Your New Year resolution might involve diet and exercise but according to news sources, that might not shrink your waistline. They say man-made chemicals called "obesogens" may be responsible for the "obesity epidemic," and regulators are gearing up to address this issue. Yet if people trust the hype, we can expect to become a fatter, less healthy nation.
In "Born to be Big," Newsweek reporters tell us "environmental chemicals may well account for a good part of the current epidemic." CBS's The Early Show reports "Chemicals in Food Can Make You Fat," and the United Kingdom's Mail Online reports: "Water CAN make you fat: How chemicals in drink[s] can trigger weight gain and fertility problems." Even diet and health gurus have jumped on the bandwagon, including TV personality Dr. Mehmet Oz. "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," reads Oz's website.
Obesogens are just one of the topics of study in a scientific field called "epigenetics." Epigenetics studies "gene expression" which involves changes to genes that don't affect underlying DNA sequence but do affect how genes eventually express themselves. It is an extremely fascinating and complicated field of research. Apparently, such changes can be passed from one generation to the next. "Environmental epigenetics" focuses on how chemicals might impact gene expression.
The term "obesogen" was coined by Biologist Bruce Blumberg, who has done some interesting research in this field on rodents. In the past, most researchers referred to these substances as endocrine-mimicking substances or "endocrine disruptors." The National Research Council uses a more neutral term: "hormonally active agents." Blumberg's terminology fuels media hype and further politicizes this body of research.
Not surprisingly, regulators at the U.S. Environmental Protection Agency (EPA) recently held a meeting on the issue to discuss "actions" (i.e., regulatory intrusions in the marketplace) they can take. Greenwire reports: "The researchers talked of chemicals that may be triggering the rise in obesity in the country; agents that promote cancer; and the need to quickly go through a list of about 200,000 chemicals in a European library of commercial compounds called REACH, to determine their toxicity." REACH stands for "registration, evaluation and authorization of chemicals" -- the name of a massively bureaucratic program in the European Union. The EPA wants Congress to use it as a model for revisions to the Toxics Substances Control Act -- and they even have started working on their version of the program while pushing for congressional authorization.
Chemical regulations won't reduce obesity, but they might contribute to the problem. Governmental and media hype under the rubric of "obesogens" sends the message that obesity is the result of forces beyond our control, reducing incentives for individuals to take control and responsibility with diet and exercise.
These individuals would be abandoning proven methods because of an unproven and unlikely theory. Medical researcher and obesity specialistDr. Randy Seeley -- explained to The Wall Street Journal that the research is too weak to draw conclusions. He echoes what scientific panels around the world have been saying about studies allegedly linking the chemical Bisphenol A (BPA) to obesity (for example, see page 30 of this National Institute of Health publication). BPA is used to make hard clear plastics and resins used in steel and aluminum food and beverage containers.
Chemist Joe Schwarcz of Canada's McGill University points out further that human exposure to man-made obesogens is too low to have any impact. In fact, if humans were at all sensitive to these agents we should fear very similar ones manufactured by Mother Nature. "Every day people are exposed to hundreds of thousands of natural and artificial chemicals which would show very similar effects if run through these sensitive tests," he told The Wall Street Journal.
Indeed, substances called phytoestrogens occur naturally in many foods and have the same endocrine-related effects, but we don't worry about them making us fat or sick. You will find them in fruits, vegetables and grains, and they are particularly concentrated in legumes, such as soy. As part of major review of the issue in 1999, National Research Council reported that daily exposure to phytoestrogens is tens of thousands of times higher than man-made chemicals, with an estimated daily total exposure of 1,000,000 micrograms per day (expressed as ug/d). Compare those levels to the just 6.3 ug/d from BPA in food cans. You can see the chart from this the National Research Council study online. For more details, see Nature's Hormone Factory and the listing this website.
Dr. Goutham Rao, MD of the Weight Management and Wellness Center at the Children's Hospital of Pittsburgh and author of Child Obesity: A Parent's Guide to a Fit, Trim, And Happy Child says that obesogens are low on his list of concerns. As a specialist helping children address obesity problems, his experience in the field proves that behavior modification (outlined in his book) that largely involves reducing consumption of high-calorie junk food and increasing physical activity is what works. His weight loss center also conducts examinations to identify any potential for endocrine-related or other biological explanations for each patient's obesity issue, but they rarely find such problems. The cause is usually clear: low activity levels and overeating.
Even if chemicals -- man-made or natural -- have an impact on weight, the impact is likely tiny, particularly compared to known factors related to weight gain: over eating and low activity levels. In fact, as the nation has grown fatter, it is no coincidence that portion sizes have grown larger. On the positive side, our weight problem reflects our growing wealth. We simply need to better manage our food consumption, which is something that only individuals -- rather than bureaucracies -- can do.
Image credit: Mike_fleming's flickr photostream.