Are Forever Chemicals Really Killing Us?

Are Forever Chemicals Really Killing Us?

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The World is Paranoid About PFAS

PFAS are dangerous! Oh, and the sky is falling! Has the media overreacted to these chemicals? Here’s what you need to know.

PFAS (per- and poly-fluoroalkyl substances) are a group of chemicals often called “forever chemicals” because they stubbornly refuse to break down. They’ve lately garnered a lot of attention from various media outlets because they’re seemingly the cause of just about all society’s problems. Heck, even T Nation sounded an alarm about them.
There’s certainly some evidence to suggest that these chemicals can cause harm at high enough concentrations. But there’s also a great deal of observational data showing correlations with all sorts of endpoints that, rather than showing true evidence of harmful effects, may simply reflect that PFAS levels are a good marker for general health (more on that later).
This is inherently the problem with observational research. First, despite all the recent attention, PFAS aren’t a new group of chemicals (1). They’ve been around since the 1940s, and humans have been exposed to these compounds for about 70 years.
They’re present in various products that most people use in their homes: paper and cardboard packaging, Teflon coating, Scotchgard, cosmetics, and the list goes on. The two most widely known are perfluorooctanoic acid (PFOA) and perfluorooctane sulfonic acid (PFOS).
They’re also commonly used in building materials. Given their widespread use and their persistence in the environment (in the air, dust, water, and soil), they’ll continue to be found in our bodies for a long time to come (1).
However, blood levels of PFOA and PFOS have been greatly declining in the U.S. population since manufacturers have begun phasing them out of products.

Cardiovascular Disease and Death: PFAS or Terrible Lifestyle?
While epidemiological studies show an association between these chemicals and cardiovascular disease and all-cause mortality, there are also associations between disease/death and terrible lifestyle choices. That may be confounding the association between PFAS and kicking the bucket.
For example, fast food, pizza, microwave popcorn, ice cream, soda, fried (not omega-3 rich) fish, candy, salad dressing, butter, cheese, and white rice have positive associations with PFAS levels (1-5). However, eating at home shows an inverse association with PFAS levels, while going out for fast food is associated with a higher level (2).
Those eating a diet in omega-3-rich fish, fiber, fruit, and vegetables also show lower PFAS levels (4), while consuming a diet rich in fried fish, low-fiber foods, and high-fat bread/cereal/rice/pasta was associated with higher PFAS plasma concentrations (4).
This begs the question: Are at least some of these proposed adverse effects of PFAS simply confounded by the fact that lifestyle choices known to improve health are associated with lower PFAS exposure, while unhealthy choices are associated with higher PFAS exposure?
It’s not surprising given that PFAS are found in fast food containers and packaging, non-stick paper, pizza boxes, and plastic used for various foods (butter, microwave popcorn, ice cream, candy) (6).
Researchers with Tunnel Vision?
One group of researchers speculated that spending more time indoors could lead to adverse health effects. The adverse effects presumably weren’t due to the lack of any physical activity and being sedentary but due to the exposure to PFAS from the carpet and couch (5).
That seems like a stretch. I can’t help but think we’ve become too accustomed to blaming various chemicals for many of our preventable disease states when diet and physical activity (or lack thereof) are really to blame.

Chemically Induced Obesity?
One telling study followed overweight and obese adults assigned to either a placebo group (they received only information on diet and exercise) or an interventional group (they received training in diet, physical activity, and behavior modification with goals of achieving 7% weight loss and maintenance of 150 minutes of weekly physical activity) over 15 years (7).
The results weren’t particularly surprising. Those in the interventional group failed to have any association between PFAS and weight gain. In other words, even with elevated PFAS levels, there was no association with weight gain.
However, those in the placebo group did show an association between PFAS and weight gain. The authors concluded that PFAS might act as obesogens – compounds capable of inducing or increasing the likelihood of getting fat – but changes in diet and exercise can attenuate their effects. I guess that’s one interpretation. Another interpretation, perhaps more plausible, is that obesity, in this case, isn’t chemically induced but is modifiable with diet and exercise.
Exercise and eating fruits and vegetables are powerful modifiers that decrease the risk of all-cause mortality and cardiovascular disease (8-14), yet it seems that PFAS often end up taking the blame. These seemingly myopic researchers aren’t bothering to consider these factors, not to mention the role a sedentary lifestyle and poor diet can play in getting sick and dying.
No, it seems that PFAS may be more of a bystander, guilty through association rather than an actual cause of obesity and various diseases.
While it’s true that most studies evaluating the association between PFAS and various diseases adjust for BMI, physical activity, and diet, this doesn’t rule out residual confounding or unmeasured confounding. We must also consider the reliability of whichever source is being relied upon for these estimates – self-reported data for exercise and diet may be inaccurate. This may bias results and cause inadequate adjustment for confounding (15).

