Bisphenol A (BPA) is a colorless synthetic organic compound that is used in the production of polycarbonate plastics and epoxy resin, so it doesn’t sound like something that could contribute to obesity. Yet BPA could be a factor in making you put on extra pounds. Can BPA make you fat?
How can BPA make you fat?
BPA is chemically similar to 17-beta-estradiol, a type of estrogen, which means it can attach itself to estrogen receptors. This activity can promote inflammation, oxidative stress, adipogenesis (a process that is involved in the production of fat cells), malfunction of pancreatic beta cells, and insulin resistance, all factors that can contribute to weight gain.
Research into how can BPA make you fat has been going on for years. In 2011, for example, experts evaluated data from 2,747 adults to identify the effects of BPA on overweight and obesity (a body mass index [BMI] of 25 to 29 and greater than 30, respectively). They found that in general, there was an association between high BPA levels in urine samples and greater BMI.
In addition, people with greater BPA levels also had a larger waist circumference and a greater chance of being classified as abdomanally obese when compared with people who had the lowest BPA levels. Although these factors were seen in both men and women, the associations were greatest in men.
In a 2009 study involving 2,581 adults, the authors found BPA in 78.1 percent of serum samples. The BPA levels were higher among people with diabetes and those who had impaired fasting glucose levels when compared with individuals who had normal blood glucose levels. BPA levels were also more elevated in men than in women.
How are you exposed to BPA?
Most people are exposed to BPA through food and food packaging, such as the lining of some cans and by drinking water or other beverages from plastic bottles. Although some manufacturers have replaced BPA with BPS, the latter chemical has been found to pose health issues similar to the former.
Other ways people come in contact with BPA is with thermal paper (e.g., cash register receipts), polycarbonate tableware, microwave-safe plastic containers, and plastic products marked with the numbers 3 or 7 (both of which may or may not contains BPA).
Exposure to BPA via thermal paper (e.g., cash register receipts, ATM receipts, airline tickets) is of special concern. A 2014 study, for example, showed that the combination of using hand sanitizer and touching cash register receipts significantly increases the absorption of BPA through the skin. In fact, use of other skin care products that contains a mixture of chemicals (such as those that boost penetration; think hand lotions, sunscreen) may also increase absorption of BPA. Researchers found that holding a receipt containing BPA for 45 seconds immediately after applying hand sanitizer resulted in maximum absorption of the chemical, while holding the receipt for 2 or 15 seconds caused absorption of 40 percent and 58 percent of maximum, respectively. Individuals who did not use hand sanitizer before handling cash register receipts still absorbed BPA, but at a lower level.
The best way to avoid BPA is to eliminate plastic products from your life as much as possible, refuse cash register receipts whenever you can (you also can ask for an email receipt if you need one), and steering clear of canned foods.
Aekplakorn W et al. Relationship of serum bisphenol A with diabetes in the Thai population, National Health Examination Survey IV, 2009. Journal of Diabetes 2015; 7(2): 240-49
Carwile JL, Michels KG. Urinary bisphenol A and obesity: NHANES 2003-2006. Environmental Research 2011: 111(6): 825-30
Hormann A et al. Holding thermal receipt paper and eating food after using hand sanitizer results in high serum bioactive and urine total levels of bisphenol A (BPA). PLoS One 2014; 9(10): e110509
Ranciere F et al. Bisphenol A and the risk of cardiometabolic disorders: a systematic review with meta-analysis of the epidemiological evidence. Environmental Health 2015; 14:46