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Obesity: What do chemicals have to do with it?

Posted by SAFER States on Nov 21, 2011

Bruce Blumberg coined the term 'obesogens' and is considered to be one of the lead researchers on the subject. 'Diet and exercise are insufficient to explain the obesity epidemic, particularly the epidemic of obese six-month-old babies,' he says.

It's no secret that the United States is battling overwhelming issues with obesity. Current statistics show that 34% of Americans are clinically obese, and 68% are overweight1, and the federal government has found that a third of American children are obese or overweight.

This is having a tremendous consequence on the nation as a whole, including an estimated economic cost of $270 billion per year in the United States, according to a report2 released this year. The costs come in need for medical care and the loss of worker productivity due to death and disability.

So, as a society, we are tackling obesity in all the expected ways. We are encouraging adults and children alike to eat less, eat better, move more, and to live healthy lifestyles. We are reevaluating school lunch programs, insisting that fast food restaurants provide healthy options, and encouraging healthy decisions at every juncture.

But what if some chemicals we were exposed to every day were making us fat? Enter obesogens. Science has recently uncovered that exposure to certain chemicals sets the stage for obesity.

While obesity is a very complicated, multicausal issue, it is becoming increasingly clear that certain chemicals, dubbed obesogens, act upon genes in utero and may predispose some humans to becoming obese.

Bruce Blumberg, developmental biologist at University of California, Irvine, coined the term "obesogens" and is considered to be one of the lead researchers on the subject. "Diet and exercise are insufficient to explain the obesity epidemic, particularly the epidemic of obese six-month-old babies," he says3.

Last year, many scientists and medical doctors joined together to write a letter to First Lady Michelle Obama4 regarding her hard work to bring down obesity rates in the United States. Mrs. Obama has launched the "Let's Move" program5 which encourages children to eat healthily and get active to maintain a healthy weight. The letter to Mrs. Obama requested that the federal government take a holistic approach to obesity, acknowledge that chemicals are contributing to the obesity epidemic, and consider national chemical policy reform as an essential part of the campaign against childhood obesity.

Obesogens are quickly becoming a high priority among environmental advocates. Last month, our partner organization in Maine, the Environmental Health Strategy Center, hosted a conference focusing on chemicals and their role in obesity and diabetes. The conference included discussions of scientific studies supporting the obesogen hypothesis, and lectures by leading researchers including Dr. Blumberg, and Dr. Mark Mitchell whose work covers obesity In minority and low-income populations6.

Which chemicals are obesogens?

Some chemicals act as endocrine disruptors, which means that when they get in our systems they mimic or block hormones in the endocrine system, and interfere with the body's normal regulation of bodily functions. With regard to obesity, endocrine system hormones regulate hunger, fat storage, and the rate at which fat is burned—all important attributes which affect whether you gain or lose weight.

Bruce Blumberg's research7 indicates that obesogens can target the growth of a fetus and trigger more fat cells to be produced, setting the fetus up for a lifetime of body fat accumulation.

There are many ways that babies, children and adults are exposed to obesogenic chemicals, and most are chemicals that are commonly found in our households.

Bisphenol-A (BPA). A chemical that is ubiquitous and used to strengthen hard plastics, to make ink adhere to thermal receipt paper, and to coat metal food containers. Approximately six pounds of BPA are produced for every American per year8. It is an endocrine disruptor and has been tied to health effects including obesity and diabetes.

Phthalates. A group of chemicals that are used as plasticizers. They are found widely in our homes. Susan Freinkel, in her book Plastic: A toxic love story, lists out some of the places where phthalates are found:

"Phthalates have become so ubiquitous in consumer and industrial products that manufacturers make nearly half a billion pounds of them each year. They're used as plasticizers, lubricants, and solvents. You'll find phthalates in anything made of soft vinyl. But you'll find phthalates in other types of plastic and other materials too, in food packaging and food-processing equipment, in construction materials, clothing, household furnishings, wallpaper, toys, personal-care products such as cosmetics, shampoos, and perfumes; adhesives, insecticides, waxes, inks, varnishes, lacquers, coatings, and paints. They're even used in the time-release coating for medications and nutritional substances."

