Exposure to dioxins during pregnancy harms the cells in rapidly-changing breast tissue, which may explain why some women have trouble breastfeeding or don't produce enough milk, according to a University of Rochester Medical Center study.
Researchers believe their findings, although only demonstrated in mice at this point, begin to address an area of health that impacts millions of women but has received little attention in the laboratory, said corresponding author B. Paige Lawrence, Ph.D., associate professor of Environment Medicine and of Microbiology and Immunology at URMC.
"Estimates are that three to six million mothers worldwide are either unable to initiate breastfeeding or are unable to produce enough milk to nourish their infants," Lawrence said. "But the cause of this problem is unclear, though it has been suggested that environmental contaminants might play a role. We showed definitively that a known and abundant pollutant has an adverse effect on the way mammary glands develop during pregnancy."
Dioxins are generated mostly by the incineration of municipal and medical waste, especially certain plastics. Most people are exposed through diet. Dioxins gets into the food supply when air emissions settle on farm fields and where livestock graze. Fish also ingest dioxins and related pollutants from contaminated waters. When humans take in dioxin most often through meat, dairy products, fish and shellfish the toxin settles in fatty tissues; natural elimination takes place very slowly. The typical human exposure is a daily low dose, which has been linked to possible impairment of the immune system and developing organs.
In 2004 Lawrence's laboratory made the novel discovery that dioxin impairs the normal development of mammary glands during pregnancy. However, the underlying mechanisms were unclear, as was the extent of injury and whether exposure during certain stages of pregnancy had more or less of an impact on milk
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University of Rochester Medical Center