“Perfectly Safe” Pesticide Linked to Obesity Epidemic
New research suggests that exposure to the banned pesticide, DDT, may be linked to the growing obesity epidemic. Scientists at the University of California, Davis, reported recently that female mice that are exposed to the pesticide during the developmental stages later experienced a significantly greater risk of developing the metabolic syndrome. The metabolic syndrome is a constellation of disorders and health conditions, including obesity, high blood pressure, high blood sugar levels and high blood cholesterol. People with the metabolic syndrome are at greater risk for heart disease and premature death.
Mice exposed to DDT in the womb experienced alterations in their metabolism. In effect, their metabolisms slowed, making it more likely that they would store fat, and rendering them less able to counteract the effects of exposure to cold temperatures.
Although DDT was banned in the 1970s, many women who were pregnant in the 1950s were exposed to the pesticide. It was used extensively throughout parts of the United States in an effort to eradicate mosquitos and other pests. At the time it was claimed that the chemical was perfectly safe. But in 1962, Rachel Carson published her groundbreaking book, "Silent Spring," about the pesticide's devastating effects on songbirds and other wildlife in America. The pesticide persists in the environment for many years, and accumulates in a wide range of living creatures. By the early 1960s it had severely affected birds' ability to lay eggs with sufficiently strong shells. The iconic American Bald Eagle nearly went extinct as a result.
Adults whose mothers were pregnant in the 1950s are now reaching the age when the metabolic syndrome is most common. This new research suggests that women born in the period are especially at risk for excess weight gain and altered metabolic function. "The women and men this study is most applicable to in the United States are currently at the age when they're more likely to develop metabolic syndrome, because these are diseases of middle- to late adulthood," said lead author Michele La Merrill, assistant professor of environmental toxicology at UC Davis. DDT is still used in certain developing countries to control mosquitos and the diseases they harbor.
Michele La Merrill, Emma Karey, Erin Moshier, Claudia Lindtner, Michael R. La Frano, John W. Newman, Christoph Buettner. Perinatal Exposure of Mice to the Pesticide DDT Impairs Energy Expenditure and Metabolism in Adult Female Offspring. PLoS ONE, July 30, 2014 DOI: 10.1371/journal.pone.0103337