BPA Linked to Heart Disease
Bisphenol-A (BPA), an industrial chemical used primarily in plastics and canned food linings, continues to be linked to multiple health conditions. A new study published online in the January 12 edition of PloS ONE confirms a previous link found between exposure to BPA and heart disease.
Researchers from the University of Exeter in England combined and reviewed data from the 2003-2004 and the 2005-2006 National Health and Nutrition Examination Surveys (NHANES) conducted by the Centers for Disease Control and Prevention. Both analyses revealed a link between concentrations of bisphenol-A in urine samples and risk of cardiovascular disease.
Urinary concentrations of BPA are an approximate marker of longer-term BPA exposure.
Out of the 2,605 people found with detected urinary BPA levels, the researchers identified 159 people who were also diagnosed with cardiovascular disease. Extrapolating the data, the scientists predict that men over 60 with high BPA exposure have about a 10% elevated risk of developing heart disease compared with 7% of men with less exposure.
The exact mechanism of the link to cardiovascular disease is unknown, but is likely a result of a couple of different factors. For example, a 2008 study found that BPA suppresses a hormone that protects people from heart attacks and type 2 diabetes. In a separate study, mice exposed to BPA caused an increase in insulin output from the beta cells of the pancreas – another risk factor for heart disease and metabolic syndrome. The metabolism of BPA in the body can also lead to oxidative stress and endothelial cell damage.
“We now have two completely separate samples with completely different people,” says study coauthor David Melzer, an epidemiologist at the Peninsula Medical School in Exeter. The new work shows that the previous finding of a link “wasn’t a statistical blip.”
Some good news about BPA did come to light as a result of this study. The levels of BPA found in the later survey was about one third lower than in the 2003-2004 participants. While the true cause is unknown, it is likely due to manufacturers decreasing or eliminating the use of BPA in plastics and food containers and from public awareness of the health conditions that can result from long-term exposure to BPA.
In addition to plastics and liners that come in contact with foods and beverages, scientists are continuing to look at other areas that may expose people to BPA in the course of daily life. Household dust, carbonless cash register receipts, and PVC pipes. An FDA safety assessment that was scheduled for release last year is still pending.
The National Institute of Environmental Health Sciences (NIEHS) offers these tips for reducing exposure to BPA:
· Don’t microwave polycarbonate plastic food containers. Polycarbonate is strong and durable, but over time it may break down from overuse at high temperatures.
· Polycarbonate containers that contain BPA usually have a No. 7 on the bottom, although not all containers with a No. 7 contain BPA.
· Reduce your use of canned foods.
· When possible, opt for glass, porcelain, or stainless steel containers, particularly for hot food or liquids.
· Use baby bottles that are BPA-free.