Bisphenol A, Diet and Obesity: Exposure Measurement and the Relationship Between Diet and Bisphenol A

Abstract

Diet is considered the primary source of BPA exposure, due to the use of BPA in polycarbonate plastics and epoxy resins used in food packaging. Existing human research has major limitations and the cost of serum and urinary BPA assay remains a challenge in evaluating BPA exposure and chronic disease outcomes. Despite the fact that diet is a vehicle for BPA exposure, few studies have considered whether dietary composition alters the toxicokinetics of BPA. Epidemiological studies have also not addressed diet as a potential confounder or effect modifier even though diet is associated with both disease risk and BPA exposure. The Urinary Biomarkers of Dietary Intake (UB-Diet Study) was developed to evaluate the feasibility of using questions that target intake of known dietary sources of BPA to estimate BPA exposure. Predicted BPA exposure levels from the BPA exposure assessment module (BEAM) were compared to multiple spot urine samples. Food records were also collected on the days that urine samples were collected to further evaluate the relationship between diet and urinary BPA levels. Reported macronutrient and food group servings were compared to urinary BPA levels. The BEAM data was not able to accurately predict participants' urinary BPA levels. Recent canned food intake was associated with urinary BPA levels, but only explained approximately one-fifth of the variability in urinary BPA levels and several participants who reported consuming no canned foods had high urinary BPA levels. The study findings suggest that BPA levels may be positively associated with higher caloric and fiber intake, and intakes of vegetables, refined grains and red meats, and inversely associated with total fat intake. More research is needed to characterize sources of BPA exposure, to evaluate the role of diet in the toxicokinetics of BPA and to determine if chronic low level BPA exposure poses any health risk.