Introduction: Exposure to phthalates has been associated to metabolic abnormalities and cardiovascular risk. Commonly used plastic food wrappers may contain up to 40% of phthalates and could be an important source of exposure to these chemicals especially when heated.
Hypothesis: Use of plastic food wrappers high in phthalates affects metabolic homeostasis.
Methods: We assessed the cross-sectional relation of plastic food wrappers use and metabolic syndrome in 188 women from the Mexican Teachers’ Cohort. We evaluated self-reported frequency of use of food wrappers based on 3 questions and categorized participants in tertiles. Fasting blood samples and anthropometry were obtained in a clinical visit to determine metabolic syndrome status. Continuous variables were log-transformed. We used multivariable logistic and linear regression models to estimate odds ratios, mean % change and 95% confidence intervals (CI) for metabolic syndrome and its components using the lowest tertile of exposure as the reference.
Results: Mean (±SD) frequency use of total plastic food wrapper was 1.52± 3 times/week and the prevalence of metabolic syndrome was 34%. Use of total plastic food wrappers was associated with metabolic syndrome even after adjusting for diet and other important confounders. The multivariable-adjusted odds ratio (OR) comparing extreme tertiles was 2.61 (95% CI: 1.03, 6.61; ptrend = 0.10). The association appeared to be driven by use of plastic food wrappers that were heated in a microwave oven. We did not observe an independent association with metabolic syndrome components.
Conclusions: In this cross-sectional study use of plastic food wrappers, especially when heated in the microwave oven, was associated with the presence of metabolic syndrome. These associations did not appear to be driven by a particular metabolic syndrome component. Longitudinal studies are warranted to confirm this association, ideally with measures of urinary phthalate metabolites to confirm its mediation in the association.