Exposure to ‘forever chemicals’ may raise diabetes risk in middle-aged women: study

Exposure to the industrial toxins known as “forever chemicals” may be associated with an increased risk of developing diabetes for middle-aged women, a new study has found.

Some types of per-and polyfluoroalkyl substances (PFAS) — an umbrella group for thousands of compounds — could disrupt the regulatory behavior of certain protein molecules and cause greater susceptibility to diabetes among this group, according to the study, published in the journal Diabetologia on Monday.

That’s because many of these chemicals have molecular structures similar to those of naturally occurring fatty acids, meaning that they have similar chemical properties and impacts on the human body, the authors explained.

“Higher serum concentrations of certain PFAS were associated with higher risk of incident diabetes in midlife women,” the researchers, from the University of Michigan, said in a statement. “The joint effects of PFAS mixtures were greater than those for individual PFAS, suggesting a potential additive or synergistic effect of multiple PFAS on diabetes risk.”

Fatty acids act on a class of proteins called “peroxisome proliferator-activated receptors,” which serve as fat and insulin sensors and are the main controllers of the body’s fat and glucose levels, according to the study. But because some types of PFAS could potentially interact with these receptor proteins, they could also disrupt their regulatory behavior and increase the risk of diabetes.

Experimental studies with cell cultures have already suggested that exposure to high levels of PFAS in some people could interfere with the function of these proteins, by triggering increased fat cell production and changing fat and sugar metabolism, the authors noted.

PFAS have already been linked to a variety of illnesses including thyroid and testicular cancer. Dubbed “forever chemicals,” they are known for their propensity to linger in the human body and in the environment and are resistant to most processes that naturally break down other chemicals.

While they are most notorious for their presence in certain firefighting foams and industrial discharge, PFAS are also key ingredients in a variety of household products, such as nonstick pans, waterproof apparel and cosmetics.

Recent research has suggested that exposure to PFAS may be associated with preeclampsia, altered levels of liver enzymes, increased blood fats, reduced antibody response to vaccines and lower birth weight, but causal relationships to these issues have yet to be established, according to the Diabetologia study.

The authors drew a sample group from the Study of Women’s Health Across the Nation, a database co-sponsored by the National Institute on Aging, the National Institute of Nursing Research, the National Institutes of Health, Office of Research on Women’s Health and the National Center for Complementary and Alternative Medicine.

They first selected a total of 3,302 premenopausal participants aged 42-52 who had been recruited for studies at seven U.S. locations in 1996-1997, and then narrowed down that pool through a 2016 “Multi-Pollutant Study” that evaluated blood and urine samples for environmental contaminants.

After excluding women who already had diabetes and other participants for whom insufficient data was available, they ended up with a final sample of 1,237 women with a median age of 49.4 years, who had been observed from 1999-2000 through 2017.

In total, the authors identified 102 cases of incident diabetes per 17,005 “person-years” or six cases per 1,000 “person-years” — a medical measurement for the number of years multiplied by the members of an affected population.

The researchers grouped women into high-, middle- and low- exposure groups according to their blood concentrations of PFAS, and then calculated a “hazard ratio” by comparing the incidence rate of diabetes in the high and middle groups with that of the low one, per the study.

They found that women in the high-exposure group were 2.62 times more likely to develop diabetes than those in the low category, with increased risk for each individual type of PFAS ranging from 36 to 85 percent, according to the study.

This last finding suggests a potential additive or synergistic effect of multiple types of PFAS on diabetes risk, the authors explained.

Looking at the demographics of those who developed diabetes, the authors found that these women were more likely to be Black, less formally educated, less physically active, have a higher energy intake and from Southeast Michigan — a more socioeconomically disadvantaged area.

The authors called for relevant agencies to change the ways they govern drinking water, while urging clinicians to learn about PFAS as an unrecognized risk factor for diabetes. They also advised that PFAS may need to be regulated as a class — a proposal that has long met with vehement objection from companies that produce and use these compounds.

“Reduced exposure to these ‘forever and everywhere chemicals’ even before entering midlife may be a key preventative approach to lowering the risk of diabetes,” the authors said in a statement. “Policy changes around drinking water and consumer products could prevent population-wide exposure.”