Low Levels of PFAS Might Just Mean You’re Exercising and Eating Right
By all means, avoid PFAS-containing items as much as you can. It certainly can’t hurt, but don’t let the constant media attention scare you.
Continue living a healthy lifestyle and maybe consider a top-of-the-line water filtration system, but try not to sweat the rest. Many of the associations between PFAS levels and many diseases probably aren’t due to PFAS itself but confounders, including physical activity and diet.
This makes the presence of high levels of PFAS a good indicator of poor health, but perhaps not the cause of it. Conversely, the lack of high levels might indicate the good health that results from exercise and a good diet that’s coincidentally related to a low intake of PFAS.
Individuals with extreme occupational exposure to PFAS or near sites of known contamination warrant the most concern. But it’s not worth losing sleep over for the rest of us.


Gaines LGT. Historical and current usage of per- and polyfluoroalkyl substances (PFAS): A literature review. Am J Ind Med. 2022 May 25. doi: 10.1002/ajim.23362. Epub ahead of print. PMID: 35614869.

Susmann HP, Schaider LA, Rodgers KM, Rudel RA. Dietary Habits Related to Food Packaging and Population Exposure to PFASs. Environ Health Perspect. 2019 Oct;127(10):107003. doi: 10.1289/EHP4092. Epub 2019 Oct 9. PMID: 31596611; PMCID: PMC6867167.

Park SK, Peng Q, Ding N, Mukherjee B, Harlow SD. Determinants of per- and polyfluoroalkyl substances (PFAS) in midlife women: Evidence of racial/ethnic and geographic differences in PFAS exposure. Environ Res. 2019 Aug;175:186-199. doi: 10.1016/j.envres.2019.05.028. Epub 2019 May 18. PMID: 31129528; PMCID: PMC6579633.

Lin PD, Cardenas A, Hauser R, Gold DR, Kleinman KP, Hivert MF, Fleisch AF, Calafat AM, Sanchez-Guerra M, Osorio-Yáñez C, Webster TF, Horton ES, Oken E. Dietary characteristics associated with plasma concentrations of per- and polyfluoroalkyl substances among adults with pre-diabetes: Cross-sectional results from the Diabetes Prevention Program Trial. Environ Int. 2020 Apr;137:105217. doi: 10.1016/j.envint.2019.105217. Epub 2020 Feb 18. PMID: 32086073; PMCID: PMC7517661.

Seshasayee SM, Rifas-Shiman SL, Chavarro JE, Carwile JL, Lin PD, Calafat AM, Sagiv SK, Oken E, Fleisch AF. Dietary patterns and PFAS plasma concentrations in childhood: Project Viva, USA. Environ Int. 2021 Jun;151:106415. doi: 10.1016/j.envint.2021.106415. Epub 2021 Mar 8. PMID: 33706127; PMCID: PMC7979513.

Ramírez Carnero A, Lestido-Cardama A, Vazquez Loureiro P, Barbosa-Pereira L, Rodríguez Bernaldo de Quirós A, Sendón R. Presence of Perfluoroalkyl and Polyfluoroalkyl Substances (PFAS) in Food Contact Materials (FCM) and Its Migration to Food. Foods. 2021 Jun 22;10(7):1443. doi: 10.3390/foods10071443. PMID: 34206351; PMCID: PMC8306913.

Cardenas A, Hauser R, Gold DR, Kleinman KP, Hivert MF, Fleisch AF, Lin PD, Calafat AM, Webster TF, Horton ES, Oken E. Association of Perfluoroalkyl and Polyfluoroalkyl Substances With Adiposity. JAMA Netw Open. 2018 Aug 3;1(4):e181493. doi: 10.1001/jamanetworkopen.2018.1493. PMID: 30646133; PMCID: PMC6324277.

Beyer KMM, Szabo A, Hoormann K, Stolley M. Time spent outdoors, activity levels, and chronic disease among American adults. J Behav Med. 2018 Aug;41(4):494-503. doi: 10.1007/s10865-018-9911-1. Epub 2018 Jan 30. PMID: 29383535; PMCID: PMC6031452.

