The “forever chemicals” known as PFAS appear to be aging men faster in their 50s and early 60s, a new study found.
Called forever chemicals due to the years it takes for them to break down, perfluoroalkyl and polyfluoroalkyl substances are present in the blood of an estimated 98% of Americans, according to the National Academies of Sciences, Engineering, and Medicine.
Epigenetic aging — a measurement of one’s biological age instead of chronological age — was most advanced in men, according to the study.
“The associations between PFAS exposure and accelerated epigenetic aging were strongest in men aged 50 – 65,” said senior study author Xiangwei Li, a professor of epidemiology at China’s Shanghai Jiao Tong University School of Medicine, in an email.
“In younger men and those over 65, the associations were weaker and generally not statistically significant,” Li said. “We observed some associations in women, but they were generally smaller and less consistent than those seen in middle-aged men.”
The findings indicate a “sex-specific effect” that can be expected for chemicals that disrupt the endocrine system, a vital network that regulates key bodily functions such as growth, metabolism, mood and reproduction, said Jane Muncke, managing director and chief scientific officer at the Food Packaging Forum, who was not involved in the study.
The forum is a nonprofit foundation based in Zurich, Switzerland, that focuses on science communication and research on plastics and other chemicals used in industry.
In men, the accumulation of PFAS may lower testosterone levels, impair sperm quality and increase risks of testicular and kidney cancers.
Earlier studies show women appear to eliminate certain PFAS faster than men due to pregnancy, breastfeeding and menstrual blood loss. Studies have also found the difference in PFAS accumulation between women and men narrows after menopause.
While the new study’s results are interesting, they “cannot be interpreted as cause-and-effect but rather are puzzle pieces, or building blocks, to establish biological plausibility,” Muncke said in an email.
The American Chemistry Council, which represents the industry, told CNN the “exploratory” study was based on a small sample of older adults using data collected more than 20 years ago.
“This paper does not provide evidence that PFAS exposure causes aging, nor does it change the extensive body of scientific and regulatory work already underway to understand and manage specific PFAS of potential concern,” Tom Flanagin, the council’s senior director of communications, said in an email.
The study, published Thursday in the journal Frontiers in Aging, used public data from a randomly chosen group of 326 older women and men enrolled in 1999 and 2000 in the US National Health and Nutrition Examination Survey.
Blood samples gathered at the time were examined for the presence of 11 types of PFAS chemicals. The DNA methylome — an epigenetic marker regulating gene expression — was also measured in the blood cells of the participants.
For this study, researchers fed these DNA data into a dozen “epigenetic clocks,” also known as biological clocks, to estimate the aging of blood and other tissues in the participants.
Used since the 1950s to make consumer products nonstick, oil- and water-repellent and resistant to temperature change, PFAS chemicals have been linked to serious health problems, including cancer, fertility issues, high cholesterol, hormone disruption, liver damage, obesity and thyroid disease.
The dangers of so-called legacy PFAS, such as perfluorooctanesulfonic acid, or PFOS, perfluorooctanoic acid, or PFOA, and perfluorohexane sulfonate, or PFHxS, are so well-known they have been targeted for elimination worldwide under the 2001 Stockholm Convention on Persistent Organic Pollutants, a global treaty that would reduce toxic chemicals that bioaccumulate in organisms and the environment. The United States has signed the treaty but has not ratified it.
Under the Biden administration, the US Environmental Protection Agency planned to impose stricter guidelines about legacy PFAS levels, including labeling them as “hazardous substances” under the US Superfund law. However, those plans have been rolled back or delayed under the Trump administration.
The chemical industry has created many other forms of PFAS that have not been as widely studied. Those chemicals may well have the same biological impacts as the rest of the PFAS family — and that’s what the new study found, Li said.
“Our results suggest that some less-studied PFAS — namely perfluorononanoic acid (PFNA) and perfluorooctanesulfonamide (PFOSA) — may also have biologically meaningful associations,” Li said.
In fact, the study found higher concentrations of PFNA and PFOSA were strong predictors of faster epigenetic aging in men between 50 and 64 years of age but not in women.
Despite these findings, “it’s important not to panic,” Li said. “Our study shows associations, not proof of causation. PFAS exposure is widespread, and complete avoidance is unrealistic.
“However, reducing exposure where feasible — such as using certified water filters, following local water advisories, and minimizing contact with stain- or grease-resistant materials — may be reasonable steps,” he added. “At the same time, meaningful risk reduction depends largely on regulatory action and environmental cleanup, since many exposures occur at the community level.”
Get inspired by a weekly roundup on living well, made simple. Sign up for CNN’s Life, But Better newsletter for information and tools designed to improve your well-being.