Dioxin exposure during pregnancy impairs the development of mammary glands during pregnancy and may cause women to not produce enough milk for their newborns, a new study finds.

Breast milk is an amazing food for babies, and breastfeeding has many benefits for both mother and child, including reducing the risk of heart attacks for mothers, reducing asthma risks for babies, and reducing anxiety in children. But up to 6 million women either can’t breastfeed, or don’t produce enough milk for their child, and dioxin in our food chain may be to blame.

The study, from the University of Rochester Medical Center, found that dioxin causes mammary cells to stop their cycle of proliferation as early as six days into pregnancy, and the effects of exposure can last through mid-pregnancy.

“We showed definitively that a known and abundant pollutant has an adverse effect on the way mammary glands develop during pregnancy.” – B. Paige Lawrence, Ph.D., associate professor of Environment Medicine and of Microbiology and Immunology at URMC

Human exposure to dioxins is usually through diet, as the chemical enters the food chain through emissions settling on farmland, and through livestock and fish. Though normal exposure is in typically low daily doses, the toxin settles in the fatty tissues and is slow to be eliminated.

Researchers found that in tissue samples from mice, a 50% decrease in new epithelial cells was seen after dioxin exposure, and because mammary gland cells have a high rate of growth during early to mid-pregnancy, this is an important finding. The team also reported that dioxin alters the induction of the milk-producing genes and reduced the number of lobules and ductal branches in mammary tissue.

“The best thing people who are concerned about this can do is think about what you eat and where your food comes from. We’re not suggesting that we all become vegans — but we hope this study raises awareness about how our food sources can increase the burden of pollutants in the body. Unfortunately, we have very little control over this, except perhaps through the legislative process.” – Lawrence

The report was published online in Toxicological Sciences. The group is also investigating a possible link between breast cancer and dioxin exposure.

Image: Daquella manera at Flickr under CC license

