Obesity is not only caused by diet and lack of exercise - forever chemicals may also play a part, Danish research shows.
Exposure to ‘forever chemicals’ could be contributing to obesity, a new study shows.
We all know that obesity is linked to what we eat and how much - or how little - we exercise. But chemical pollution could also be contributing to the deadly epidemic.
A Danish study published in the research journal, Obesity, on Monday exposes links between toxic PFAS - otherwise known as forever chemicals - and weight loss relapse.
What are 'forever chemicals' and why are they dangerous?
PFAS, or per- and polyfluorinated substances, are a large family of human-made chemicals. They are known as ‘forever chemicals’ because they don’t naturally break down in the environment.
The chemicals have been used since the 1940s for their non-stick, water-, heat- and stain-repellent properties. They are found in everything from clothing to non-stick pans and food packaging.
In recent years, PFAS have been linked to serious health issues, including birth defects and cancer. This has led to stricter regulations and phaseouts of PFAS, yet some are still dubiously deemed safe for use - despite some research showing that approved chemicals can leak from packaging into our food.
How are forever chemicals linked to obesity?
Scientists from the University of Southern Denmark and the University of Copenhagen set out to study the impact of PFAS exposure on body weight.
They used data from a 2011 trial that examined the link between various diets and cardiovascular risk.
The original study included participants with obesity from eight European countries: Bulgaria, the Czech Republic, Denmark, Germany, Greece, Netherlands, Spain and the United Kingdom.
After being tasked with losing eight per cent of their body weight, they were randomly placed in five different diet groups, some of which aimed to induce weight loss, for a 26-week period.
The Danish researchers examined the levels of five types of PFAS in the plasma of 381 of these participants.
They found significant links between weight increase and chemical levels, regardless of diet. Two groups of the chemicals - PFOA and PFHxS - almost doubled in line with a weight gain of 1.5 kg across all diet groups.
Weight gain associated with PFAS exposure was also found to be more significant than weight gain linked with suboptimal diets.
Exposure to certain environmental toxins could therefore explain the variable success of some diets, such as low-carb diets.
Previous studies have shown that PFAS can alter energy metabolism, glucose control and thyroid hormone homeostasis - all of which have implications for weight.
Is obesity a big problem in Europe?
Obesity brings its own back catalogue of health problems. In Europe alone, it is causing at least 200,000 cancer cases and 1.2 million deaths a year - making it the continent’s fourth biggest killer - according to a 2022 report by the World Health Organization (WHO).
Almost a third of children and 59 per cent of adults in Europe are overweight or living with obesity, the report said.
Europe's rates of obesity are higher than any WHO region other than the Americas, the UN body said, adding that they rose 138 per cent between 1975 and 2016.