Chemicals found in fast food packaging and a wide variety of other consumer products could cause weight gain by crushing metabolism, particularly in women, new research claims.
Perfluoroalkyl substances (PFASs) are used to make food packaging such as bread wrappers, microwave popcorn packs, and paper boards oil or water resistant.
However, the chemicals can permeate into the food, or from clothes onto the body, and are then ingested and absorbed into the blood stream.
Now, a study led by Harvard’s School of Public Health which followed 621 participants for two years has found a clear link between high blood levels of PFASs and lower resting metabolic rate – making it harder to stay slim after weight loss.
Lead researcher Qi Sun warns every single person in the US likely has a detectable level of PFASs in their blood.
They come from an array of products from non-stick cookware to carpet that’s been pre-treated to be stain proof to outdoor waterproof clothing.
‘It can be very useful because it repels both water and oil,’ Sun, an assistant professor in the Department of Nutrition at Harvard Chan School, told Daily Mail Online.
Another newly-discovered source of PFASs is drinking water near industrial sites.
‘This study is the first that has looked directly at how PFASs affect body regulation in humans,’ Sun said. ‘It found a clear link before exposure to the chemicals and slower metabolism.’
People with slower metabolisms, or a lower metabolic rate, burn fewer calories during normal daily activities and may have to eat less to avoid becoming overweight.
There is a lot of research available on how chemicals are linked with excess weight gain and obesity in animals, but very little data for humans.
‘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,’ Sun said.
The researchers, along with colleagues from Louisiana State University and Tulane University, analysed data from 621 overweight and obese participants in the Prevention of Obesity Using Novel Dietary Strategies clinical trial.
The trial tested the effects of four heart-healthy diets on weight loss over a period of two years.
Researchers looked at the possible connection between the amount of PFASs in participants’ blood as they entered the study and their weight loss or gain over time.
During the first six months of the trial, participants lost an average of 14lbs, but regained six pounds over the course of the following 18 months.
Those who gained the most weight back also had the highest blood concentrations of PFASs, and the link was strongest among women.
On average, women who had the highest PFAS blood levels regained about four to five pounds more body weight than women in the lowest third.
PFASs have been linked to cancer, hormone disruption, immune dysfunction, high cholesterol, and obesity.
‘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, adjunct professor of environmental health at Harvard.
‘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.’
Sun suggested that the best way for people to avoid the negative effects of PFASs is to avoid products that use them.
He said while there is not a large amount of research on the health effects of PFASs exposure, people have cause for concern.
‘We are still accumulating research to illustrate the health effects,’ he said. ‘Based on what we know so far I think people should be concerned about their exposure to PFASs.’
Source: Daily Mail