KINGSTON, R.I. — A University of Rhode Island researcher led a study that confirms a direct link between certain chemicals in drinking water and human obesity. It specifically found that increased per- and polyfluoroalkyl substances (PFAS) content in blood promotes weight gain and makes it harder to keep a lower body weight after weight loss.

Dr. Philippe Grandjean holds a research professor appointment within the URI College of Pharmacy and serves on Sources, Transport, Exposure & Effects of PFAS (STEEP) — a URI-led science effort helping the public grapple with PFAS pollution, including its presence in drinking water resources.

STEEP researchers have linked these human-made chemicals to thyroid disease, low birth weight, cancer, and cardiovascular disease.

“We’ve previously shown that children with increased PFAS concentrations tend to gain weight and develop higher levels of cholesterol in the blood,” said Grandjean, a professor of environmental medicine at the University of Southern Denmark, who has researched the human health impacts of PFAS in multiple countries and populations, including children, for decades. “We now focused on adults who participated in an experimental study of five different diets in regard to weight gain. Our results add to the concern that environmental pollution may be affecting our metabolism.”

For the recent study, the researchers, using STEEP-affiliated laboratories, analyzed PFAS chemicals in 381 blood samples that were already part of a randomized European Commission clinical trial in Europe focused on weight loss planning for obese adults. No matter the diet that these participants were assigned to, they gained weight if they had elevated PFAS exposures, the researchers found.

One particular chemical, perfluorooctanoic acid (PFOA), which is commonly found in contaminated drinking water, demonstrated, more so than other PFAS pollutants, ties to obesity. Furthermore, those participants in the European study with the most PFOA in their blood were found, after a one-year follow-up, to have gained about 10 pounds more than those with low levels.
 
“Our study adds new evidence that being overweight isn’t just about a lack of physical activity and unhealthy eating habits — PFAS are increasingly suspected to be a contributing factor,” Grandjean said.

PFAS, a large and decades-old family of chemicals, infiltrate many human and natural environments, according to Rainer Lohmann, a URI chemical oceanographer and STEEP research director.

PFAS chemicals are colorless, tasteless, and odorless, and often are used to create barriers or stop liquids from seeping. The chemicals coat pizza boxes and microwave popcorn bags, nonstick cookware, and waterproof clothing, and stop stains from sinking into carpet and furniture.
 
These heavily used “forever chemicals” have also leached into water, from marine habitats to drinking water resources. A team of researchers, including Lohmann, have found PFAS contaminants in the Arctic marine food web.

“The hard science is the main tool the government has upon which to make changes that move us closer to either lessening or removing PFAS from our water, our lives, our environments,” Lohmann said.