Phthalates are associated with health effects including lowered testosterone and lowered metabolism, which affect obesity rates.

Organotins. Used in several industrial applications, certain organotins are considered obesogens. In the past, some organotins were used as marine ship paints, and then leached into marine life, water, and was eventually ingested by humans. Their use in marine paint has been phased out, but "incompletely," according to some9. Additionally, organotins are used to make plastics, food packages, plastic pipes, pesticides and pest repellents10. It is thought that organotins interfere with the way that the body forms fat, and causes fat storage to be increased11.

Perfluorooctanoic acid (PFOA). Found in the environment, PFOA has been detected in household items such as non-stick cookware, stain resistant carpets, and microwave popcorn bags. A study12 in 2009 showed that low doses of in utero exposure to PFOA in mice resulted in overweight mice in mid-life.

There are other obesogens, and you can see that the breadth of their reach could be overwhelming to a mother who is trying to protect her children from harmful chemicals.

Janet Tauro, board chairman of the New Jersey Environmental Federation, the state chapter of Clean Water Action, and mother of two teenagers summarizes the pressure many parents feel:

"The most fundamental thing a parent can do is make your family home a safe and healthy place to be. That is becoming progressively difficult because so many products in our homes are filled with an alphabet soup of chemicals, even chemicals that are suspected of causing obesity. Shame on the chemical industry for foisting unnecessary chemicals on the American public and contributing to making our kids sick and obese."

We can't possibly expect individuals to be able to keep track of all the harmful chemicals, and how to avoid them. While in a reasonable scenario, we could expect the federal government to vet the chemicals that are in our homes, that is not happening.

The law that oversees chemical policies on a federal level is hopelessly out of date, and an overhaul of that law is stuck in a quagmire in Congress. This year, the Safe Chemicals Act was introduced into Congress which would help to modernize the Toxic Chemicals Safety Act (TSCA) and update it from its 1970s beginnings. The law is outdated enough that there is bi-partisan support for new legislation, and a hearing was held last week to help advance its passage. "I believe there has never been such broad agreement that TSCA needs to be fixed" said Ted Sturdevant, director of the Washington State Department of Ecology. "States are urging Congress to fix this law so we establish a strong federal system that ensures the safety of chemicals in commerce."

In the meantime, the states are taking over protection where possible.

Comprehensive policies can tackle new discoveries like obesogens

In the absence of proper oversight of chemicals, many states are taking a two-pronged approach to getting dangerous chemicals out of the lives of their residents:

  1. Banning the use of individual chemicals to get them out of our homes quickly. This has happened in many states with BPA, cadmium, and certain toxic flame retardants. Single-chemical bans are particularly helpful when the threat to our health and environment is clear, and public outcry about a chemical is loud.
  2. Passing comprehensive policies which take a more holistic approach to chemical use within a state, and affect the lifecycle of chemical use from manufacture to household use to disposal. While single-chemical bans are imperative in some situations, the chemical industry often abandons an outlawed chemical for an equally harmful one, causing environmental advocates to play whack-a-mole with laws, and to constantly be a step behind the chemical industry's games.

What we're learning from obesogens science, and other similar efforts, is that we need to build laws that are flexible enough to respond to new concerns with chemicals. Laws that can bend and adapt as emerging science pushes chemical understanding further, and as the chemical industry constantly innovates.

The best comprehensive laws in the nation:

Allow for constant evaluation of chemicals, and have a process for identifying the worst-of-the-worst chemicals. Several states now have policies in place to identify the worst-of-the-worst chemicals, and some states are working together, as it's not always feasible for an individual state to do the research for the state list.

