EHSC Blog

The Science Behind the Obesity Epidemic

We all accept that certain medications make people gain weight: it’s true of antidepressants and birth control pills, for example. But what if you could gain weight simply by being exposed to the chemicals found in everyday products, like plastic food containers, shower curtains, and the residues from pesticides in fresh fruits and vegetables?

At the Chemicals, Obesity and Diabetes conference at Colby College last Friday, co-sponsored by EHSC, I learned that scientists are finding more and more evidence that this indeed is the case. Dr. Bruce Blumberg, a scientist at the University of California-Irvine, studies a class of chemicals called organotins, and one in particular called Tributyltin, which is used in various industrial applications as a fungicide. In experiments on mice in utero, he found that exposure to Tributyltin can actually cause changes in the animals’ genes. Cells that might have turned into bone became fat cells instead. Not only that, this change in DNA can be passed down for generations to come. No, this isn’t science fiction. Unregulated chemicals in the marketplace are setting kids up to be obese before they’re even born. Blumberg calls these chemicals obesogens.

“Diet and exercise are insufficient to explain the obesity epidemic, especially in the young,” he said. After all, babies and young children get plenty of exercise by default, and they generally don’t overeat. But babies and children are still at risk of obesity because these chemicals (also known as endocrine disruptors) cause the most damage during fetal development, early infancy, childhood, and puberty.

I should pause here to point out that weight gain isn’t the only issue of concern–it’s just the most visible marker of how environmental chemicals are changing our physiology on the cellular level. Less obvious to the casual observer are the other chronic health problems affecting children today, like diabetes, asthma, and early puberty–all of them diseases of the same bodily systems that we know chemicals act upon.

The Unregulated Marketplace

In his panel discussion with Richard Denison, a Senior Scientist at the Environmental Defense Fund, EHSC Director Mike Belliveau stated that more than 62,000 chemicals that are on the market have been “grandfathered in” to be exempt from current chemical regulations. He also said that 85% of new chemicals that go under review in front of the EPA have no health data associated with them. That means the EPA has no way of knowing how to determine their toxicity without conducting their own studies, which they do not have the time or means to do. The result? Of the 80,000 or so chemicals found in commerce today, roughly 200 have been tested for safety before ending up on the market, and the EPA is unable to address this overwhelming problem.

If the EPA can’t determine how chemicals may affect our kids’ health, how are consumers supposed to figure it out? Through trial and error? I had a boss once, a somewhat mad scientist, who said (only half-jokingly) that she hoped to have identical twins one day, so she could perform case/control studies on them. While I laughed at her remark then, I’m sad to say that it’s beginning to seem as though we are all unwitting scientists, subjecting our kids to a grand experiment in which we have no idea what the dose or even the poison is.

What We Can Do

So what can parents and consumers do to protect children? As Dr. Blumberg said, “We can take our own steps to minimize exposure. Buy organic, avoid plastic.”

If you’re like me, you probably already try to do this. I try to buy organic fruits and vegetables, but as a mom of two on a budget, it’s difficult. To keep myself focused, I use the Environmental Working Group’s Dirty Dozen as a guideline. I always buy organic spinach, for example, but avocados get a pass due to their thick skins. And while I do still use plastic containers for storing dry foods, I try to put hot food in a glass container before it goes in the fridge. And of course I never, ever microwave anything made of plastic. I also make sure that if I send a lunch to my kids’ daycare that needs to be heated, I send it in a glass container. The caregivers there already know they shouldn’t microwave plastic, but why give them an extra step in their busy days?

Which brings me to my final take away message from the conference: the burden shouldn’t be on us, the parent and consumers, to keep kids safe. Companies should be responsible for what they put out into the marketplace. That’s why the Safe Chemicals Act of 2011 is so important. It will require chemical manufacturers to demonstrate that their products are safe, and provide safety data to the government and other businesses. And until that day when companies regulate themselves, we’ll have to do it for them. We can refuse to buy products from companies that use BPA and phthalates and Tributyl-tin in their products. Then we can write to those companies and tell them why we have stopped buying their products. I learned at the conference that this is called “retail regulation,” and right now, it might be our best defense against a toxic world while we push for real policy reforms.

Written by Reeve Chace, a mom and volunteer with EHSC

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