Exposure to a common group of chemicals thought to last almost forever may be connected to an increased risk of diabetes for middle-aged women, according to a new study.
Published in Diabetologia, the scientific journal of the European Association for the Study of Diabetes, on Monday, the study described how in a cohort of more than 1,000 women, the onset of diabetes was associated with higher levels of exposure to PFAs, a group of more than 4,700 synthetic chemicals.
First developed in the 1940s, per- and polyfluoroalkyl substances, known as PFAS, are found in countless types of everyday products such as water-resistant clothing, stain-resistant carpets and non-stick cookware, as well as in industries such as construction, electronics and the military. They are useful because of their properties in resisting water, oil and heat.
But they also are often called “forever chemicals” because they include linked carbon and fluorine atoms, which is one of the strongest bonds in chemistry, meaning PFAS do not break down easily in our environment.
PFAS have been detected in our water, in the ground, and in human and animal bodies themselves, persisting in our environment far beyond the products they are used in. But their full impact on our health is not completely understood, making them a huge concern for scientists, according to a press release.
In this new study, scientists drew data from a cohort called the Studyxjmtzyw of Women’s Health Across the Nation (SWAN), an ongoing study group that focused on cis women in midlife to see the before and after health outcomes for the menopause transition. Women were recruited for the cohort in the U.S. between 1996-1997, and went for follow-up testing multiple times in the following years.
In 2016, SWAN analyzed blood and urine samples from a smaller cohort for the SWAN Multi-Pollutant Study (SWAN-MPS) which had started in 1999-2000 to test for the presence of environmental chemicals, including seven PFAS. The women gave urine and blood samples and were monitored from 1999 to 2017.
To study the impact of PFAS exposure, researchers looked at 1,237 women in the SWAN-MPS cohort who were all between the ages of 45-56 years at the start of the study period and had no history of diabetes.
Researchers were searching for incident diabetes, which is when a patient with no history of diabetes develops new-onset diabetes abruptly.
Between 1999 and 2017, scientists observed that 102 women had developed diabetes out of the 1,237.
Researchers organized participants into three groups, based on whether they had high, middle or low exposure to PFAS based on their samples. When they compared participants in the high and middle groups to those in the low exposure group, they found that the incidence rate of diabetes was higher in the high and middle exposure groups.
"Higher serum concentrations of certain PFAS were associated with higher risk of incident diabetes in midlife women,” researchers stated.
If participants had exposure to more than one type of PFAS, the risk increased even more, researchers found.
Women who were in the high exposure group for all seven PFAS included in the study were more than two and a half times more likely to develop diabetes than those with low exposure.
“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,” researchers explained.
Previous studies have observed associations between PFAS exposure and altered levels of liver enzymes, increased blood fats, low birth weight and even decreased antibody response to vaccines, according to the release.
It’s unknown if the results from this new study are applicable to men as well, but if they are, that would mean that around 370,000 cases out of the 1.5 million Americans diagnosed with onset diabetes each year might be connected to PFAS exposure, the release stated.
Those who developed diabetes in the cohort were also more likely to be Black, come from a socially and economically disadvantaged area, be less physically active and have a higher body mass index, factors which may speak to the ways that social and economic forces combine to increase health risks for disadvantaged groups in society.
"Reduced exposure to these ‘forever and everywhere chemicals’ even before entering midlife may be a key preventative approach to lowering the risk of diabetes,” researchers stated. “Policy changes around drinking water and consumer products could prevent population-wide exposure.”
Because of how many types of PFAS exist, they suggest that policy-makers consider PFAS as a class when making regulations, instead of trying to regulate each specific one.
