Chemicals used in food wrappers, non-stick pan coatings and clothing may boost body weight by interfering with metabolism, according to a study led by Harvard T.H. Chan School of Public Health.
These chemicals, known as perfluoroalkyl substances (PFASs), have previously been linked with cancer, hormone disruption, immune dysfunction, high cholesterol and obesity.
“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.
PFASs are chemicals with commercial and industrial uses, found in everything from food packaging to textiles. Perfluoroalkyl substances (PFASs) are also found in water-repellent clothing, stain-resistant fabrics and carpets and cosmetics.
They can be ingested or inhaled and absorbed into the bloodstream, but are not able to be metabolized or broken down in the body. PFASs also have the potential to bioaccumulate and biomagnify through the food chain, previously being detected in fish and birds.
Harvard University analyzed 621 obese and overweight people over two years as they attempted to diet. Women with the highest PFAS levels gained about 2 kg more than those with the lowest levels of PFASs.
Upon closer investigation, the researchers found that those with PFAS levels in their blood also burned calories slower, having a lower resting metabolic rate.
“We typically think about PFASs in terms of rare health problems like cancer, but it appears they are also playing a role in obesity, a major health problem facing millions around the globe,” said study co-author Philippe Grandjean.
“The findings suggest that avoiding or reducing PFAS exposure may help people maintain a stable body weight after they successfully lose some weight, especially for women.”
The Harvard team suggested PFASs may be slowing down metabolism, which makes it harder to lose weight. The study was published in the journal PLOS Medicine.