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Researchers find connection between PFAS exposure and overweight

A new study finds that an increased PFAS content in blood promotes increases body weight and especially added difficulty in maintaining a lower body weight after weight loss.

By Marianne Lie Becker, , 4/19/2023

Under the leadership of Philippe Grandjean, MD, professor of environmental medicine at the University of Southern Denmark, a group of scientists examined blood samples from 381 adults who participated in a clinical trial supported by the European Commission.  

They found that adults with an elevated concentration of a common PFAS called PFOA in their blood put on weight no matter which diet that they followed in the clinical trial.  

PFAS are often found in contaminated drinking water and foods. 

Previously found in children 

The study showed that participants with the highest amounts of PFOA in the blood after a follow-up lasting up to one year had the greatest difficulty in keeping a lower body weight, in fact, they had gained an average of about ten pounds during the 52 weeks, as compared with those with the lowest exposure.  

- We have previously shown that children with elevated PFAS in the blood have a tendency of gaining weight and developing higher cholesterol levels in the blood, says Philippe Grandjean who has studied PFAS toxicity in humans, including children in various countries during the last 15 years.  

- In the new study, we focused on adults who participated in a clinical trial of the impact of five different diets on body weight, and in particular in preventing weight gain after an initial weight loss. It turned out that PFAS had a greater impact than diet. 

Obesity is not solely caused by diet and inactivity

The results increase the concern that environmental pollutants can affect metabolic functions of the body so that we have an increased tendency of gaining weight.  

- Our study adds new evidence that overweight is not just due to lack of physical activity and unhealthy eating habits – PFAS is increasingly suspected of being an additional factor, says Philippe Grandjean.  

Our study adds new evidence that overweight is not just due to lack of physical activity and unhealthy eating habits – PFAS is increasingly suspected of being an additional factor

Philippe Grandjean, professor

Arne Astrup, professor at the Novo Nordisk Foundation and CEO of its Department of Obesity and Nutrition, was the leader of the European project Diogenes, from which the blood samples and data in the new study are derived. 

He believes that the reason why more and more people overeat and develop obesity is poorly understood, and that we must acknowledge that endocrine-disrupting chemicals such as PFOA in our environment may very well have a harmful impact on the body's appetite regulation and therefore be a contributing factor to overweight and obesity. 

- It is incredibly important to identify such factors, as this new knowledge can help destigmatize people living with severe obesity. There is now yet another good reason for an effective effort to reduce or eliminate PFAS from our environment, says Arne Astrup. 

Need for information about “forever chemicals” 

PFAS is a large and decades-old family of industrial chemicals that accumulate in humans and environments.

They are colorless, tasteless, and odorless and are often used to protect kitchenware, textiles, and other consumer products and to prevent stains from discoloring carpets and furniture. These chemicals have also been commonly used in firefighting foams. 

The substances are almost non-degradable and are therefore often referred to as "forever chemicals". They have also reached groundwater, the world's oceans, and are polluting food chains.

That's why the American STEEP research center at the University of Rhode Island, where Grandjean is part of the leadership, is committed to ensuring that sound science contributes to informing public dialogue about improving the protection of citizens against these toxic substances. 

Hope for new guidelines 

- At the international level, the discussion mainly focuses on legislating limit values and finding ways to regulate the content of PFAS in drinking water. But we are exposed to PFAS in many ways, and probably most of all through the diet, says Philippe Grandjean. 

The European Commission is working on a proposal to ban PFAS in consumer products, and the US Environmental Protection Agency has recently proposed binding guidelines for water pollution. 

- I hope that the new measures will be successful, and now I have an additional reason to hope, he says. 

The study has just been published in Obesity, read more here.



Meet the researcher

Philippe Grandjean is Professor of Environmental Medicine at the Department of Public Health. His many years of research have made him a well-known figure in the public eye on topics such as mercury in fish, men's sperm quality, asbestos, pesticides, hormone disruption, and more recently, especially PFAS.


Editing was completed: 19.04.2023