A class of chemicals used for more than 60 years in products ranging from food wrappers to clothing to pots and pans may cause greater weight gain after dieting, particularly among women, according to research by Harvard T.H. Chan School of Public Health.
The chemicals—perfluoroalkyl substances (PFASs)—have been linked with cancer, hormone disruption, immune dysfunction, high cholesterol, and obesity.
The study also found that higher blood levels of PFASs—known as “obesogens” because they may upset body weight regulation—were linked with lower resting metabolic rate (RMR), or slower metabolism after weight loss. Metabolism refers to the chemical processes in the body that convert energy from food, commonly known as “burning calories.” People with a lower RMR, or slower metabolism, burn fewer calories during normal daily activities and may have to eat less to avoid becoming overweight.
The study was published online on February 13, 2018 in PLOS Medicine.
“Obesogens have been linked with excess weight gain and obesity in animal models, but human data has been sparse. Now, for the first time, our findings have revealed a novel pathway through which PFASs might interfere with human body weight regulation and thus contribute to the obesity epidemic,” said senior author Qi Sun, assistant professor in the Department of Nutrition at Harvard Chan School.
Studies have shown that PFASs have contaminated drinking water near industrial sites, military bases, and wastewater treatment plants. These chemicals can accumulate in drinking water and food chains and persist for a long time in the body.