PFAS, the Forever Chemicals: Human Health Impact & Interventions
Written by: Functional Medicine Institute Staff
Termed “forever chemicals,” PFAS are a class of over 4,700 heterogenous manmade compounds that persist in the environment. Increasing evidence suggests that these ubiquitous compounds are detrimental to human health because they resist environmental degradation and have a significant potential to bioaccumulate, contaminating food chains.
Since the Industrial Revolution, increasing levels of chemical pollution have been altering the Earth’s system-processes, degrading the vitality of human health.1 Some scientists warn that chemical pollution is one of the primary environmental boundaries that should not be crossed to protect the human population.1,2 In August 2022, the US Environmental Protection Agency (EPA) issued a new advisory warning that two of the most widely used per-and polyfluoroalkyl substances (PFAS) found in drinking water pose health risks and labeled them as hazardous.3 Human biomonitoring studies report widespread exposure to PFAS, with detection rates of over 97% in the blood of US adults.4
Termed “forever chemicals,” PFAS are a class of over 4,700 heterogenous manmade compounds that persist in the environment.5Humans have exploited PFAS for close to 60 years due to their chemical stability and resistance to thermal degradation, as well as their wide applicability in the industrial sector and in consumer products.5Increasing evidence suggests that these ubiquitous compounds are detrimental to human health because they resist environmental degradation and have a significant potential to bioaccumulate, contaminating food chains.5 Some PFAS have been detected in the blood, milk, urine, tissues, and organs of people5 and have been associated with a number of adverse health effects, including liver disease and cancer, thyroid disease, diabetes, adverse reproductive outcomes, and more.4-13
What do the most recent scientific studies tell us about the toxic health effects of PFAS? How can practitioners assess for PFAS exposure and educate patients about the importance of toxicity testing and behavior change for reducing encounters?
Transmission & Human Health Effects of PFASSignificant amounts of PFAS pollution are derived from industrial and waste-water treatment plants, which release these chemicals.5 When released, these pervasive pollutants contaminate the natural world by entering the atmosphere, the water (ground water, fresh water, marine water, and drinking water), and the soil, contaminating food sources.5
PFAS are also commonly used in a wide array of applications and products such as pesticide formulation, firefighting foams, cosmetics, textiles, oil production, medical products, food processing, building and construction, cables and wiring, and electronics and semiconductors.5However, dietary intake and the consumption of drinking water represent major pathways for exposure to PFAS in the general population. Specifically, perfluorooctane sulfonate (PFOS) and perfluorooctanoic acid (PFOA) are two of the PFAS species that, among others, contribute most to human exposure.
It is important to note that the potential of PFAS to negatively impact health is multifactorial and includes considerations around conditions of exposure such as concentration, duration, and route of exposure, as well as demographic characteristics of the exposed individual, including genetic predisposition.5 That said, the human health effects of PFAS include, but are not limited to:
- Liver Disease & Cancer: A 2022 first-of-its-kind nested case-control study published in the Journal of Hepatology found that high PFOS levels (one form of PFAS) were associated with a 4.5-fold increased risk of non-viral hepatocellular carcinoma (HCC) in humans.14 Recent evidence also suggests that PFAS are associated with increased risk of metabolic dysfunction–associated steatotic liver disease (MASLD), previously called non-alcoholic fatty liver disease (NAFLD), in both children and adults.9
- Thyroid Disease & Cancer: Studies suggest that PFAS may alter thyroid hormones and potentially contribute to thyroid disease, dysfunction, and cancer.7,8
- Diabetes: While research continues to clarify the associations, studies suggest that PFAS exposure may increase the risk of incident type 2 diabetes.10,11 A 2023 systematic review and meta-analysis of 22 studies suggests that exposure to PFAS may increase type 2 diabetes risk among the general population.10 In the review, statistically significant PFAS-T2DM associations were consistent in cohort studies, while the associations were almost non-significant in case-control and cross-sectional studies.10
- Reproductive Outcomes: Pregnant women and their developing children may be vulnerable to PFAS. A 2021 systematic review and meta-analysis suggests that PFAS exposure during pregnancy may be associated with increased preterm birth risk, the risk of miscarriage, and preeclampsia.13
Sources of ExposureHumans may be exposed to PFAS in myriad ways, most commonly through drinking water, through contaminated food sources, and in household products.15,16 Understanding human exposure is important in mitigating health effects. Filtering drinking water and lifestyle modifications such as modifying the diet may be accessible steps to reducing exposure. Changes in diet may potentially reduce PFAS exposure, given that PFAS can be present in a number of food products, including wild-caught fish and game, livestock, and produce, as well as prepared foods.16 Fish and seafood have been identified as sources of PFAS, but the levels of PFAS vary by fish type and water body.16 To make other informed lifestyle choices, the Green Science Policy Institute has put together a list of product brands that are PFAS-free, including apparel, cosmetics, baby products, furniture, and more.
Functional Medicine Considerations“What we are trying to do in functional medicine is we’re trying to address what we call the total toxic load,” says IFM Educator Robert Rountree, MD. “What we are interested in is the way a person lives, what are all the exposures coming in called the exposome, and what are the healthy processes that go on in a person that keep that exposome from allowing this accumulation of what we call the total body burden.”
