Children and teens with high blood levels of certain man-made chemicals used to make nonstick pans also have high levels of cholesterol, according to a new study.
Most people do not have high levels of these chemicals, called perfluoroalkyl acids. The study participants represent a unique case because their drinking water was previously contaminated by these chemicals from a nearby factory; most people are not exposed to such high levels in their drinking water, or through their use of nonstick pans or other products.
Instead, we are all exposed to the these acids because they're present in the smoke released from factories that make nonstick coatings and other products. The chemicals linger in the air and water for years, have become integrated into our food supplies and are now present in at low levels in nearly everyone, researchers say.
By monitoring this highly-exposed group of study participants, scientists say they now have a better idea of how the acids affect health, and the findings should prompt researchers to examine cholesterol counts in people with lower levels of these relatively unstudied chemicals.
The man-made acids are also used to make waterproof fabrics, popcorn bags and food packaging, said study researcher Stephanie J. Frisbee, of the West Virginia University School of Medicine. The two chemicals examined in the new study were perfluorooctanoic acid (PFOA) and perfluorooctanesulfonate (PFOS).
The cholesterol connection
Teenage participants in the study had an average of 29.3 nanograms of PFOA per milliliter of blood, which is about 7.5 times higher than the level in the average teen's blood, according to the study.
The researchers found that participants with higher levels of PFOA in their blood had higher levels of cholesterol. The average total cholesterol for participants was about 161 milligrams per deciliter, but in those with the highest PFOA levels, cholesterol levels were nearly 5 milligrams per deciliter of blood higher than in those with the lowest PFOA levels, the researchers said.
As a result, about 35 percent of the study participants had borderline or high total cholesterol levels, Frisbee said, which means their levels were above the American Heart Association's normal limit of 170 milligrams per deciliter.
"We have observed an association between increasing levels of PFOA and PFOS and cholesterol," Frisbee said. The researchers saw differences in both total cholesterol levels and in low-density lipoproteins (LDLs), the 'bad' cholesterol in children and teens, and that means there are reasons to be concerned about these chemicals, she said.
Previous studies have linked high levels of the chemicals with high cholesterol in adults, Frisbee told MyHealthNewsDaily, and animal tests have shown a possible link to cancer , though that relationship has not been seen in humans.
However, people in the study were exposed to unique circumstances, Frisbee said.
"Our participants had much higher levels of PFOA than is normal," Frisbee said, because the study was conducted on 12,500 youths whose drinking water was contaminated with the chemicals. The participants, who were between ages 12 and 19, are part of the C8 Health Project, which was established to monitor the health of residents in West Virginia's mid-Ohio River Valley after a class-action lawsuit earlier this decade.
These chemicals are absorbed by the liver, which produces cholesterol, said study researcher and C8 Health Project researcher Kyle Steenland, a professor of public health at Emory University.
"There is some animal evidence and biological evidence that lipids in general, cholesterol in particular, may be possibly associated with these chemicals," Steenland said. "Nonetheless, we have no cause yet."
What can be done
Scientists are working on studies that look at people who were exposed to PFOA and follow up with them to determine if PFOA is linked to disease, he said.
There's nothing people can do to eliminate their exposure to PFOA and PFOS because the chemicals are everywhere. And they're persistent PFOA can stay in the body for three and a half years, and PFOS can stay in the body for five years, Frisbee said.
The Environmental Protection Agency is concerned about the potential effects of PFOA and PFOS, according to the agency's website, so it's working with companies such as DuPont, which produces cookware coated with nonstick Teflon, to phase out use of these chemicals by 2015.
However, that doesn't mean the chemicals will disappear, said Olga Naidenko, a senior scientist at the nonprofit Environmental Working Group. Products manufactured overseas may still contain the chemicals, she said.
The study was published in the September issue of the journal Archives of Pediatrics & Adolescent Medicine.
Live Science newsletter
Stay up to date on the latest science news by signing up for our Essentials newsletter.