(NaturalNews) Exposure to two industrial chemicals, including a common ingredient in Teflon, significantly increases women's risk of developing arthritis, according to a study conducted by researchers from Yale University, Harvard Medical School, Brigham and Women's Hospital and published in the journal Environmental Health Perspectives.
The two chemicals, PFOA and PFOS, belong to the family known as perfluorinated chemicals (PFCs).
"We found that PFOA and PFOS exposures are associated with higher prevalence of osteoarthritis, particularly in women, a group that is disproportionately impacted by this chronic disease," researcher Sarah Uhl said.
PFCs are used in more than 200 consumer products and industrial processes. In addition to nonstick coatings, they can be found in stain-and water-resistant fabrics and carpets, greaseproof paper food containers (like microwave popcorn bags), and even cosmetics. Because they tend to accumulate in the tissues of animals, including humans, and resist being broken down by biological processes, they are classified as persistent organic pollutants and are considered a major environmental and health concern.
Despite efforts to scale back on the use of PFCs, the chemicals' persistence means that people will continue to be exposed to them for a long time, Uhl said.
"Once they get into the environment they just don't go away," she said. " In people, they last years. So even if we were to reduce the use of these chemicals right away, they're still going to be around and in our bodies for a long time."
Prior studies have linked PFC exposure to elevated levels of LDL ("bad") cholesterol, premature menopause and reduced effectiveness of childhood vaccination (which may imply an effect on the immune system).
PFCs disrupt women's hormones
The new study is the first to examine the connection between arthritis risk and the two chemicals and a representative sample of the U.S. population. Using six years of data from the National Health and Nutrition Examination Survey (NHANES, 2003-2008), the researchers found that the 25 percent of women with the highest exposure to PFOA were approximately twice as likely to suffer from osteoarthritis as the 25 percent with the lowest exposure, even after adjusting for potential confounding factors including age, income and race or ethnicity. The risk was strongest for women between the ages of 20 and 49, and lower for older women.
Notably, the increase in risk was not seen in men.
Osteoarthritis, known colloquially simply as "arthritis," is a degenerative joint disease characterized by stiffness, limited mobility and pain. Scientists remain unsure exactly what causes it, although they believe that inflammation, oxidative stress and abnormal calcium homeostasis all play a role.
Given that uncertainty, it remains unclear why the PFCs studied would increase the risk of arthritis in women but not in men. Uhl suspects that it may have to do with the documented hormone-disrupting effect of PFCs.
"Our hormone systems are incredibly delicate and can be thrown off by tiny doses of hormone-disrupting chemicals," Uhl told Health Day. "And processes like inflammation and cartilage repair are associated with our hormones, and are also associated with osteoarthritis."