consume folic acid and genistein during pregnancy might help protect their babies from the possible impact of BPA. Their research does not suggest an appropriate dose for humans. Folic acid is a B vitamin that is already recommended for women during their childbearing years, due to its known ability to protect babies against brain and spinal birth defects. Women should take 400 micrograms of folic acid daily, according to government recommendations.