One of the main ways you can avoid the health hazards associated with exposure to bisphenol A (BPA) and phthalates that you can get from food and food containers is to choose fresh foods. The results of a recent study conducted by the nonprofit organization Breast Cancer Fund and the breast cancer research group Silent Spring Institute provide strong evidence to support this approach. What are BPA and phthalates and why is it so important to avoid exposure to them in our food?
What are BPA and phthalates?
The chemical BPA is a substance that is often used in the manufacture of polycarbonate plastics and epoxy resins found in canned food linings, plastic food containers, plastic bottles, toys, and water supply pipes. Because BPA is so ubiquitous in the environment, it is no surprise that the chemical was detected in the urine of 95 percent of participants in a study conducted by the Centers for Disease Control and Prevention. (Calafat 2005)
Phthalates are softening agents used in synthetic materials, including items that are used during food processing. Like BPH, phthalates are everywhere in the environment, so they can easily enter the food chain, beginning with the containers that collect the harvests in the fields to the devices used in the food production process.
Health hazards of BPA and phthalates
How dangerous is BPA? A 2010 study from the University of Texas School of Public Health reported that “BPA is associated with early sexual maturation, altered behavior, and effects on prostate and mammary glands” in rodents, and that in humans, the toxin “is associated with cardiovascular disease, diabetes, and male sexual dysfunction in exposed workers.” (Schecter 2010)
For example, in a study by British researchers that included 1,455 adults and published in the Journal of the American Medical Association, it was reported that individuals who had the highest levels of BPA were more likely to have heart disease, liver-enzyme abnormalities, and diabetes than people who has the lowest levels of the chemical in their blood. (Lang 2008)
A study conducted by researchers with Kaiser Permanente found that men who had elevated levels of BPA in their urine were more likely to experience worsening male sexual function, including erectile dysfunction and reduced libido, than men who had lower levels. (Li 2010)
BPA may also have an adverse effect on children. For example, one study found that females born to women who had been exposed to BPA early in pregnancy and who had high BPA concentrations in their urine may be more aggressive and hyperactive than the offspring of women with lower BPA levels. (Braun 2009) Numerous studies also have indicated that BPA can cause increased aggression, memory impairment, and hyperlocomotion in lab animals. A study published in March 2011 reported that “environment exposure to low dose of BPA may induce prostate to proliferate and aggravate testosterone-induced benign hyperplasia prostate in rats.” (Wu 2011)
Phthalates have been found to disrupt the synthesis of testosterone, and they also have been linked to abnormal development of male reproductive organs, which can result in infertility later in life. (Habert 2009) They also have been associated with symptoms of ADHD. (Kim 2010)
Fresh foods, BPA, and phthalates
The new BPA and phthalate study compared the levels of BPA and phthalates in 20 members of five families when they consumed their habitual diet with a period when they ate fresh foods. (Rudel 2010) The habitual diet included meals prepared outside the home, canned foods and sodas, frozen dinners, and foods microwaved in plastic containers.
For the fresh foods portion of the study, the families received catered meals consisting of almost exclusively fresh and organic produce, grains, meats, and snacks stored in glass and stainless steel containers. The families were supplied with stainless steel water bottles and lunch containers so they would avoid contact with common sources of BPA and phthalates. Food preparation avoided contact with plastic utensils and nonstick coated cookware. Study participants were encouraged to eat only the food provided by the study, but that if they did depart from the provided menu, they could choose fresh foods from glass jars and containers.
The study period lasted eight days: on days 1 and 2, the families consumed their regular diet; on days 3 through 5 they were provided with catered foods and special food containers; and on days 6 through 8 they returned to their regular diet. All the participants provided daily urine samples, and families completed food questionnaires for the entire study period.
Based on analysis of the urine samples, the researchers found that BPA levels declined by more than 60 percent, on average, in only three days. Levels of phthalates were reduced by half. After the family members returned to their regular eating habits, their BPA levels went back up. Phthalates levels did not rise as much, however, and the researchers this may be due to the fact that the chemical takes longer than BPA to accumulate in the body, or because the study participants changed their eating habits.
Given the participants’ reports about their habitual food practices, the researchers believe that use of canned foods and beverages and eating food from restaurants were the most likely sources of BPA exposure, because the families reported limited microwaving in plastic or using frozen dinners.
How to reduce BPA and phthalates in your diet
Here are some suggestions for how to reduce your exposure to BPA and phthalates:
- Choose fresh, organic fruits, vegetables, grains, and meats
- When fresh produce is not available, choose frozen rather than canned
- Eat out less often
- Buy soups and other prepared foods in cartons or glass rather than cans.
- Instead of soda, make your own beverages using herbal teas or fruit juices and store them in glass or stainless steel containers.
- Avoid using cups and bottles that contain BPA, which is found in hard transparent plastic made from polycarbonate. Look for a #7 or PC on the container.
- Store foods in glass and stainless steel containers rather than plastic.
- Use a stainless steel water bottle instead of a plastic one.
- Do not use plastic containers or wrap in the microwave.
- Make sure your dentist uses BPA-free filling materials and sealants.
Braun JM et al. Prenatal bisphenol A exposure and early childhood behavior. Environ Health Perspect 2009 Dec; 117(12): 1945-52
Calafat AM et al. Urinary concentrations of bisphenol A and 4-nonylphenol in a human reference population. Environ Health Perspect 2005 Apr; 113(4): 391-95
Habert R et al. Adverse effects of endocrine disruptors on the foetal testis development: focus on the phthalates. Folia Histochem Cytobiol 2009; 47(5): S67-74
Kim BN et al. Phthalates exposure and attention-deficit/hyperactivity disorder in school-age children. Biol Psychiatry 2009 Nov 15; 66(10): 958-63
Lang IA et al. Association of urinary bisphenol A concentration with medical disorders and laboratory abnormalities in adults. JAMA 2008 Sep 17; 300(11): 1303-10
Li DK et al. Relationship between urine bisphenol-A level and declining male sexual function. J Andrology 2010 Sep-Oct; 31(5): 500-6
Rudel RA et al. Food packaging and bisphenol A and Bis(2-ethylhexyl) phthalate exposure: findings from a dietary intervention. Environ Health Perspect 2011 Jul; 119(7):914-20
Schecter A et al. Bisphenol A (BPA) in US food. Environ Sci Technol 2010 Dec 15; 44(24): 9425-30
Wu JH et al. Oral exposure to low-dose bisphenol A aggravates testosterone-induced benign hyperplasia prostate in rats. Toxicol Ind Health 2011 Oct; 27(9):810-19