BPA and Obesity: Is This Connection Real?

Best Evidence Review of Association Between Urinary Bisphenol A and Obesity in Children and Adolescents

The Study

Trasande L, Attina TM, Blustein J. Association between urinary bisphenol A concentration and obesity prevalence in children and adolescents. JAMA. 2012;308:1113-1121.

The Background

Bisphenol A (BPA) has generated much attention in the past several years regarding its potential deleterious effects on health, but the evidence implicating BPA in promoting human disease is thin. In the current study, urinary concentrations of BPA above the first quartile of values were associated with a higher rate of obesity among children and adolescents, even after adjustment for multiple confounding variables. Regulators should continue to work with industry to evaluate safer alternatives to this chemical.

The potential risk associated with BPA is one of the hottest topics in public health and toxicology. While the precise health dangers of BPA are not clearly defined at this time, the ubiquity of the BPA compound is undeniable. Approximately 6 billion pounds of BPA are produced annually.^[1] BPA is used in a variety of ways, but health concerns associated with BPA are primarily related to its use in contact with food and liquids consumed by humans, particularly in its use as a liner in food cans and other storage containers as well as in pipes that supply drinking water.

Human exposure to BPA, then, is primarily through diet. BPA is excreted rapidly in the urine, with a half-life that is as short as 4 hours. However, it appears that fat acts as an efficient storage center for BPA. In a study of over 2500 individuals aged 6 years or older, BPA was detectable in the urine of 92.6% of participants.^[2] Mean BPA concentrations were lower among Mexican Americans compared with non-Hispanic whites and black individuals, and children had higher mean BPA levels than adults did.

BPA has been associated with a number of serious medical conditions. It is recognized that BPA is an efficient activator of estrogen receptors, even during the fetal and neonatal periods.^[3] BPA has been demonstrated to affect fertility and pregnancy outcomes, primarily in animal studies.^[4] Moreover, a systematic review found a positive association between BPA concentrations during pregnancy and the risk for autism spectrum disorders.^[5] BPA was also significantly associated with externalizing behaviors related to attention-deficit/hyperactivity disorder.

The proestrogenic effect of BPA can also carry consequences for metabolism. Two studies have found weak evidence that supports an association between higher BPA concentrations and later breast and pubic hair development.^[6,7] The evidence on BPA has also been associated with obesity among adults. In one large study, individuals in the highest 3 quartiles of BPA concentration had adjusted risks for obesity that were 60%-85% higher compared with adults in quartile 1.^[8]

Could the association between BPA and obesity also apply to children and adolescents? The current study investigates this issue.