Chemical, already banned from sippy cups and baby bottles, still used in soda cans
Researchers at NYU School of Medicine
have revealed a significant association between obesity and children
and adolescents with higher concentrations of urinary bisphenol A (BPA),
a synthetic chemical recently banned by the U.S. Food and Drug
Administration (FDA) from sippy cups and baby bottles. Still, the
chemical continues to be used in aluminum cans, such as those containing
soda.
The study appears in the September 19 issue of
JAMA (
Journal of the American Medical Association), dedicated to the theme of obesity.
"This is the first association of an environmental chemical in
childhood obesity in a large, nationally representative sample," said
lead investigator Leonardo Trasande, MD, MPP, associate professor of
pediatrics and environmental medicine. "Our findings further demonstrate
the need for a broader paradigm in the way we think about the obesity
epidemic. Unhealthy diet and lack of physical activity certainly
contribute to increased fat mass, but the story clearly doesn't end
there."
BPA, a low-grade estrogen, was until recently found in plastic
bottles labeled with the number 7 recycling symbol, and is still used as
an internal coating for aluminum cans. Manufacturers say it provides an
antiseptic function, but studies have shown the chemical disrupts
multiple mechanisms of human metabolism that may increase body mass. BPA
exposure has also been associated with cardiovascular disease, breast
cancer, prostate cancer, neurological disorders, diabetes and
infertility.
"In the U.S. population, exposure [to BPA] is nearly ubiquitous,
with 92.6 percent of persons 6 years or older identified in the
2003-2004 National Health and Nutrition Examination Survey (NHANES) as
having detectable BPA levels in their urine. A comprehensive,
cross-sectional study of dust,
indoor and outdoor air, and solid and
liquid food in preschool-aged children suggested that dietary sources
constitute 99 percent of BPA exposure," the investigators wrote.
Using a sample of nearly 3,000 children and adolescents, ages 6
through 19 years, randomly selected for measurement of urinary BPA
concentration in the 2003-2008 NHANES, Dr. Trasande and his co-authors,
Jan Blustein, MD, PhD, and Teresa Attina, MD, PhD, MPH, examined
associations between urinary BPA concentrations and body mass.
After controlling for race/ethnicity, age, caregiver education,
poverty to income ratio, sex, serum cotinine level, caloric intake,
television watching, and urinary creatinine level, the researchers found
children with the highest levels of urinary BPA had 2.6 times higher
odds of being obese than those with the lowest measures of urinary BPA.
Among the participants with the highest levels, 22.3 percent were obese
compared with 10.3 percent of the participants with the lowest levels.
Further analyses showed this association to be statistically
significant in only one racial subpopulation, white children and
adolescents. The researchers also found that obesity was not associated
with exposure to other environmental phenols commonly used in other
consumer products, such as sunscreens and soaps.
"Most people agree the majority of BPA exposure in the United States
comes from aluminum cans," Dr. Trasande said. "This data adds to
already existing concerns about BPA and further supports the call to
limit exposure of BPA in this country, especially in children. Removing
it from aluminum cans is probably one of the best ways we can limit
exposure. There are alternatives that manufacturers can use to line
aluminum cans."
The researchers wrote in their study that advocates and policy
makers have long been concerned about BPA exposure. "We note the recent
FDA ban of BPA in baby bottles and sippy cups, yet our findings raise
questions about exposure to BPA in consumer products used by older
children. Last year, the FDA declined to ban BPA in aluminum cans and
other food packaging, announcing 'reasonable steps to reduce human
exposure to BPA in the human food supply' and noting that it will
continue to consider evidence on the safety of the chemical. Carefully
conducted longitudinal studies that assess the associations identified
here will yield evidence many years in the future."
