Bisphenol A, (BPA), a chemical found in a number of plastic products, can reduce the effectiveness of chemotherapy treatments on breast cancer, according to a study reported in the October 8, 2008 online edition of the journal Environmental Health Perspectives. Researchers at the University of Cincinnati subjected breast cancer cells to low levels of BPA, similar to levels found in the blood of humans. They found that BPA mimics estrogen, which can protect cancer cells from the effects of chemo, thus reducing chemo’s strength. Estrogen has been previously linked to chemotherapy resistance, but researchers have wondered why post-menopausal women can also be resistant. This study might provide some explanation for that connection. It might also be provide some answers for hormone receptor negative cancer.
BPA is found in drinking bottles and the lining of food cans. Some experts recommend avoiding plastic bottles marked with the recycling symbols 3,6 or 7. Others say all plastic, even that promoted as being BPA-free, is suspect and can leach dangerous estrogen-like chemicals.