BPA and the Potential Dangers of Packaged Foods

Summary
Packaged food and drinks are assumed to be safe by most consumers. However, the chemicals used in the plastic packages and containers (bisphenol A and DEHP) can enter the human body; and these chemicals can be a health hazard. The current study showed that three days of eating food with limited food packaging resulted in a substantial decrease in the metabolic end-products of these chemicals. The results of this study suggest that reducing the use of plastic in food packaging and eating fresh food from non-plastic containers would reduce health hazards.

Introduction
Bisphenol A (BPA) is an industrial chemical used in producing plastic goods and food packages. Phthalates are another class of chemicals used to produce food packages. Animal and human population-based studies show that, in humans, the endocrine system can be affected by these chemical agents. In one study, it was found that metabolites of these chemicals were present in over 90 percent of urine samples tested. Information about the exposure sources and the role of diet will help in providing guidelines to consumers, with hopes of reducing exposure. The current study assessed changes in urinary metabolite levels of BPA and phthalates during and after a three-day dietary intervention, substituting packaged food with fresh food.

Methodology
* The study included 20 participants from five families that frequently consumed canned foods.
* Each participant provided a urine sample on days one and two (before diet modification), on days four and five (during the fresh food diet) and on days seven and eight (after diet modification).
* A specific diet was prepared by a caterer and consumed by the participants. The containers and storage of food were designed so that contact with plastic was minimal.
* Urine samples were tested for metabolites of Bisphenol A (BPA) and phthalates. Levels were analyzed for differences between genders, between adults and children, and for effects of belonging to the same family.

Results
* Compared to another study by the Center for Disease Control and Prevention in 2007-2008, the levels of BPA and metabolites of phthalates in urine were higher in children and adults even before the diet change.
*  While adults showed higher urine levels of one metabolite, children had higher levels of the other three metabolites in their urine. There was no significant difference between the results of the males and females. Individual behavior was found to be more important than a shared home environment for families.
* The mean reduction in urine metabolites during the modified diet period was 66 percent for Bisphenol A (BPA). The mean reduction for various metabolites of phthalates in urine during the modified-diet period was about 53 percent.
* After the return to regular diets, the levels of these chemicals returned to the levels noted before intervention.

Next steps/Shortcomings
The participants were few and the study lasted just one week. The findings might not be representative of all populations. The study interviewed and selected people who used packaged food frequently, which might have created a bias. There is a possibility that the values of urinary metabolite of these chemicals might be high in people not consuming packaged food. So, these findings cannot be generalized. Also the intervention could not account for exposure to every dietary source of phthalates and BPA, since contamination can also easily occur during pre-market processing of food.

Conclusion
This study showed that packaged food might not be a healthy food option. The packaging material contains chemicals like Bisphenol A and phthalates, which are absorbed by the human body. Its metabolites are detectable in the urine sample. These chemicals are known to affect the hormonal system of the body and are known to be a threat to health. Eating fresh food and consuming it from non-plastic containers dramatically reduced the levels of these chemicals in urine. But the effect was short-lived. Potential sources of exposure identified were meals prepared outside the home, canned foods, canned soda, frozen dinners, drinking from polycarbonate water bottles, and microwaving in plastic containers. Avoiding use of plastics for food packaging and avoiding preserved food in plastic containers are two ways of reducing the health hazard.

For More Information:
Food Packaging and Bisphenol A and Bis(2-Ethyhexyl) Phthalate Exposure: Findings from a Dietary Intervention
Publication Journal: Environmental Health Perspectives, March 2011
By Ruthann A. Rudel; Janet M Gray; Silent Spring Institute, Newton, Massachusetts and Breast Cancer Fund, San Francisco, California
*FYI Living Lab Reports Are Summaries of the Original Research.