Avoid Bisphenol-A (BPA) for a better body composition and less risk of disease. BPA mimics the hormone estrogen in the body and a notable new study found a direct association between urinary BPA levels and obesity risk in a large multi-ethnic population. This study shows BPA makes both men and women fat, and that it affects all races.
BPA is a chemical that is used to make plastic, line the inside of food cans, and it functions as an epoxy resin, coating everything from medical equipment to receipt paper. When it enters the body it mimics the hormone estrogen and binds to estrogen receptors. Because the body always tries to achieve homeostasis, any time one hormone is altered it affects the levels of other hormones, meaning that greater BPA exposure doesn’t just increase your estrogen levels—it can influence the function of everything from testosterone to insulin.
For example, there’s evidence that BPA exposure decreases reproductive function, increases heart disease risk, causes inflammation, affects brain function, and causes hyperactivity in children. In one study, BPA exposure in young girls was linked to behavior problems such as ADHD-like symptoms. And a 10-year study found that subjects who had increasing urinary BPA concentrations over the study period had much greater risk of heart disease, after adjusting for confounding factors.
The new report in the International Scholarly Research Network-Endocrinology found that in 4,792 Americans, greater urinary BPA levels were associated with much greater risk of obesity as defined by BMI and waist circumference even after adjusting for factors such as smoking, alcohol intake, physical activity, education, and race. The study broke urinary BPA levels into quartiles and found that there was an across the board increased risk of obesity with higher levels of urinary BPA. This means that in every subgroup (gender, race, age, education level), rates of obesity increased with more BPA exposure.
For example, people who had more than 4.20 ng/ml BPA in their urine had at least a 34 percent chance of being obese compared to those with less than 1.10 ng/ml BPA who only had a 23 percent chance of being obese.
Researchers think that greater BPA exposure increases body fat because it alters insulin sensitivity, affects metabolism, causes inflammation, and decreases levels of a hormone called adiponectin that regulates fat burning.
For tips on how to avoid BPA and other chemical estrogens, please read Ten Things You Can Do To Limit Chemical Estrogen Exposure.
Melzer, D., Osborne, N., et al. Urinary Bisphenol a Concentration and Risk of Future Coronary Artery Disease in Apparently Healthy Men and Women. Circulation. 2012. 125(12), 1482-1490.
Shankar, A., Teppala, S., et al. Urinary BPA Levels and Measures of Obesity: Results from the NHANES 2003-2008. International Scholarly Research Network-Endocrinology. 2012. Article ID 965243.