Would you like some chemicals with that?

If anyone needs another good reason for choosing home-cooked food over restaurants or take-out, here it is: a study has found it lowers exposure to fluorinated chemicals commonly lurking in food packaging.

PFAS (per- and polyfluoroalkyl substances), also known as PFCs, are a ubiquitous group of synthetic compounds that are also extensively used in non-stick, stain-resistant and waterproof products, such as cookware, carpeting and outdoor gear.

PFAS exposure has been linked to an assortment of health problems including liver damage, thyroid disease, lowered fertility, weight gain, hormone suppression, low birth weight, developmental toxicity and cancer. 

Also concerning, they are highly resistant to degradation, lingering and accumulating in the environment and in the body.

To test people’s dietary exposure, Herbert Susmann and colleagues from the Silent Spring Institute in Massachusetts, US, analysed a decade of data from the National Health and Nutrition Examination Survey (NHANES).

More than 10,000 participants had provided detailed dietary information and blood samples that had been analysed for five different PFAS chemicals.

The researchers found that eating more meals cooked at home was associated with consistently lower levels – ranging from 32% to 50% – of all chemicals tested than eating food from other sources, including fast food, pizza and other restaurants.

Eating out either had no or positive associations with PFAS levels. Strikingly, eating microwave popcorn had the strongest associations – and people who ate it daily had higher PFAS levels with up to a 63% increase in perfluorodecanoic acid (PFDA).

Co-author Laurel Schaider notes that this study is the first to show a link between different food sources and PFAS exposures in the US population.

“Our results suggest migration of PFAS chemicals from food packaging into food can be an important source of exposure to these chemicals,” she adds.

The researchers didn’t analyse PFAS levels in the food or food packaging directly, but previous studies have identified their presence, including an earlier one by the group.

It’s notable that the data were only collected up to 2014 and didn’t include new PFAS that manufacturers have been using to replace the long-chain PFAS. 

But the researchers raise concerns about these short-chain replacements, as preliminary research suggests they migrate more readily from food packaging and could have similar adverse health outcomes.

They are therefore calling for restrictions on the whole class of chemicals.

“Concerns about persistence, mobility, and potential toxicity support a precautionary approach to protecting public and environmental health by avoiding the use of fluorinated chemicals in [food contact materials] entirely,” they write.

Co-author Kathryn Rodgers notes that food packaging also contains other worrying chemicals such as BPA, a hormone disruptor, and phthalates.

“The general conclusion here is the less contact your food has with food packaging, the lower your exposure to PFAS and other harmful chemicals,” she says. 

“These latest findings will hopefully help consumers avoid these exposures and spur manufacturers to develop safer food packaging materials.”