This crap is everywhere!
Zara Abrams
PFAS are known to be harmful to health: They can disrupt hormones, weaken bones and increase disease risk. Sometimes called “forever chemicals” because they take so long to break down, PFAS are used in fabrics, furniture and other household items—but they are also hard to get rid of.
Recent tests now trace the
chemicals to livestock, drinking water and food packaging, but little is known
about the extent of that contamination.
A new study, funded in part by the National Institutes of Health and led by researchers at the Keck School of Medicine of USC, is uncovering key details about the link between PFAS and diet.
Researchers studied two multiethnic groups of young adults, one a nationally representative sample and one primarily Hispanic. They found that greater consumption of tea, processed meats and food prepared outside the home was associated with increased levels of PFAS in the body over time.
“To our knowledge, this is the first study to examine how dietary factors are associated with changes in PFAS over time,” said Jesse A. Goodrich, PhD, assistant professor of population and public health sciences at the Keck School of Medicine and the study’s senior author.
“Looking at multiple time points gives
us an idea of how changing people’s diets might actually impact PFAS levels.”
The results, just published in the journal Environment
International, also point to the importance of testing and
monitoring various food and beverage products for contamination with PFAS.
“We’re starting to see that even foods that are
metabolically quite healthy can be contaminated with PFAS,” said Hailey
Hampson, a doctoral student in the Keck School of Medicine’s Division of
Environmental Health and the study’s lead author. “These findings highlight the
need to look at what constitutes ‘healthy’ food in a different way.”
Tracking change over time
The researchers studied two groups of participants: 123
young adults from the Southern California Children’s Health Study (CHS), who
were primarily Hispanic, and 604 young adults from the National Health and
Nutrition Examination Study (NHANES), a nationally representative sample.
Each participant answered a series of questions about their diet, including how frequently they consumed various foods (such as processed meats, dark green vegetables and bread) and beverages (including sports drinks, tea and milk).
They also reported how often they ate food
prepared at home, at a fast-food restaurant or at a non-fast-food restaurant,
which researchers used to infer contact with food packaging, which often
contains PFAS.
Participants also gave blood samples, which were tested
for levels of various PFAS. The CHS group was tested twice, once around age 20
and once around age 24; the NHANES group was tested once, around age 19.
In the CHS group, participants who reported higher tea consumption during the first visit had higher levels of PFAS at the follow-up visit (one additional serving of tea was linked to 24.8% higher perfluoro- hexanesulphonic acid (PFHxS), 16.17% higher perfluoroheptanesulfonic acid (PFHpS) and 12.6 % higher perfluorononanoic acid (PFNA)).
Those who reported
more pork intake on their initial visit also had higher levels of PFAS at
follow-up (one additional serving of pork was associated with 13.4 % higher perfluorooctanoic
acid (PFOA)).
Eating food prepared at home had the opposite effect: for
every 200-gram increase in home-prepared food, perfluorooctanesulfonic acid
(PFOS) levels were .9% lower at baseline and 1.6 % lower at follow-up. These
findings are important because they not only reveal the presence of traditional
PFAS, such as PFOA and PFOS, but also more recently developed PFAS, including
PFHxS and PFHpS.
Those results were confirmed in the NHANES group.
Participants who consumed more tea, hot dogs and processed meats had higher
PFAS levels; eating more home-prepared food was linked to lower PFAS levels.
“This really helped us determine that the associations we
are seeing aren’t just true for one geographical location, but are actually
applicable to people across the country,” Goodrich said.
A step in the right direction
Observing that links between PFAS levels and food
products change over time suggests that dietary changes could impact PFAS
levels in the body, Hampson said. The findings also suggest that public
monitoring of certain products, such as beverages, could help identify and
eliminate sources of contamination.
But food packaging is more ubiquitous and may require a
bolder approach. In 2023, California’s Attorney General issued an advisory letter requiring
manufacturers of food packaging and paper straws to disclose PFAS levels in
their products.
“That’s a really good step in the right direction, and
our findings highlight the need for more of those types of regulations across
the country,” Goodrich said.
Goodrich, Hampson and their 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.
About this research
In addition to Goodrich and Hampson, the study’s other
authors are Elizabeth Costello, Hongxu Wang, Brittney Baumert, Sarah Rock,
Frank Gilliland, David Conti, Zhanghua Chen and Lida Chatzi from the Department
of Population and Public Health Sciences, Keck School of Medicine, University
of Southern California; Michael Goran from the Department of Pediatrics, Keck
School of Medicine, University of Southern California and the Saban Research
Institute, Children’s Hospital Los Angeles; Douglas Walker and Damaskini Valvi
from the Department of Environmental Medicine and Public Health, Icahn School
of Medicine at Mount Sinai; Dean P. Jones from the Division of Pulmonology,
Allergy, Critical Care and Sleep Medicine, Emory University; and Tanya Alderete
from the Department of Integrative Physiology, University of Colorado Boulder.
This work is supported by the National Institute of Environmental Health Sciences [R01ES029944]; the Southern California Children’s Environmental Health Center grants, funded by NIEHS [P01ES022845, 5P30ES007048, P01ES011627]; the Environmental Protection Agency [RD83544101]; the Hastings Foundation; and additional funding from the National Institutes of Health [R25GM143298, P30ES007048, R01ES030691, R01ES030364, R21ES029681, R21ES028903, P30ES007048, R00ES027870, R01ES033688, P30ES023515, U2CES030859, R01ES032831, P01- CA196569, P30ES007048, R01ES030691, R01ES030364, R21ES029681, R21ES028903, R00ES027853, P50MD017344, P50MD017344, 2CES030163, P30ES019776, R24ES029490, R01ES032189, R21ES031824, T32ES013678, T32ES013678, T32ES013678].