What happens when you feed families organic foods prepared and stored without the use of any plastic?
Not what you'd expect.
Although it was a small study, University of Washington (UW) researchers found surprising results when one group of families in their study ate only local and organic food catered without the use of plastic. The levels of plastic chemicals in their bodies actually rose, sometimes to alarming levels. "I was very, very surprised at the results," says study author Sheela Sathyanarayana, MD, MPH, assistant professor of pediatrics at UW. The findings suggest food, even healthy food, is a major source of plastic chemical exposure. It highlights the fact that it could be hard for families to completely avoid harmful chemicals based on lifestyle choices.
In the study, published in the Journal of Exposure Science and Environmental Epidemiology, researchers took 10 families and broke them up into two groups: Five families simply received pamphlets giving advice on how to reduce their exposure to phthalates and bisphenol A, hormone-disrupting chemicals associated with brain and reproductive damage in the young and with obesity and type 2 diabetes in adults. The second group agreed to eat only organic foods and drinks prepared and stored without coming into contact with plastic.
To analyze chemical levels in the body, researchers tested family members' urine in both groups during three different periods of the 16-day study. "We fully expected the concentrations to decrease in the catered diet group," Sathyanarayana says.
Instead, the group eating only organic foods prepared, cooked, and stored without plastic saw phthalate levels soar to levels up to 2,400 percent higher than they were at the start of the study; the children's levels were the highest.
The unexpected jump in chemical exposure caused the researchers to go back and test as much food used in the organic group as possible. They identified high-fat dairy products and contaminated organic coriander as the source of the phthalates.
"We used to think of plastic bottles or other plastic products as the biggest sources of exposure to these chemicals, but it is really likely that diet is a significant contributor to phthalate and BPA concentrations," Sathyanarayana says. "There is probably contamination higher up in the food chain that we don't know about and that manufacturers do not know about."
The small study highlights a larger food-system threat. Most of the 80,000 chemicals in use today have never been tested for long-term impact on human health. How they wind up in food, or how all of the different chemicals we're exposed to daily mix and interact inside of our bodies, is poorly understood.
"This study is a real eye-opener in that it suggests it may be impossible to make choices as a consumer that are guaranteed to prevent exposure to these chemicals," says John Meeker, ScD, associate professor of environmental health sciences at the University of Michigan School of Public Health. He was not involved with this study.
It's not just an America problem, either. In February 2013, the World Health Organization and the United Nations Environment Programme dubbed endocrine disruptors like BPA and phthalates a global threat for their suspected roles in chronic diseases, developmental problems, infertility, and certain cancers.
Since the group of families receiving the educational materials didn't see a significant drop in chemical levels either, Sathyanarayana says that without industry-wide or federal regulation, the efforts to lower chemical body burdens may be futile.
So does this study mean it's time to ditch organic diets? "No, eating organic still reduces pesticide exposure and also ensures non-GMO foods," Sathyanarayana says. "I think the advice I would give is to focus on fresh foods and a low animal-fat diet to reduce exposures to these chemicals."