Loef M, Walach H. The combined effects of healthy lifestyle behaviors on all cause mortality: a systematic review and meta-analysis. Prev Med. 2012 Sep;55(3):163-70. doi: 10.1016/j.ypmed.2012.06.017. Epub 2012 Jun 24. PMID: 22735042.

Wang X, Ouyang Y, Liu J, Zhu M, Zhao G, Bao W, Hu FB. Fruit and vegetable consumption and mortality from all causes, cardiovascular disease, and cancer: systematic review and dose-response meta-analysis of prospective cohort studies. BMJ. 2014 Jul 29;349:g4490. doi: 10.1136/bmj.g4490. Erratum in: BMJ. 2014;349:5472. PMID: 25073782; PMCID: PMC4115152.

Samitz G, Egger M, Zwahlen M. Domains of physical activity and all-cause mortality: systematic review and dose-response meta-analysis of cohort studies. Int J Epidemiol. 2011 Oct;40(5):1382-400. doi: 10.1093/ije/dyr112. Epub 2011 Sep 5. PMID: 22039197.

Warburton DE, Nicol CW, Bredin SS. Health benefits of physical activity: the evidence. CMAJ. 2006 Mar 14;174(6):801-9. doi: 10.1503/cmaj.051351. PMID: 16534088; PMCID: PMC1402378.

Autenrieth CS, Baumert J, Baumeister SE, Fischer B, Peters A, Döring A, Thorand B. Association between domains of physical activity and all-cause, cardiovascular and cancer mortality. Eur J Epidemiol. 2011 Feb;26(2):91-9. doi: 10.1007/s10654-010-9517-6. Epub 2010 Dec 14. PMID: 21153912.

Bellavia A, Larsson SC, Bottai M, Wolk A, Orsini N. Fruit and vegetable consumption and all-cause mortality: a dose-response analysis. Am J Clin Nutr. 2013 Aug;98(2):454-9. doi: 10.3945/ajcn.112.056119. Epub 2013 Jun 26. PMID: 23803880.

Phillips AN, Smith GD. Bias in relative odds estimation owing to imprecise measurement of correlated exposures. Stat Med. 1992 May;11(7):953-61. doi: 10.1002/sim.4780110712. PMID: 1604073.

Great article Cy, I’ve been visiting T-Nation since ’98 and I always look forward to your level headed approach.
How concerned are you with eating freshwater fish? I have a lake place here in MN, (far from the Great Lakes), and I’m conflicted if I should pay attention to current thought processes of “once per year” or whatever. We typically eat fish from the lake once per week in the summer.
Thoughts? Look forward to more of your stuff as always

Good article, often thought of these issues. Although if there is a chance that these chemicals are causing problems in our bodies is not beneficial to use alternative ways to manufacture our products. Considering the amounts of carcinogens we come in contact with on a daily basis. Our work and then of course our homes chemicals and such we clean with, chemicals our food is sprayed with. I try to cut out a lot of those things in my life reduce the amount I take in. I think big manufactures should take best interest in cleaning up our food chain with health interests in mind not profit above all else. I am willing to pay more for better food and products and I consider myself of below average income. My body is more important than money you cant spend it if your not here.

I would think that freshwater fish in your area is probably safer than the vegies you purchase in your store. I know there are some issues they say with the great lakes though. I would suggest you get your fish more from a river that the fish return from the ocean like salmon if you can find that in your area. I live next to a big river that salmon migrate through most of the year and have eaten a lot of salmon, Tuna from the coast I live about 80 miles from for all of my life so…

Sadly the only ocean access to MN is through the great lakes, which is by far worst according to the studies. So I’m hoping my little inland lake is the least affected. Common sense tells me that it is, and while I don’t eat many vegetables, I agree on that point.
Some studies my DNR did showed that even inner lakes like mine are concerning when it comes to the LEVELS of PFAS, but hoping Cy can shine some common sense on it.

Everything is killing us

MN health department has guidelines for species and body of water about safe consumption limits. Only a few limits concern PFOS, most are about mercury.
Other states should have similar webpages.

I only eat trout 2-3 times a year but when I do I go to the high mountain lakes in my area 5-8 mile hike stay for few days stock up and go home. I assume these are cleaner lakes since no industry and very little influence by man. I honestly would not eat any other trout these are amazing fish all wild very delicious.

Inland trout is my favorite fish by far. I like to pretzel crust them and dip in a hollandaise.

yeah, it may have been this page, but there is definitely much more to MN PFAs study. I spend a night looking around:

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