A new study has reported that eliminating packaged and restaurant food from the diet can substantially reduce exposure to certain estrogenic compounds that have been reported to increase risk of breast cancer. The study was designed to evaluate the contribution of food packaging to bisphenol A (BPA) and bis(2-ethylhexyl) phthalate (DEHP) exposure. BPA and DEHP are chemicals widely used in plastics and resins for food packaging. For example, BPA is used to line metal food and beverage cans. BPA and DEHP have been reported to be associated with endocrine disruption (estrogenic activity) in animal experiments and in some human studies. Exposure sources have been estimated for humans, but the relative contribution of dietary exposure to total intake has not been determined.

The study was designed to estimate the contribution of food packaging to exposure by measuring BPA and phthalate metabolites in the urine of study participants before, during and after a non-packaged foods dietary intervention. The study, which took place in January 2010, included 20 participants in five families who self-reported use of canned and packaged foods. Participants initially ate their usual diet, then consumed only fresh foods (not canned or packaged in plastic and no restaurant meals) for three days, after which they returned to their normal diet. Evening urine was collected from participants over eight days and combined into pre-intervention, intervention period, and post-intervention samples.

Urinary levels of BPA and DEHP metabolites were found to decrease significantly during the fresh foods intervention period. For example, average BPA was 3.7 ng/mL before the fresh food intervention compared to 1.2 ng/mL during the intervention period. The intervention reduced average concentrations of BPA by 66% and DEHP metabolites by 53% to 56%. Maximum BPA levels were reduced by 76% and maximum DEHP metabolite levels were reduced by 93% to 96%. The authors conclude that BPA and DEHP exposures were substantially reduced when participantsí diets were restricted to food with limited packaging.