BPA May Be Linked to Heart Disease Risk
Study Shows Higher Levels of Chemical Mean Higher Risk of Heart Disease
Jan. 12, 2010 - Nearly everyone in the U.S. carries the plastics chemical BPA in their bodies. But those with the highest BPA levels have the highest risk of heart disease, new data confirm.
BPA -- bisphenol A -- is one of the world's most heavily produced chemicals. More than 2.2 metric tons of BPA are used each year to make PVC pipes, epoxy resins that line food cans, food packaging, and drink containers. It can be detected in the bodies of more than 90% of Americans.
Animal studies suggest BPA can have a wide range of health effects. But it's not at all clear whether these animal studies are relevant to humans. In response to calls for data, the CDC in 2003-2004 began testing a representative sample of Americans for BPA as part of the huge NHANES data-collection study.
In 2008, University of Exeter researcher David Melzer, MB, PhD, led a U.K. research team that analyzed the CDC's 2003-2004 data. They found that high BPA levels were linked to a higher risk of heart disease, diabetes, and elevated liver enzymes.
Critics pointed out that the NHANES study looked at so many things, something was bound to seem risky just by chance. Was the BPA finding such a statistical blip?
No, Melzer says. His team analyzed a new set of CDC data collected in 2005-2006. Surprisingly, average BPA levels were 30% lower in the new study. Yet people with the highest BPA levels still had a significantly higher risk of heart disease.
"It is very clear that the connection is still there," Melzer tells WebMD. "It underlines the question mark we found between BPA and human health."
To estimate the size of the risk they found, Melzer calculates that a 60-year-old man in the top third of BPA levels (over 3.5 nanograms/milliliter urinary concentration) has a 10.2% chance of having heart disease. A 60-year-old man in the lowest third of BPA levels (under 1.4 ng/mL urinary concentration) has a 7% chance of having heart disease.
"As urinary concentrations of BPA are an approximate marker of longer-term BPA exposure, we expect these figures underestimate the true effect size. We can’t say by how much, as no long-term exposure data are available," Melzer says.