Offspring of Mothers Exposed to Lead Face High Risk of Obesity

Mice born to mothers exposed to lead, even at low levels, face a high risk of obesity, a new study reveals.

Exposure to lead generally causes neurological problems. But in the latest study, researchers at the University of Michigan highlighted another health impact, obesity, on exposure to the chemical element. Male mice exposed to lead had 8-10 percent greater risk of gaining weight.

"The data support the obesogen hypothesis that toxicant exposures in the womb contribute to the higher rate of obesity," said Dana Dolinoy, the John G. Searle Assistant Professor of Environmental Health Sciences and senior author of the study. "There are certain chemicals that are considered the hallmarks of the obesity epidemic, and lead has not been one of them."

This is the first study that highlights how exposure to lead even before pregnancy can impact the health of the offspring. Previous studies revealed how exposure to lead was associated with decreased fetal and early childhood growth in human infants and obesity in mice in later life.

In the current study, the researchers exposed the mother to lead through drinking water. This was done two weeks before they were made to mate. They were exposed to lead at 0.0 parts per million for the control group 2.1 ppm, 16 ppm or 32 ppm.

They tested the maternal blood lead levels at weaning. The lead levels were below that of the detection of control group. According to the Centers for Disease Control and Prevention, 5 μg/dL is listed as the reference level to trace children who are exposed to lead and require management.

It was noticed that males in groups with highest exposure weighed more than the controls and the trend was same from youth to adulthood. Males, when 3 months of age, showed increase in body fat. These males even showed impaired levels of insulin at 9 months of age. Though females were more active there was no increase in activity for either sex.

Lead present in air, water, soil, food and consumer products is found to have detrimental effects of health. The use of these chemicals in paint and gasoline is banned.

The finding was documented in PLOS One.