You Are What You Eat Reducing Chemical Exposures Through Diet
Hormone-altering or endocrine-disrupting chemicals are all around us—in our household dust, in our personal care products and in our food. They’re also, as scientists from the Centers for Disease Control and Prevention discovered years ago, in most of our bodies. But a recent study from Silent Spring Institute in Massachusetts (silentspring.org) shows we can drastically reduce our consumption of the endocrine disruptors Bisphenol A (BPA) and di(2-ethylhexyl) phthalate (DEHP) by making a few basic changes in our dietary practices. These include: choosing fresh fruits and vegetables, microwaving in glass instead of plastic, forgoing plastic bottles and being careful about which restaurants we frequent.
BPA is a key component of shatterproof polycarbonate plastic items, including sports bottles and water jugs, and it’s found in the epoxy lining of canned foods and soda. The chemical migrates into foods (particularly acidic and/or salty foods) and mimics the hormone estrogen in the body, altering the ways these chemical messengers work.
The list of BPA’s suspected impacts is long and unsettling. It’s been implicated in obesity, diabetes, infertility and breast and prostate cancer, leading a number of states to enact legislation to rein in human exposure, particularly for infants and young children who are most vulnerable to developmental disruptions. In the European Union, BPA is classified as a reproductive toxicant.
DEHP is another endocrine disruptor produced in high volume and found in many consumer goods, including food packaging and food wrap films. It is commonly used as a softening agent in plastics made of polyvinyl chloride and because it is not chemically bonded to the plastic polymer, it, too, migrates out during routine use.
Effective 2009, the U.S. federal government banned the use of DEHP (and other phthalates) in children’s toys and child care products. Several states have passed similar restrictions to reduce exposure in youngsters based on research showing that DEHP can inhibit testosterone production and might disrupt the development of the male sexual tract and impair semen quality.
Ruthann Rudel, director of research at Silent Spring Institute, followed five families of four (two parents and two children each, aged 3-12 years) during a three-day dietary intervention designed to eliminate food-related sources of BPA and DEHP. Urine samples were measured for the presence of the chemicals before, during and right after the three-day intervention.
The families were all from the San Francisco area and were selected based on the likelihood that they were being exposed to BPA or DEHP by some combination of the following: consuming canned foods and sodas, drinking from personal water bottles or office coolers, microwaving foods in plastic and/or eating restaurant food.
Families maintained their usual eating habits for two days before and for three days after the intervention period. During the intervention, they ate a uniform menu from a caterer who prepared meals from fresh and organic fruits, vegetables, grains and meats without use of plastic utensils or non-stick cookware. Glass storage containers were used in which microwaving was allowed, but only after the plastic lid (non-BPA) had been removed. Coffee made with a French press or ceramic drip was allowed but not from a plastic coffee maker or from a café.
The Diet Connection
The dietary changes had a major impact on participants’ “body burden” of chemicals. During the intervention, urinary concentrations of BPA fell by about two-thirds and the metabolites of DEHP were reduced by more than half. The individuals who began with the highest levels of measurable BPA and DEHP saw the most dramatic drops.
As soon as families were free to resume their usual diets, BPA in the urine reverted back to nearly pre-intervention levels. The metabolites of DEHP also rose within a few days, but not as greatly. The takeaway is that food does appear to be a major source of exposure to BPA and DEHP, and by moving to a “fresh foods” diet, people can rapidly and measurably eliminate a good number of these chemicals in a matter of days. In the case of the families studied, researchers surmised that plastic food packaging and restaurant meals were the most likely dietary sources of the endocrine disruptors.
Perhaps the other take-home message is that the old adage “you are what you eat” still holds, but with an added chemical twist.