Washington, Sept 04 : Previous studies have linked exposure of Bisphenol A (BPA), a chemical found in many plastic products, to a staggering number of health problems.

Now, new evidence from mouse studies suggests that pregnant women exposed to BPA could give birth to girls who are at a greater risk of developing breast cancer later in life.

Researchers with the Swiss Institute for Experimental Cancer Research found that prenatal BPA exposure alters long-term hormone response and breast development in mice that may increase the propensity to develop cancer.

They mimicked human exposure to BPA by adding the compound to the drinking water of breeding mice.

Female pups born to mice exposed to BPA were removed from the mother after weaning and followed. They had no further exposure to the chemical.

Researchers analyzed changes in the mammary gland of female offspring over time and found an increased response to the hormone progesterone in the mice exposed to BPA in the womb and during breast feeding.

Lifetime exposure to progesterone has been linked to increase breast cancer risk.

The mice also had a 1.5 fold increase in number of cells in the milk ducts.

Furthermore, the researchers found that adult females who had been exposed to BPA in utero and while breast fed, showed a 1.5 fold increase in cell numbers in their milk ducts.

The researchers, however, stressed that they did not find evidence BPA exposure causes breast cancer.

“We do provide evidence that BPA exposure alters mammary gland development and that this may increase the predisposition of the breast to breast cancer,” Cathrin Brisken, MD, of the Swiss Institute for Experimental Cancer Research and co-author of the study.

“While we cannot extrapolate these results directly from mice to humans, the possibility that some of the increase in breast cancer incidence observed over the past decades may be attributed to exposure to BPA cannot be dismissed,” she said.

“Our study suggests that pregnant and breastfeeding mothers should avoid exposure to BPA as it may affect their daughters’ breast tissue,” she added.

The study has been accepted for publication in Molecular Endocrinology. (ANI)