Dr. Sheela Sathyanarayana, a pediatric environmental health specialist whose research focuses on endocrine-disrupting chemicals, addresses questions about phthalates. Earlier this year, she and her colleagues published a review of food monitoring and epidemiology data on phthalates.
Thank you to Dr. Wendy Sue Swanson, a pediatrician at The Everett Clinic in Mill Creek, a member of Children’s medical staff and author of the Seattle Mama Doc blog, for submitting these questions.
Q. We’re hearing more and more about phthalates every year. Are there more phthalates in infants’ and children’s diets now or is there just more awareness?
A. What has changed is that we used to think that plastic was the main source of phthalates, but more recent research shows that food is actually the main source, often due to contamination from food processing. Processed foods, high-fat dairy, meats and canned foods are particularly high in phthalates.
Parents may be concerned about phthalates in plastic. However, this is only one route of exposure, and chemicals are most likely to leach out of plastic into food if containers are heated with food inside.
Q. What human data shows that phthalates cause endocrine disruption?
A. There are many studies in humans, often focusing on changes in hormone concentrations. Research often examines reproductive health outcomes because changes related to reproductive hormones can affect reproductive endpoints.
- Prenatal exposure was associated with a decreased anogenital distance (marker of androgenization).1
- Exposure through breast milk has been associated with increased luteinizing hormone (LH), decreased free testosterone and increased serum human binding globulin in 3-month-old male infants.2
- In adult males, concurrent exposure may increase the risk for abnormal sperm morphology or sperm DNA damage.3
Q. What other health effects are associated with phthalates?
In a recent review of the literature, “Phthalate Exposure and Children’s Health,” we found that:
- Early childhood exposure may increase the risk of increased rhinitis, eczema, asthma and wheezing4
- Prenatal exposure may increase the risk of alterations in infant/toddler physical development as well as increased externalizing (hyperactivity and aggression) and autistic-like child behavior5
Q. With regard to diet recommendations, the review on food monitoring and epidemiological data mentioned avoiding high-fat dairy products. Do you recommend children drink 2% milk starting at age 1?
A. I absolutely recommend 2% milk. Recently, Women, Infants and Children changed their guidelines from whole milk to 2% milk. Up to age 1, breast milk and whole milk are great.
When we said to avoid high-fat dairy products, we were referring mainly to cream and butter. The review found that poultry, cream and fats are routinely contaminated with higher concentrations of di-2-ethylhexyl phthalate (DEHP) than other foods. Low-fat milk, yogurt, eggs, fresh fruits and vegetables, rice, beverages and water were found to contain low concentrations of phthalates overall.
Q. With regard to personal care products, can you explain why phthalates are in them? What pearls shall we share with families about reducing use?
A. Phthalates function as a plasticizer, making lotion greasier. In cosmetics, they serve as a color stabilizer. Any personal care product with a fragrance tends to have more phthalates because they are a component of many fragrances.
A study seven years ago found higher concentration of phthalates in infants who had increased personal care product use.6 A lot of personal care products are using less phthalates now, but I always recommend minimizing the use of these products. I tell families that newborn babies don’t need any products because they have perfect skin.
Q. If families could make a couple of easy changes, what would you recommend?
A. I would recommend eating fresh foods at home and not processed foods. Even baby foods that are marketed as organic can be processed.
My second recommendation would be to take shoes off at home, keep dust under control and vacuum as much as possible because phthalates in dust are associated with allergies and asthma.
There are a couple of helpful handouts on phthalates and bisphenol A (BPA) for families and healthcare providers on the Northwest Pediatric Environmental Health Specialty Unit factsheet webpage.
- Swan SH, Main KM, Liu F, et al. Decrease in anogenital distance among male infants with prenatal phthalate exposure. Environ Health Perspect. 2005 Aug;113(8):1056-61.
- Main KM, Mortensen GK, Kaleva MM, et al. Human breast milk contamination with phthalates and alterations of endogenous reproductive hormones in infants three months of age. Environ Health Perspect. 2006 Feb;114(2):270-6.
- Hauser R, Meeker JD, Duty S, Silva MJ, Calafat AM. Altered semen quality in relation to urinary concentrations of phthalate monoester and oxidative metabolites. Epidemiology. 2006 Nov;17(6):682‐91.
- Bornehag CG, Sundell J, Weschler CJ, et al. The association between asthma and allergic symptoms in children and phthalates in house dust: a nested case-control study. Environ Health Perspect. 2004 Oct;112(14):1393‐7.
- Engel SM, Miodovnik A, Canfield RL, et al. Prenatal phthalate exposure is associated with childhood behavior and executive functioning. Environ Health Perspect. 2010 Apr;118(4):565‐71.
- Sathyanarayana S, Karr CJ, Lozano P, et al. Baby care products: possible sources of infant phthalate exposure. Pediatrics. 2008 Feb;121(2):e260-e268.