Dietary Correlates of Urinary Phthalate Metabolite Concentrations in 6-19 Year Old Children and Adolescents from NHANES

Abstract

BACKGROUND AND AIM: Children are particularly vulnerable to phthalates, and food is one source of exposure. However, a comprehensive analysis that investigates exposure from food type and source has yet to be undertaken. We use reduced rank regression, a dimension reduction method, to identify dietary patterns associated with urinary phthalate metabolite concentrations in children in a large, US study with detailed data on dietary intake. METHODS: We used data from 2,402 participants 6-19 years old from the 2005-2010 National Health and Nutrition Examination Survey who had urinary phthalate metabolites measured by mass spectrometry. Participants recalled their diet during the 24 hours before urine collection. We quantified dietary intake and source (i.e., home-prepared vs. prepared away from the home) of 135 food groups. We used reduced rank regression to identify dietary patterns explaining variation in overall urinary concentrations of ∑di-2-ethylhexyl phthalate (DEHP) and seven phthalate metabolites, adjusting for urinary creatinine and sociodemographics. We also examined pairwise associations between food groups and phthalate concentrations. RESULTS:We identified eight dietary patterns that cumulatively explained 11.2% of variation in phthalates. The most variation was explained by a diet high in breakfast foods prepared away from home (e.g., bacon, low-sugar cereal, and reduced-fat milk). A one SD increment in adherence to the breakfast food dietary pattern was associated with an 11.3% higher monocarboxy-isononyl phthalate concentration (95% CI: 6.5, 15.9) and a 7.4% higher monobutyl phthalate concentration (95% CI: 3.0, 12.1). We observed some weak pairwise associations between food group intake and urinary phthalates (e.g., 0.1% [95% CI: 0.0, 0.2] higher DEHP per SD increment in milk intake). CONCLUSIONS:We identified dietary factors that may be sources of phthalate exposure or reflect lifestyle correlates. Diet and preparation location explained a small percent variation in phthalate concentrations, suggesting the need for more detailed information on food processing and packaging. KEYWORDS: food/nutrition, phthalates, children's environmental health, biomarkers of exposure