Understanding Obesogens

We blame weight gain on eating too many burgers and burning too little fat, but scientists are discovering that chemicals we’re exposed to everyday could be a big part of the obesity epidemic. Called obesogens, or endocrine disruptors, these natural and man-made chemicals work by altering the regulatory system that controls your weight—increasing the fat cells you have, decreasing the calories you burn, and even altering the way your body manages hunger.

 

It’s time to fight back. The White House's task force on childhood obesity is tackling obesogens and the Environmental Protection Agency has pumped $20 million into studying them. Here’s what you need to know to wage your own battle on the home front.

 

How they work

By mimicking the actions of naturally occurring hormones in our bodies or preventing the hormones we produce from acting correctly, endocrine disruptors can:

  • Encourage the body to store fat and re-program cells to become fat cells.
  • Prompt the liver to become insulin resistant, which makes the pancreas pump out more insulin that turns energy into fat all over the body.
  • Prevent leptin (a hormone that reduces appetite) from being released from your fat cells to tell your body you are full.

Where you find them

The short answer: everywhere, particularly because high fructose corn syrup, which can be found in every kind of food, from sodas to yogurt to pretzels, is an obesogen. The ubiquitous, viscous sweet stuff makes your liver insulin resistant and tampers with leptin to increase your hunger, setting up a vicious cycle where you crave more food that is then more easily turned into fat.

Other common places to find obesogens:

  • In your faucets: Pesticides seep deep into the soil and find their way to the water table and into your tap water. The main obesogen in tap water is atrazine. Banned in Europe, but found around the United States, atrazine slows thyroid hormone metabolism. Another culprit found in tap water, tributylin, a fungicide painted on the bottoms of boats, stimulates fat cell production.
  • Cans and water bottles: Bisphenol-A (BPA), a synthetic estrogen used to make plastics hard which has been banned from baby bottles, but is still present in many other plastics (especially sports water bottles) and the lining of most cans, has been shown to increase insulin resistance in animal studies.
  • Nonstick pans and microwave popcorn: Animal studies have shown that early exposure to a chemical used to make items non-stick – Perfluorooctanoic acid (PFOA) – leads to obesity in later life. It also is known to affect thyroid glands, which are important regulators of hormones that control weight. Found mainly in products like Teflon pans, it’s also hidden in microwave popcorn bags and pizza boxes.
  • Shower curtains and air fresheners: Phthalates, chemicals found in vinyl products such as shower curtains and fragrance products such as air fresheners, may lower testosterone and metabolism levels, causing you to gain weight and lose muscle mass. They’re also found in vinyl flooring and industrial-grade plastic wrap used to shrink wrap meat in the grocery store.

How to avoid obesogens:

  • Buy wild fish (such as salmon, which is packed with heart-healthy omega-3 fatty acids) and meat products that are hormone- and antibiotic free.
  • Install a granular activated carbon filter on your faucet to filter out chemicals such as atrazine.
  • Use aluminum water bottles or those that are BPA-free.
  • Steer clear of plastics with the number 3 or 7 on the bottom, which may leach BPA. Instead look for the numbers 1, 2, 4, 5, and 6, which are unlikely to contain BPA.
  • Keep water bottles cool (warm temperatures increase BPA leaching) and never microwave plastic.
  • Eat fewer canned foods. Opt for frozen or fresh instead. Tuna can be found in pouches that do not contain BPA.
  • Get rid of your non-stick pans if possible. If you must use a Teflon pan, never use a metal implement on it that can scratch the surface and release the chemicals inside, and throw away any scratched non-stick pans.
  • Buy meats straight from the butcher counter (instead of pre-packaged) and ask that they wrap them in brown paper.
  • Skip the air fresheners, open the windows, and try a vase of dried lavender instead.