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New Research Links BPA to Breast Cancer in Lab Animals, FDA Downplays Concerns
New federally funded research links low doses of bisphenol A with a sharp increase in breast tumors in laboratory animals. But the Food and Drug Administration continues to insist on the safety of BPA, a compound used widely in plastic, metal food cans and receipt paper.
Today, an independent peer review panel will meet to assess the first results of a two-year study funded by the National Institutes of Health. The most important finding was a threefold increase in combined cancerous and benign breast tumors in rodents who were given very small doses of BPA. The study also found other significant effects on the heart, and on the male and female reproductive systems.
Yet a month before the panel is scheduled to meet, the FDA issued a statement asserting that the study found “minimal” effects. This has been the FDA’s posture for more than a decade: defending the safety of BPA exposures while independent scientists report BPA is toxic to the brain, thyroid and reproductive systems.
Scientists involved in the study have levied sharp criticism at the FDA for drawing premature conclusions from incomplete data.
“FDA’s data show significant effects at low doses, particularly in mammary glands,” Heather Patisaul, a professor of biological science at North Carolina State University, told EWG. “But instead of acknowledging this, they use analytical tricks and reasoning not supported by modern science to explain these effects away and undermine their own findings. Clearly this is not in the interest of sound science or public health.”
Starting in 2010, the FDA partnered with the National Institute of Environmental Health Sciences, as well as 14 independent researchers, in a massive safety study known as CLARITY-BPA. The goal was to reach a clear conclusion about BPA safety and the proper methods for studying hormone-disrupting chemicals. The FDA’s part of the study followed longstanding guidelines for safety testing, while the academic investigators ran tests they believed could reveal more sensitive indicators of harm.
Today’s review panel will not consider the results of 10 peer-reviewed studies already published by academic researchers, nor dozens of upcoming academic publications. These studies undercut the FDA’s assurance of BPA safety. For example:
- A 2017 study from North Carolina State University found that prenatal BPA exposure affects the expression of genes in the amygdala, a part of the brain responsible for emotions. This may help to explain the results of human studies that link higher prenatal BPA exposure to behavior problems like anxiety, depression and hyperactivity in children.
- University of Cincinnati researchers reported in 2017 that BPA exposure impairs the ability of the heart muscles to pump blood. This effect was also observed in the FDA arm of the CLARITY study.
- Researchers at the University of Missouri at Columbia reported in 2015 that for female rats, prenatal exposure to BPA impaired learning and memory.
- Researchers at the University of Illinois at Urbana-Champaign reported in 2017 that BPA exposure affects the level of sex steroids and the number of ovarian follicles, which hold immature eggs.
Future publications are expected to examine the risk that BPA causes obesity, diabetes, prostate cancer, breast cancer and thyroid problems.