[ad_1]
The world is paranoid about PFAS
PFAS are dangerous! Oh, the sky is falling! Has the media overreacted to these chemicals? Here’s what you need to know.
PFAS (Per- and Poly-Fluorinated Alkyl Substances) are a group of chemicals often referred to as “permanent chemicals” because of their stubborn refusal to break down. They’ve gotten a lot of attention in various media lately because they seem to be at the root of almost all social problems.Heck, even T Nation sounds Call the police on them.
There is certainly some evidence that these chemicals can cause harm in high enough concentrations. But there is also a wealth of observational data showing correlations with various endpoints, rather than showing real evidence of harmful effects, and may simply reflect that PFAS levels are good markers of general health (more on that later).
This is essentially a question of observational research. First, despite recent attention, PFAS are not a new group of chemicals (1). They have been around since the 1940s, and humans have been exposed to these compounds for about 70 years.
They are found in a variety of products that most people use at home: paper and cardboard packaging, Teflon coatings, scotch whiskey, cosmetics, and more. The two most well known are perfluorooctanoic acid (PFOA) and perfluorooctanesulfonic acid (PFOS).
They are also commonly used in building materials. Given their widespread use and their persistence in the environment (in air, dust, water, and soil), they will continue to exist in our bodies for a long time to come (1).
However, since manufacturers began phasing out PFOA and PFOS products, blood levels of PFOA and PFOS in the US population have dropped dramatically.
Cardiovascular Disease and Death: PFAS or Bad Lifestyle?
While epidemiological studies have shown an association between these chemicals and cardiovascular disease and all-cause mortality, there is also an association between illness/death and dreaded disease Lifestyle choices. This can confuse the association between PFAS and kicking the bucket.
For example, fast food, pizza, microwave popcorn, ice cream, soda, fried (not rich in omega-3) fish, candy, salad dressing, butter, cheese, and white rice were positively associated with PFAS levels (1-5). However, eating at home was negatively associated with PFAS levels, while eating out for fast food was associated with higher levels (2).
Those who ate a diet rich in omega-3 fish, fiber, fruits, and vegetables also showed lower PFAS levels (4), along with eating a diet rich in fried fish, low fiber foods, and high-fat bread/grain/rice / Pasta was associated with higher PFAS plasma concentrations (4).
This begs the question whether at least some of these proposed PFAS side effects are simply confounded by the fact that improved healthy lifestyle choices are known to be associated with lower PFAS exposure, while unhealthy choices are associated with higher PFAS Exposure related?
It should come as no surprise that PFAS are found in fast food containers and packaging, non-stick paper, pizza boxes, and plastics used in a variety of foods (butter, microwave popcorn, ice cream, candy) (6).
Researchers with tunnel vision?
Spending more time indoors may have adverse health effects, a team of researchers speculates. Presumably, the adverse effects are not due to lack of any physical activity and sedentary behavior, but rather due to exposure to PFAS from carpets and couches (5).
This seems a bit far-fetched. I can’t help but think that we’ve become conditioned to attribute many preventable disease states to various chemicals when diet and physical activity (or lack thereof) really are to blame.
Chemical obesity?
A convincing study assigned overweight and obese adults to a placebo group (they received information about diet and exercise only) or an intervention group (they received training on diet, physical activity and behavioral modification, with the goal of Achieving 7% weight loss and maintaining 150 minutes of physical activity per week) over 15 years (7).
The results weren’t particularly surprising. Participants in the intervention group failed to find any association between PFAS and weight gain. In other words, even elevated PFAS levels were not associated with weight gain.
However, the placebo group did show an association between PFAS and weight gain. The authors concluded that PFAS may act as obesogens — compounds that induce or increase the likelihood of obesity — but that changes in diet and exercise can attenuate their effects. I guess that’s an explanation. An alternative explanation, and perhaps more plausible, is that obesity in this case is not chemically induced but modifiable through diet and exercise.
Exercising and eating fruits and vegetables are powerful modulators of reduced risk of all-cause mortality and cardiovascular disease (8-14), but it appears that PFAS often end up being the culprit. These seemingly short-sighted researchers didn’t bother to consider these factors, let alone the role that a sedentary lifestyle and poor diet played in sickness and death.
No, it seems like PFAS might be more of a bystander, guilt-ridden by association than an actual cause of obesity and various diseases.
Didn’t epidemiological studies take diet and exercise into account?
While most studies evaluating associations between PFAS and various diseases do adjust for BMI, physical activity, and diet, this does not rule out residual or unmeasured confounding. We must also consider the reliability of any sources on which these estimates are relied upon—self-reported exercise and diet data may not be accurate. This may bias the results and lead to insufficient adjustment for confounding (15).
Low levels of PFAS may just mean you’re exercising and eating right
In any case, avoid PFAS-containing items as much as possible. It certainly can’t hurt, but don’t let the constant media attention scare you.
