Obesogens: An Environmental Link to Obesity

Image Gallery Prenatal and infant exposure to some chemicals in the environment can lead to obesity in adulthood. CHRISTOPHE B/FOTOLIA.COM

The herbicide atrazine is in the news for multiple reasons these days.  In addition to concerns that this widely used pesticide may cause cancer, evidence has recently surfaced showing that, for more than a decade, Syngenta has spent millions of dollars to pay scientists and journalists to deny and deflect the growing documentation of the human health dangers posed by atrazine. Plus, cancer is not the only concern with this chemical; a new report from the National Institute of Environmental Health Sciences names atrazine among a group of endocrine-disrupting chemicals that are “obesogens” — meaning they are suspected of contributing to the obesity epidemic now underway in this country. Here are links to these important stories: It's Time to Ban Atrazine, Syngenta Spends Millions to Deflect Evidence Against Atrazine Herbicide. — MOTHER

Obesity has risen steadily in the United States over the past 150 years,with a marked uptick in recent decades.  In the United States today more than 35 percent of adults  and nearly 17 percent of children aged 2 to19 years are obese.  Obesity plagues people not just in the United States but worldwide, including, increasingly, developing countries. Even animals — pets, laboratory animals, and urban rats — have experienced increases in average body weight over the past several decades, trends not necessarily explained by diet and exercise. In the words of Robert H. Lustig, a professor of clinical pediatrics at the University of California, San Francisco, “[E]ven those at the lower end of the BMI [body mass index] curve are gaining weight. Whatever is happening is happening to everyone, suggesting an environmental trigger.

Many in the medical and exercise physiology communities remain wedded to poor diet and lack of exercise as the sole causes of obesity. However, researchers are gathering convincing evidence of chemical “obesogens” — dietary, pharmaceutical, and industrial compounds that may alter metabolic processes and predispose some people to gain weight.

The idea that chemicals in the environment could be contributing to the obesity epidemic is often credited to an article by Paula Baillie-Hamilton, published in the Journal of Alternative and Complementary Medicine in 2002. Her article presented evidence from earlier toxicologic studies published as far back as the 1970s in which low-dose chemical exposures were associated with weight gain in experimental animals. At the time, however, the original researchers did not focus on the implications of the observed weight gains.