There has been ongoing controversy in recent years surrounding the chemical bisphenol A, or BPA, a component of certain types of hard plastic containers and linings of metal cans in which food and beverages are sold. BPA has been identified as an endocrine disruptor, which means that it may mimic or amplify the effects of particular hormones in the body. The research on BPA has been mixed, but at one time or another it has been associated with heart disease, weight gain, cancer, and early onset of puberty in girls. More recently, BPA exposure during pregnancy was associated with restlessness and behavior problems in daughters later on. And now — not for the first time — a study has been released that links BPA to diabetes.
Published just over a month ago in the Journal of Clinical Endocrinology & Metabolism, the study examined the urinary BPA levels and diabetes status of adult participants in a wide-ranging national health data collection conducted between 2003 and 2008. According to a Reuters article on the study, of the almost 4,000 participants, the 25% with the highest levels of BPA in their urine had a diabetes rate of about 13%, while the 25% with the lowest levels of BPA had a diabetes rate of about 8%. This means that having higher BPA levels was associated with a diabetes rate 50% higher than having lower urine levels of the chemical.
As the study authors point out, this study does not provide conclusive evidence that BPA leads to diabetes. Even though the study controlled for traditional Type 2 diabetes risk factors among participants — including age, sex, race/ethnicity, body-mass index, and blood cholesterol levels — there may be factors unaccounted for in the study that could affect both BPA exposure and diabetes risk. For example, if certain people drink more soft drinks from cans that contain BPA, their increased sugar consumption — rather than their BPA exposure — might lead to a higher incidence of diabetes. A few animal studies have directly examined the effects of BPA exposure, but intentionally exposing humans to a potentially harmful chemical like BPA would be a breach of scientific ethics. Therefore, it is unlikely that there will ever be direct, clear evidence of harm caused by exposure to BPA.
What do you think — is the jury still out on BPA, or should the chemical be banned in food-related products? Do you avoid BPA by not using plastics with the recycling code “7″ (not all of which contain BPA), or by limiting your use of metal cans? Why or why not? Do you believe BPA might have been a factor in your developing diabetes? Leave a comment below!