Go ahead and maintain a healthy lifestyle, maybe consider a top-of-the-line water filtration system, but try not to waste the rest of your time. Many of the associations between PFAS levels and many diseases may not be due to PFAS per se but to confounding factors, including physical activity and diet.
This makes high levels of PFAS a good indicator of poor health, but probably not the cause of it. Conversely, the lack of high levels may indicate that the health benefits of exercise and a good diet are precisely related to low PFAS intake.
Individuals with extreme occupational exposure to PFAS or near known contaminated sites are of greatest concern. But for the rest of us, the insomnia isn’t worth it.
refer to
refer to
-
Gaines LGT. Historical and current uses of perfluorinated and polyfluoroalkyl substances (PFAS): A literature review. Am J Ind Med. May 25, 2022. doi: 10.1002/ajim.23362. Epub preceded printing. PMID: 35614869.
-
Susmann HP, Schaider LA, Rodgers KM, Rudel RA. Dietary habits associated with food packaging and population exposure to PFAS. Environmental health perspective. 2019 Oct;127(10):107003. Department of the Interior: 10.1289/EHP4092. Epub October 9, 2019. PMID: 31596611; PMCID: PMC6867167.
-
Park SK, Peng Q, Ding N, Mukherjee B, Harlow SD. Determinants of perfluoroalkyl and polyfluoroalkyl substances (PFAS) in middle-aged women: Evidence for racial/ethnic and geographic differences in PFAS exposure. Environmental Res 2019 Aug;175:186-199. doi: 10.1016/j.envres.2019.05.028. Electronic version 18 May 2019. 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 in prediabetic adults: Cross-sectional results from the Diabetes Prevention Program Trial. environmental interpretation. 2020 Apr;137:105217. doi: 10.1016/j.envint.2019.105217. Electronic version February 18, 2020. 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: The Viva America Project. Environ Int 2021 Jun;151:106415. doi: 10.1016/j.envint.2021.106415. Available electronically March 8, 2021. PMID: 33706127; PMCID: PMC7979513.
-
RamÃrez Carnero A, Lestido-Cardama A, Vazquez Loureiro P, Barbosa-Pereira L, RodrÃguez Bernaldo de Quirós A, Sendón R. Presence and implications of perfluoroalkyl and polyfluoroalkyl substances (PFAS) in food contact materials (FCMs) its migration into food. food. 2021 Jun 22;10(7):1443. Home Office: 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 obesity. JAMA Network 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. Outdoor time, activity levels, and chronic disease among US adults. J Behavioral Med. 2018 Aug;41(4):494-503. Department of the Interior: 10.1007/s10865-018-9911-1. Available electronically 30 January 2018. PMID: 29383535; PMCID: PMC6031452.
-
Loef M, Walach H. Combined effects of healthy lifestyle behaviors on all-cause mortality: a systematic review and meta-analysis. Previous 2012 Sep;55(3):163-70. doi: 10.1016/j.ypmed.2012.06.017. Epub June 24, 2012. PMID: 22735042.
-
Wang X, Ouyang Y, Liu J, Zhu M, Zhao G, Bao W, Hu FB. Fruit and vegetable consumption and all-cause, cardiovascular disease, and cancer mortality: a systematic review and dose-response meta-analysis of prospective cohort studies. British Medical Journal. 2014 Jul 29;349:g4490. Department of the Interior: 10.1136/bmj.g4490. Errata: BMJ. 2014;349:5472. PMID: 25073782; PMCID: PMC4115152.
-
Samitz G, Egger M, Zwahlen M. Physical activity domains and all-cause mortality: a systematic review and dose-response meta-analysis of cohort studies. International Journal of Epidemiology. 2011 Oct;40(5):1382-400. Home Office: 10.1093/ije/dyr112. Epub 5 September 2011. PMID: 22039197.
-
Warburton DE, Nicole CW, Bredding SS. The health benefits of physical activity: the evidence. CMAJ. 2006 Mar 14;174(6):801-9. Department of the Interior: 10.1503/cmaj.051351. PMID: 16534088; PMCID: PMC1402378.
-
Autenrieth CS, Baumert J, Baumeister SE, Fischer B, Peters A, Döring A, Thorand B. Association between areas of physical activity and all-cause, cardiovascular, and cancer mortality. Eur J Epidemiol. 2011 Feb;26(2):91-9. Department of the Interior: 10.1007/s10654-010-9517-6. Epub Dec 14, 2010. PMID: 21153912.
-
Bellavia A, Larsson SC, Bottai M, Wolk A, Orsini N. Fruit and vegetable consumption and all-cause mortality: a dose-response analysis. I’m J Clin Nutr. 2013 Aug;98(2):454-9. Home Office: 10.3945/ajcn.112.056119. Epub June 26, 2013. PMID: 23803880.
-
Phillips AN, Smith GD. Estimates of relative odds are biased by imprecise measurements of relevant exposures. Statistical Medicine. 1992 May;11(7):953-61. Home Office: 10.1002/sim.4780110712. PMID: 1604073.
[ad_2]
