Two 'Forever Chemicals' Linked to Faster Biological Aging, With Middle-Aged Men Most Affected

A blood sample drawn from an American adult in 1999 or 2000 has now been put to a new use. Researchers at Shanghai Jiao Tong University went back to that archive, part of the US National Health and Nutrition Examination Survey, and picked out 326 older adults whose blood had been screened for 11 types of PFAS, the synthetic compounds known as forever chemicals. What they found, published in Frontiers in Aging, is a link between two of those compounds and faster biological aging, concentrated in one group: men between 50 and 64.

The two compounds are PFNA, or perfluorononanoic acid, and PFOSA, or perfluorooctanesulfonamide, the latter a precursor of PFOA. Both turned up in roughly 95 percent of the participants, which says something about how widespread exposure is. PFAS levels did not differ significantly between men and women or across age groups. Everyone was carrying them. But the apparent effect on aging did not spread evenly.

To measure aging, the team used 12 recently developed epigenetic clocks. These estimate biological age from DNA methylation patterns rather than from telomere length. In men aged 50 to 64, higher PFNA levels strongly predicted faster epigenetic aging by some of those measures. PFOSA exposure was also tied to different biomarkers of aging. The same pattern did not appear in women, and the researchers say it is not clear why. None of the other PFAS types examined showed a similar link to biological age, which suggests something specific may be going on with these two compounds in this group.

The researchers are careful about what the data can carry. The study shows an association, not cause and effect. Other unknown factors could influence both how much PFAS a person carries and how quickly they age biologically. Epidemiologist Xiangwei Li offers one hypothesis for the male pattern: the aging markers analyzed are heavily shaped by lifestyle factors such as smoking, which could compound the damage from pollutants. His colleague, epidemiologist Ya-Qian Xu, points to midlife as a sensitive biological window, when the body becomes more susceptible to age-related stressors and may respond more strongly to chemical exposure. Both are suspicions offered to explain the result, not findings.

PFAS were developed in the 1940s and 1950s and built around a carbon-fluorine backbone so strong that the chemicals can take up to a thousand years to break down. They turn up in raincoats, non-stick pans, food packaging, upholstery and firefighting foams, wherever a product needs to resist heat, grease, water or fire. Scientists have increasingly tied them to adverse health outcomes. International policies restrict a handful of older legacy PFAS linked to cancer and cardiovascular disease, yet more than 12,000 variants remain in use, and many of the replacements have not been thoroughly studied.

That is the point Li draws from the work: some newer PFAS alternatives are not necessarily low-risk replacements and warrant serious attention regarding their environmental impact. For individuals, he suggests limiting packaged foods and avoiding microwaving fast-food containers. He frames this as a way to reduce risk, not as a proven fix.

The team's next step is to model how PFAS interact with other common pollutants, since the cumulative health risks of chemical mixtures are still poorly understood. The sample here is small and drawn from a single survey cycle, so the open question is whether larger and more recent datasets show the same pattern in middle-aged men, and whether it appears in women.