The chemicals in question are perfluorooctanoic acid (PFOA), currently used to make pans and fabric finishes, and perfluorooctane sulfonic acid (PFOS), which had been used in Scotchguard finishes until it was banned in 2005. The chemicals build up in our bodies and are so persistent in the environment that they have even been detected in the blood of Arctic polar bears.
THE DETAILS: In the first study, published online in Environmental Health Perspectives, researchers analyzed cholesterol levels and blood-serum levels of PFOS, PFOA, and two other related chemicals in 2,094 participants of the National Health and Nutrition Examination Survey (NHANES) conducted by the Centers for Disease Control and Prevention. After adjusting for factors such as age, race, sex, weight, and physical activity, the researchers found a positive association between these chemicals and total and LDL (bad) cholesterol levels.
A second study, published in the American Journal of Public Health, focused on residents living near a West Virginia-Ohio watershed that had been heavily contaminated with PFOA and PFOS by a nearby DuPont factory that manufactured both chemicals. That study reached the same conclusions: People with high levels of PFOA and PFOS in their bodies also had higher total and LDL cholesterol levels, even after controlling for demographic, lifestyle, and dietary factors.
WHAT IT MEANS: PFOA and PFOS have already been linked to both male infertility and female infertility, as well as low birth weight in babies. These studies don't definitively prove that chemicals used to repel stains and grease are causes of high cholesterol, says Kyle Steenland, PhD, professor at Emory University's Rollins School of Public Health and lead author of the American Journal of Public Health study. But, he says, they do raise questions about what these chemicals are doing to our bodies.
The NHANES studies found that 98 percent of all participants had detectable levels of these chemicals in their bodies, partly because they take so long for our bodies to eliminate once they are exposed to them. It takes 5.4 years for your body to get rid of PFOS and 3.8 years to get rid of PFOA. While inside you, Steenland says, the chemicals bind to proteins in your blood. "We can't tell whether PFOA causes high cholesterol, or if it correlates to something in the body that causes you to retain higher levels of cholesterol," he says. Either way, it may turn out that all these chemicals designed to make life more water-resistant and stain-repellent could mean higher levels of heart disease down the road.
If you're concerned about your cholesterol levels, here are some ways to avoid these chemicals:
• Switch to better pans. Pots, pans, and bakeware coated with a nonstick finish were manufactured using PFOA. The weight of the evidence suggests that there is no PFOA in the final product, says Steenland. However, he adds, there's a chance that PFOA can form if you overheat the pans to scorching. No need to ditch all your nonstick pans this instant (unless you have pet birds; heating the pans releases fumes that are lethal to feathered pets). Use them until they start to wear out and replace them with safer stainless steel, cast iron, or glass cookware. When using nonstick products, don't let them overheat or scorch, and don't leave them unattended on the stove.
• Make your own "microwave" popcorn. Microwave popcorn bags are lined with a PFOA-based material to prevent all that unhealthy butter—or whatever's coating those kernels—from soaking through. According to a study published last year in Environmental Science and Technology, the levels of PFOA detected in microwave popcorn bags were, in some cases, six times higher than the levels of PFOA detected in nonstick pans. The truth is, there's no need to buy microwave popcorn. You can pop ordinary popcorn kernels in a paper bag or microwave-safe bowl, no oil or chemical coatings needed.
• Avoid fast food. The same material used to line microwave popcorn bags is used on pizza boxes and in fast-food sandwich wrappers. In 2006, Canadian researchers tested fast foods for PFOA residues and found the highest concentrations in egg breakfast sandwiches, french fries, chicken nuggets, and fish burgers. By some estimates, the wax paper used in pizza delivery boxes and other fast-food wrappers together with the linings used in microwave popcorn bags can account for as much as 20 percent of our exposure to PFOA.
• Be a neat freak. PFOS was used in Scotchguard until 2005, when it was banned over concerns that it can cause cancer. New fabric treatments are similar in chemical makeup but haven't been fully tested for health effects, so rather than rely on chemicals to keep your furniture and clothes clean, be a neat freak. Or, just don't eat on your furniture. It's better for your mental and physical health to eat at a dinner table and enjoy your meal, not overeat mindlessly in front of the TV.