Per- and polyfluoroalkyl substances (PFAS) are a large family of man-made chemicals used in industry and consumer products since the 1940s. They are often called “forever chemicals” because their chemical structure makes them highly resistant to breaking down in the environment and the human body. Nearly everyone has some level of PFAS in their system due to widespread use in items that resist water, stains, and grease. Understanding the process of removal involves both clinical and lifestyle strategies, addressing the challenge of the chemical’s persistence.
Why PFAS Remain in the Body
The primary reason PFAS are difficult to eliminate is their molecular structure, which features an exceptionally strong bond between carbon and fluorine atoms. This carbon-fluorine bond is one of the strongest in organic chemistry, resisting metabolism and breakdown by the body’s natural processes. Unlike many other environmental contaminants, PFAS are not broken down or chemically altered by the liver.
Instead of being metabolized, these chemicals accumulate in human tissues, particularly in the blood, liver, and kidneys, a process known as bioaccumulation. The body relies on slow, natural excretion pathways, primarily through urine and to a lesser extent through bile and feces. This slow elimination results in long biological half-lives, which is the time it takes for half of the substance to leave the body.
For some of the most studied compounds, like perfluorooctanoic acid (PFOA) and perfluorooctane sulfonate (PFOS), the half-life in humans can range from approximately two to over four years, respectively. For perfluorohexane sulfonate (PFHxS), the half-life can extend even longer, up to an estimated five to seven years. This prolonged retention means that reducing the body burden requires consistent effort to support elimination pathways and halt new exposure.
Clinical and Emerging Removal Methods
Direct, rapid removal of PFAS is generally limited to highly exposed individuals, relying on invasive clinical procedures. One method studied is therapeutic plasmapheresis, which involves filtering the blood plasma outside the body to remove large molecules. While theoretically effective for removing protein-bound substances like PFAS, it is an invasive procedure not recommended for the general population.
A less invasive, though still clinical, approach is therapeutic phlebotomy, which is the controlled removal of blood, similar to blood donation. A case series involving highly exposed individuals demonstrated that phlebotomy could effectively lower serum PFAS levels, particularly for persistent compounds like PFOS and PFHxS. However, this method is only performed under medical supervision and carries risks, including anemia and iron deficiency.
Emerging research is exploring pharmaceutical interventions, such as the use of bile acid sequestrants like cholestyramine. These medications are designed to bind to substances excreted in bile and prevent their reabsorption in the intestines, thereby increasing fecal excretion. Early observational reports suggest that individuals taking cholestyramine for other reasons had significantly lower PFOA levels, pointing toward a possible mechanism for enhancing removal.
Lifestyle Support for Natural Elimination
The most practical strategy for the general public is to support the body’s natural, slow elimination pathways through targeted lifestyle choices. Since PFAS are primarily excreted through urine, maintaining optimal hydration is foundational, as it supports efficient kidney function. Drinking sufficient water helps ensure that the kidneys can continuously flush waste products from the bloodstream.
Another key strategy focuses on the enterohepatic circulation, where the liver secretes PFAS into the gut via bile, but a large portion is reabsorbed back into the bloodstream. Increasing dietary fiber, especially soluble fiber, can help interrupt this cycle. Soluble fiber, found in oats, beans, apples, and psyllium, binds to the PFAS-containing bile in the gut, preventing reabsorption and ensuring the chemicals are carried out in the stool.
Supporting liver health is also beneficial, as the liver performs the initial work of preparing PFAS for biliary excretion. Consuming foods rich in compounds that support detoxification enzymes, such as those found in cruciferous vegetables like broccoli, may help the body better handle the persistent PFAS compounds.
Moderate physical activity and heat exposure, such as through sauna use, are often recommended as supportive measures, though direct scientific evidence for significant PFAS elimination via sweat remains limited. PFAS are largely protein-bound and hydrophobic, making them more likely to be excreted through urine than sweat glands. Nevertheless, exercise and sweating support overall circulation and lymphatic flow, which aids the body’s waste removal systems.
Reducing Sources of Future Exposure
Efforts to enhance elimination are counteracted if new exposure is not actively prevented, making the reduction of intake the first and most immediate step. Contaminated drinking water is a major source of exposure for many people. Home filtration systems are highly effective, with reverse osmosis (RO) systems and granular activated carbon (GAC) filters being the best options for PFAS removal.
RO systems remove PFAS by forcing water through a semipermeable membrane, while GAC filters trap the chemicals on the surface of activated carbon granules. It is important to select filters certified to reduce PFAS and to replace them according to the manufacturer’s schedule, as saturated filters can release trapped contaminants back into the water.
Another significant source is food contact materials, including non-stick cookware and grease-resistant packaging. Consumers can reduce exposure by replacing non-stick pots and pans—which often contain PTFE, a type of PFAS—with alternatives like stainless steel, cast iron, or glass. Avoiding fast food wrappers, microwave popcorn bags, and other grease-proof containers is also a preventative measure, as these frequently use PFAS coatings. Avoiding household products and fabrics treated for stain or water resistance, such as certain carpets and outdoor gear, limits exposure from indoor dust and air.