Posted: Sep 4, 2012 9:03 PM
"Even at the low exposure levels of PFOAs found in most Americans, there is a positive association between increasing levels of PFOAs and cardiovascular disease," says researcher Anoop Shankar, MD, PhD, MPH.
Shankar looked at data on more than 1,200 men and women, on average in their 50s, collected from the National Health and Nutrition Examination Survey (NHANES).
PFOA is used to make lubricants, polishes, paper and textile coatings, food packaging, and fire-retardant foams.
Levels of this chemical have been found in the blood of more than 98% of Americans. The chemical stays in the body for years.
The study is published in the Archives of Internal Medicine.
While other studies have found a link between PFOA and heart disease risk factors, such as high blood pressure, fewer have looked at levels of the chemical and actual cardiovascular disease, which is defined as heart disease, heart attack, or stroke diagnosed by a doctor.
Even so, Shankar stresses that he found only a link, not cause and effect.
The men and women were divided into four groups, depending on blood levels of the chemical.
They reported if they had heart disease, heart attack, or stroke. They were tested for peripheral artery disease, a narrowing of blood vessels outside the heart due to plaque buildup.
As blood levels of PFOA increased, so did cardiovascular disease and peripheral artery disease, Shankar found.
Compared to those in the lowest PFOA group, those in the highest were two times as likely to have cardiovascular disease and nearly two times as likely to have peripheral artery disease.
Shankar says, however, that the heart disease may be driving the PFOA level, not vice versa. "People with heart failure have poor kidney function; it is possible [these findings are] due to retaining more PFOAs in those with severe heart disease."
"It is [also] possible that the association we are observing is due to a third, yet unknown, unmeasured factor," he says.
It's too soon, he says, to suggest avoiding PFOA to reduce cardiovascular disease risk.
Paul Pestano, a research analyst with Environmental Working Group, says a growing body of evidence suggests that PFOA exposure is associated with risk factors linked to heart disease.
But because the new study is a "snapshot in time," he says, "It doesn't really prove causality."
People who are concerned, Pestano says, can focus on reducing exposure to the chemical. For instance, don't use products made with Teflon.
In a statement, Marie Francis of the American Chemistry Council, an industry group, says: "This study has several weaknesses that the authors themselves have pointed out."
Francis also reinforces that the study only shows an association and is not "causal."
The council is involved in efforts to develop new chemicals similar to PFOA that limit the health and environmental impact, according to a news release.
The EPA is also involved in efforts to reduce the impact of the chemical on the environment.