Dust components may promote obesity

Dust bunnies that breed under furniture may be bad news for waistlines, a new study suggests. But it’s far too early to add dusting to a weight loss plan, researchers caution.

Components of indoor dust may signal human fat cells to grow and may alter metabolism, potentially contributing to weight problems, researchers report July 14 in Environmental Science & Technology.

“What that means to long term health and certain diseases, we don’t know yet,” says coauthor Heather Stapleton, an environmental chemist at Duke University. But, she says, the finding that dust contains bulge-inducing components, dubbed “obesogens,” raises the question of whether the contaminants play a role in the obesity epidemic.  

Stapleton and colleagues found that dust samples collected from homes and offices had components that activated a protein called PPAR-gamma1. This protein is found in many human tissues and, when switched on, can spur fat cells to grow. Researchers think it may be involved in obesity.

In lab tests with PPAR-gamma1-containing cells, the protein turned on in the presence of less than a milligram of some of the dust samples, the researchers found. Children may ingest around 50 milligrams of dust a day, the authors say.

As for culprit dust components, researchers first eyed common home contaminants such as flame retardants from furniture, some of which are suspected to activate PPAR-gamma1. But in a second study, also appearing online July 14 in the journal, the researchers found that fats, including oleic acid and palmitic acid, are mostly to blame. These compounds may come from cooking oils, shed hair or skin cells that have sloughed off humans and pets, the authors suggest.

“It is intriguing,” says Mitchell Lazar, director of the Institute for Diabetes, Obesity and Metabolism at the University of Pennsylvania. “But these findings need to be taken as very preliminary,” he says, adding that there are several caveats.

For one thing, we eat these fats in foods all the time, Lazar points out. “A 3-ounce portion of steak has 3 grams of oleic acid,” he says. “That is likely to be a lot more than would be consumed from indoor dust.”