Obesity and Chemicals: A Matter of Environmental Justice

Posted on March 11, 2010

By Jose Bravo

Childhood obesity has received a lot of media attention lately, but the solutions in the news focus just on personal responsibility. First Lady Michelle Obama’s Let’s Move initiative is a great start, but it only addresses eating healthy food and getting exercise. While personal responsibility is important, there are other underlying issues that contribute to the childhood obesity problem.

Scientific evidence shows that certain chemicals block our hormones and disrupt the body’s normal functions. Known “endocrine-disrupting” chemicals, this class of toxins includes PCBs, DDT, dioxin, some pesticides, and many plasticizers, like BPA. These chemicals play an important role in the global epidemic of obesity. Dr. Bruce Blumberg, professor of developmental and cell biology and pharmaceutical sciences at the University of California in Irvine believes there’s evidence that industrial pollutants are contributing to America’s obesity epidemic. Dr. Blumberg calls those chemicals “obesogens.”

“Despite what we’ve heard, diet and exercise alone are insufficient to explain the obesity epidemic.” —Dr. Bruce Bloomberg, UC Irvine

There is now strong evidence that our bodies mistake certain man-made chemicals used in plastics, food, wrappers, and fragrances, and many more items, for naturally occurring hormones that regulate the production and storage of fat cells.

“Evidence has been steadily accumulating that certain hormone-mimicking pollutants, ubiquitous in the food chain, have two previously unsuspected effects. They act on genes in the developing fetus and newborn to turn more precursor cells into fat cells, which stay with you for life. And they may alter metabolic rate, so that the body hoards calories rather than burning them…” —Retha Newbold of the National Institute of Environmental Health Sciences.

Endocrine-disrupting chemicals that may be linked to obesity include:

  • Bisphenol A (BPA) is ubiquitous in the environment. It is used to make polycarbonate plastic water bottles, baby bottles, the linings of metal food and soft-drink cans, thermal receipt paper, and dental sealants. Studies show that mice and rats fed low doses of BPA during early development became more obese as adults than those that weren’t fed the chemical. BPA leaches from food and beverage containers into what we eat and drink.
  • Phthalates are plasticizers found in PVC tubing, plastic, cosmetics, shampoos, soaps, lotions, lubricants, paint, pesticides, fragrances and more. One recent study linked a type of phthalate that leaches into processed food with abdominal obesity and insulin resistance in men.
  • Atrazine is a commonly used weed killer found to contaminate drinking water supplies, and exist as residue in food. After noticing an apparent overlap between areas where the weed killer is used and the prevalence of obesity, researchers conducted animal studies of the effects of low doses of atrazine. The findings suggest that atrazine may contribute to the development of insulin resistance and obesity, especially when the exposure is associated with a high-fat diet.
  • Perfluorooctanoic acid (PFOA) is used to make non-stick cookware, found in grease-proof food packaging, and stain-proof coating on clothing and carpeting. Several studies show that PFOA exposure results in reduced birth weight followed by weight gain after puberty.

You can learn more about chemical obesogens here:

José T. Bravo is Executive Director of the Just Transition Alliance based in Chula Vista, California.