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Teabags and Processed Meats May Be Key Dietary Sources of PFAS

Teabag in a glass.
Credit: TeaCora Rooibos/Unsplash
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Want to keep your “forever chemical” exposure to a minimum? Perhaps start making more of your own meals and cutting out cups of tea.

That’s one interpretation of a new study of young adult diets published in Environmental International.

After comparing the eating habits of 727 young US adults with their blood levels of per- and polyfluoroalkyl substances (PFAS), the researchers found that the participants who ate more takeouts and processed meats were more likely to have higher levels of PFAS.

Young people who drank more tea were also more likely to have high PFAS levels than those who drank more sugary drinks.

The PFAS diet

PFAS are a group of compounds used to waterproof consumer products like pans, packaging and paints. They’re known as “forever chemicals” because they don’t degrade naturally.


This robustness is all the more troubling considering the recent wave of research linking the chemicals to some cancer types and low birth weight.

To better understand how these compounds get into our bodies, researchers from the University of Southern California surveyed 727 young adults who were part of two ongoing study cohorts; one group (604 young adults) had an average age of 19 and only had their blood tested once. The other group (123 young adults) had their blood tested twice, first when they were 20 and again when they were 24.

After twice quizzing the young people on what they’d consumed in the past 24 hours, the researchers analyzed the participants’ blood for traces of different PFAS chemicals.

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The team found that the participants who drank plenty of tea and ate a large amount of pork, hot dogs and other processed meats had significantly higher PFAS levels in their blood.

Within the smaller participant group, between their first and second blood tests, an additional serving of tea was linked to 24.8% higher levels of perfluoro-hexanesulphonic acid (PFHxS), 16.17% higher levels of perfluoroheptanesulfonic acid (PFHpS) and 12.6% higher perfluorononanoic acid (PFNA).

While the researchers can’t be sure why tea was so associated with PFAS contamination, they posit that the paper teabags may be to blame. As for the processed meat connection, the contamination could also begin in the packaging or much earlier, they say.

“PFAS can accumulate in meat products through a variety of exposure pathways,” Hailey Hampson, a doctoral student in the Keck School of Medicine’s Division of Environmental Health and the study’s lead author, told Technology Networks.

“Meat may come from animals that were raised in PFAS-contaminated areas. Additionally, meat products may be packaged and stored in grease-resistant packaging that contains PFAS. And processed meats may further accumulate PFAS through contact during processing or cooking.”


Home cooking does, however, appear to be a good way of minimizing PFAS contamination; the participants who prepared more meals at home tended to have lower levels of the forever chemicals. This was likely because they were avoiding the packaging and grease-proof paper that comes with takeout food, say the researchers.

Eating fish wasn’t significantly associated with higher PFAS levels, despite the animals being known hyper-accumulators of the forever chemicals. This surprising finding can be explained, said Hampson, by the lack of seafood in the participants’ diets.

“We did not see strong associations with seafood and PFAS levels in our study, primarily because consumption of seafood and fish was very low in the primary study population,” she said.

“In general, the consumption of seafood and fish for individuals under the age of 19 is 6% nationally, and 20% for young adults over the age of 20. Therefore, while seafood and fish consumption are major contributors to PFAS exposures in adult populations and populations consuming greater amounts of these foods, our study found that other foods were greater contributions for these young adult populations.”

Hampson and her team are now conducting research on the extent of PFAS contamination in popular tea brands, as well as a follow-up study on diet and PFAS levels in a multi-ethnic group of participants.

Reference: Hampson HE, Costello E, Walker DI, Wang H, et al. Associations of dietary intake and longitudinal measures of per- and polyfluoroalkyl substances (PFAS) in predominantly Hispanic young Adults: A multicohort study. Enviro Inter 2024. doi: 10.1016/j.envint.2024.108454

Hailey Hampson, a doctoral student in the Keck School of Medicine’s Division of Environmental Health, was speaking to Leo Bear-McGuinness, science writer for Technology Networks.