The latest study shows the compound found in plastic and food packaging can put youngsters at risk for future heart disease.
The list of health problems connected to bisphenol-A (BPA) already includes some serious conditions, from hormone abnormalities to asthma, behavioral problems and obesity. Now, new research suggests that the chemical could be harming children’s kidneys and hearts, independent of the heart issues related to obesity.
For the latest study, published in Kidney International, researchers at New York University analyzed data from 710 U.S. children and teens, ages 6 to 19, who participated in the National Health and Nutrition Examination Survey in 2009 and ’10. Based on previous research that uncovered a relationship between BPA and heart problems in adults, the scientists decided to focus on children, who may even be more vulnerable to the effects of chemicals in their environment. The researchers recorded the children’s BPA levels as measured in their urine and found that kids and adolescents with the highest levels of the compound also had noticeably higher levels of albumin, a protein that builds up when kidneys are damaged, than participants with the lowest levels of BPA.
“This study doesn’t definitively say that BPA causes heart or kidney disease,” says the study’s lead author, Dr. Leonardo Trasande, an associate professor of pediatrics and environmental medicine at the New York University School of Medicine. “The increase in albumin leakage is fairly small, but there are studies in adults that suggest that even that small increment is associated with a higher risk of later heart disease.”
In adults, low levels of albumin in the urine may signal impaired function of blood-vessel linings, which can increase the risk of hypertension, diabetes or heart disease. Very high levels of albumin may be a sign that the kidneys are struggling; healthy organs generally filter out large molecules like albumin, which is why albumin may also be a powerful predictor of subsequent heart failure.
Trasande and his colleagues have only found a correlation, not a causal link between high BPA exposure and high levels of albumin in kids’ urine, but they believe it’s a connection worth investigating further. The link held up even after they adjusted for other factors that could affect kidney disease and heart risk, including the children’s age, race, blood pressure, cholesterol levels, their exposure to cigarettes, family income, overweight status and more.
BPA is commonly used to line food and beverage cans to prevent corrosion, and until recently, it was also used in plastic baby bottles and reusable water bottles. Faced with increasing consumer concern over BPA’s health effects, however, many companies began phasing out BPA, and in 2012 the Food and Drug Administration (FDA) ruled that BPA should no longer be used in baby bottles and sippy cups.
The agency stopped short of banning the chemical altogether as other countries have done, however, citing the inconclusive evidence linking the compound to health problems. The existing studies of BPA in humans compare those with high exposure with those with low exposure, and those types of analyses can be tricky to interpret because people who have large amounts of BPA in their urine could simply be different from the rest of the population in ways unrelated to their BPA exposure. So for now, the FDA considers the data on BPA as mixed, and maintains that “the scientific evidence at this time does not suggest that the very low levels of human exposure to BPA through the diet are unsafe.”
If the findings from the study are replicated, however, they would imply that unhealthy eating habits and lack of exercise aren’t the only risk factors that can affect children’s chances of having heart disease. “Increasingly, we’re identifying environmental chemicals that may be independent contributors to heart-disease risk,” Trasande says. “This study suggests a need for broader perspective in thinking about obesity and heart-disease risk.” And a deeper consideration of how harmful exposure to BPA might be.