Functional medicine individual intake assessments are integral for helping identify and evaluate patterns of potential toxic exposures throughout the lifespan. These assessments help the clinician develop and personalize strategies to reduce exposure, enhance detoxification through appropriate avenues, and promote the body’s natural ability to heal. Personalized treatments may include lifestyle modifications and other techniques to increase toxicant elimination. Examples include:
- Therapeutic diets that emphasize increased fiber and specific nutrients.
- Promotion of glutathione production in the body.
- Use of saunas to increase elimination of certain toxicants through sweat and urine.
Many toxic chemicals are ubiquitous and difficult to avoid completely; however, helping a patient reduce contact with potential sources is an important goal. Identifying those contaminants specific to a patient’s daily life is a first step, followed by a clinical evaluation to assess the total toxic load or body burden. Interventions include ways to improve biotransformation and elimination. Training in functional medicine teaches clinicians how to develop personalized dietary treatments, as well as how to apply various nutraceuticals, botanicals, pharmaceuticals, and lifestyle interventions to increase the mobilization, biotransformation, and elimination of toxic compounds in the body.
REFERENCES
1. Persson L, Carney Almroth BM, Collins CD, et al. Outside the safe operating space of the planetary boundary for novel entities. Environ Sci Technol. 2022;56(3):1510-1521. doi:10.1021/acs.est.1c04158
2. Naidu R, Biswas B, Willett IR, et al. Chemical pollution: a growing peril and potential catastrophic risk to humanity. Environ Int. 2021;156:106616. doi:10.1016/j.envint.2021.106616
3. Environmental Protection Agency. EPA proposes designating certain PFAS chemicals as hazardous substances under Superfund to protect people’s health. Updated August 10, 2023. Accessed August 29, 2025. https://www.epa.gov/newsreleases/epa-proposes-designating-certain-pfas-chemicals-hazardous-substances-under-superfund
4. National Institute of Environmental Health Sciences. Perfluoroalkyl and polyfluoroalkyl substances (PFAS). National Institutes of Health. Updated May 6, 2025. Accessed August 29, 2025. https://www.niehs.nih.gov/health/topics/agents/pfc
5. Panieri E, Baralic K, Djukic-Cosic D, Buha Djordjevic A, Saso L. PFAS molecules: a major concern for human health and the environment. Toxics. 2022;10(2):44. doi:10.3390/toxics10020044
6. Fenton SE, Ducatman A, Boobis A, et al. Per- and polyfluoroalkyl substance toxicity and human health review: current state of knowledge and strategies for informing future research. Environ Toxicol Chem. 2021;40(3):606-630. doi:10.1002/etc.4890
7. Chung SM, Cha JH, Jung YH, Kim JH, Moon JS, Won KC. Non-linear associations between exposure to a mixture of per- and polyfluoroalkyl substances and thyroid hormone levels in Korean adults. Environ Int. 2025;201:109585. doi:10.1016/j.envint.2025.109585
8. Wild LE, DiStefano N, Forman G, et al. Socioeconomic disparities and risk of papillary thyroid cancer associated with environmental exposure to per- and polyfluoroalkyl substances (PFAS) in Florida. Int J Environ Res Public Health. 2025;22(8):1290. doi:10.3390/ijerph22081290
9. Costello E, Rock S, Stratakis N, et al. Exposure to per-and polyfluoroalkyl substances and markers of liver injury: a systematic review and meta-analysis. Environ Health Perspect. 2022;130(4):46001. doi:10.1289/EHP10092
10. Gui SY, Qiao JC, Xu KX, et al. Association between per- and polyfluoroalkyl substances exposure and risk of diabetes: a systematic review and meta-analysis. J Expo Sci Environ Epidemiol. 2023;33(1):40-55. doi:10.1038/s41370-022-00464-3
11. Park SK, Wang X, Ding N, et al. Per- and polyfluoroalkyl substances and incident diabetes in midlife women: the Study of Women’s Health Across the Nation (SWAN). Diabetologia. 2022;65(7):1157-1168. doi:10.1007/s00125-022-05695-5
12. An L, Huang Y, Wang Y, et al. Assessment of ovarian dysfunction induced by environmental toxins: a systematic review. Front Public Health. 2025;13:1575418. doi:10.3389/fpubh.2025.1575418
13. Gao X, Ni W, Zhu S, et al. Per- and polyfluoroalkyl substances exposure during pregnancy and adverse pregnancy and birth outcomes: a systematic review and meta-analysis. Environ Res. 2021;201:111632. doi:10.1016/j.envres.2021.111632
14. Goodrich JA, Walker D, Lin X, et al. Exposure to perfluoroalkyl substances and risk of hepatocellular carcinoma in a multiethnic cohort. JHEP Rep. 2022;4(10):100550. doi:10.1016/j.jhepr.2022.100550
15. Cousins IT, Johansson JH, Salter ME, Sha B, Scheringer M. Outside the safe operating space of a new planetary boundary for per- and polyfluoroalkyl substances (PFAS). Environ Sci Technol. 2022;56(16):11172-11179. doi:10.1021/acs.est.2c02765
16.National Academies of Sciences, Engineering, and Medicine. Guidance on PFAS Exposure, Testing, and Clinical Follow-Up. National Academies Press; 2022. Accessed September 3, 2025. doi:10.17226/26156
Termed “forever chemicals,” PFAS are a class of over 4,700 heterogenous manmade compounds that persist in the environment. Increasing evidence suggests that these ubiquitous compounds are detrimental to human health because they resist environmental degradation and have a significant potential to bioaccumulate, contaminating food chains.