For instance, Minnesota's "Toxic Free Kids Act," passed in 2009, required the creation of a "Priority Chemicals" list, and allowed for additions to the list dependent on work done by other state agencies including the California Environmental Protection Agency, the Washington Department of Ecology, the United States Department of Health, the United States Environmental Protection Agency, the United Nation's World Health Organization, and European Parliament Annex XIV.

By identifying a process for chemicals to be admitted on to priority lists, states are acknowledging the fluidity of chemical manufacture. "If one chemical is banned," says Kathy Curtis, the Executive Director of Clean and Healthy New York, "the industry moves a few molecules and calls it a new product." Priority chemical lists are better able to react when this occurs than are specific chemical bans.

Work hand-in-hand with manufacturers to phase the worst-of-the-worst chemicals out in favor of safer alternatives. States don't have the resources to determine safe alternatives for every harmful chemical that is in our households. So, the best comprehensive laws are creating mechanisms to work hand-in-hand with manufacturers to get harmful chemicals out in favor of safer alternatives. Maine's law has policies in place to require manufacturers to demonstrate alternatives to priority chemicals.

Create incentives for those manufacturers who are doing it right. Many states are discussing financial incentives for manufacturers who use safe alternatives to toxic chemicals. In 2010, Minnesota passed a policy which stated that companies who meet the definition of "green chemistry" (as defined in the Minnesota Toxic Free Kids Act) were eligible to access economic development programs.

Gather information about where chemicals are used, or require reporting of chemical use. Washington's Childrens' Safe Products Act, passed into law in 2008, will now require that any children's products containing any of the Chemicals of High Concern to Children13 be reported, beginning in 2012. This provides an incentive to manufacturers to get harmful chemicals out in lieu of safer alternatives before the reporting requirement begins, so that their products are not listed.

Consumers are starting to ask the hard questions about what's in our everyday products, and they are becoming less and less tolerant of the manufacturers' unwillingness to disclose ingredients. Laws like Washington's are acknowledging the need of consumers to have more information.

State chemical laws are not only helping the residents of the state where they are passed; they are sending a message to the federal government that it is possible to regulate chemicals in a successful way. As Delegate James Hubbard, a safe chemicals leader in Maryland, says, "When you start working at the state level then Congress sees that the legislation is possible."14

The passage of state chemical laws also sends a message to the chemical industry that the time for harmful chemicals in our household products is limited. It's becoming clear that chemicals have health effects that were never originally anticipated; obesity is having major repercussions on society as a whole, and it is imperative that we quash the role that toxic chemicals play on our weight, and the weight of our children.


1Endocrine disrupting chemicals and the developmental programming of adipogenesis and obesity. Birth Defects Research Part C: Embryo Today, March 2011.
2Cost of obesity approaching $300 billion a year. USA Today, January 12, 2011.
3Prenatal Exposures Prompt EPA to Re-examine Chemical Regulations New York Times, November 16, 2010.
4Letter to Michelle Obama. The Collaborative on Health and the Environment, March 29, 2010.
5Let's Move.
6Chemical Obesity Conference Proceedings. Colby College, October 14, 2011.
7Endocrine disrupters as obesogens. Molecular and Cellular Endocrinology, March 29, 2011.
8Chemical profile: Bisphenol A. ICIS, January 14, 2008.
9Identification of environmental obesogens or is the environment making us fat? Bruce Blumberg, PhD.
10Tins and compounds, ToxFAQs for Tin Agency for Toxic Substances & Disease Registry, August 2005.
11Enter the obesogen. The Economist, February 22, 2007.
12Phenotypic dichotomy following developmental exposure to perfluorooctanoic acid (PFOA) in female CD-1 mice: Low doses induce elevated serum leptin and insulin, and overweight in mid-life. Molecular and Cellular Endocrinology, May 25, 2009.
13The reporting list of chemicals of high concern to children. Department of Ecology, State of Washington.
14Our Heroes: Fathers, Grandfathers, Legislators. Safer States, July 7, 2011.