A panel of university-based scientists convened by The Endocrine Society recently reviewed the available literature on health effects of endocrine-disrupting chemicals (aka EDCs). The executive summary is available free online. Some excerpts:
The full Scientific Statement represents a comprehensive review of the literature on seven topics for which there is strong mechanistic, experimental, animal, and epidemiological evidence for endocrine disruption, namely: obesity and diabetes, female reproduction, male reproduction, hormone-sensitive cancers in females, prostate cancer, thyroid, and neurodevelopment and neuroendocrine systems. EDCs such as bisphenol A, phthalates, pesticides, persistent organic pollutants such as polychlorinated biphenyls, polybrominated diethyl ethers, and dioxins were emphasized because these chemicals had the greatest depth and breadth of available information.
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Both cellular and animal models demonstrate a role for EDCs in the etiology of obesity and T2D [type 2 diabetes]. For obesity, animal studies show that EDC-induced weight gain depends on the timing of exposure and the age of the animals. Exposures during the perinatal period [the weeks before and after birth] trigger obesity later in life. New results covering a whole range of EDC doses have underscored the importance of nonmonotonic dose-response relationships; some doses induced weight increase, whereas others did not. Furthermore, EDCs elicit obesity by acting directly on white adipose tissue, al- though brain, liver, and even the endocrine pancreas may be direct targets as well.
Regarding T2D, animal studies indicate that some EDCs directly target beta and alpha cells in the pancreas, adipocytes, and liver cells and provoke insulin resistance together with hyperinsulinemia. These changes can also be associated with altered levels of adiponectin and leptin— often in the absence of weight gain. This diabetogenic action is also a risk factor for cardiovascular diseases, and hyperinsulinemia can drive diet-induced obesity. Epide- miological studies in humans also point to an association between EDC exposures and obesity and/or T2D; however, because many epidemiological studies are cross-sectional, with diet as an important confounding factor in humans, it is not yet possible to infer causality.
Bix at Fanatic Cook blog says foods of animal origin are the major source of harmful persistent organic pollutants, some of which act as ECDs.
Keep your eyes and ears open for new research reports on this critically important topic.
Steve Parker, M.D.