We already know that what’s in junk food is pretty bad for us, but what’s around it could be harmful too. Findings in a new study, published in the journal PLOS Medicine, has reiterated the impact that perfluoroalkyl substances (PFASs) have on our health.
PFASs are chemicals with commercial and industrial uses, found in everything from food packaging to textiles. They can be ingested or inhaled and absorbed into the bloodstream, but are not able to be metabolised 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. High levels of PFAS exposure has previously been linked to cancer, hormone disruption, immune dysfunction, high cholesterol, and obesity, but some still dispute their influence.
In a recent experiment, the researchers from Harvard’s School of Public Health followed 621 overweight and obese participants for two years of a diet-induced weight loss trial. On average, those in the program lost 6.4 kilograms in the first six months, but regained 2.7 kg over the following year and a half.
They found that primarily female participants with higher baseline levels of PFASs in their blood had lower resting metabolic rates and were more likely to regain weight they had lost over the period. Women who had the highest PFAS blood levels regained, on average, 1.7-2.2 kg more body weight than women with lower levels.
“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.”
According to Queensland Government guidelines, the manufacture and use of some PFAS are being discontinued or limited through international agreements and voluntary actions by manufacturers. However, they may still be present in the environment thanks to historic use or release from pre-treated articles imported into Australia.
But this isn't cause for alarm. Data from the most recent Australian Total Diet Survey, our country's most comprehensive assessment of consumers’ dietary exposure to pesticide residues, contaminants and other substances in food, showed that our exposure to food packaging chemicals is low.
Still food for thought.