Abstract
OBJECTIVE: To examine the association between the intake of fruits and vegetables with high- vs. low-pesticide residue burden and diagnosis of laparoscopically confirmed endometriosis. The etiology of endometriosis is not well understood, but dietary factors may influence the risk. Pesticides may act as endocrine disruptors, and the intake of pesticide-contaminated food is a common exposure pathway. DESIGN: Prospective cohort study. Hazard ratios and 95% confidence intervals were calculated using multivariable Cox proportional hazard models to evaluate the intake of fruits and vegetables with high- and low-pesticide residues in relation to the diagnosis of laparoscopically confirmed endometriosis. SETTING: Not applicable. PATIENT(S): Premenopausal US women (N = 52,053) of the Nurses' Health Study II, aged 34-53 years at study baseline (1999), were followed until 2013. The diet was assessed every 4 years using a validated food frequency questionnaire. A previously developed and validated pesticide residue burden score (PRBS), on the basis of the US Department of Agriculture Pesticide Data Program, was used to assign fruits and vegetables to pesticide residue groups (high/low). INTERVENTION(S): Not applicable. MAIN OUTCOME MEASURE(S): Cases of laparoscopically confirmed endometriosis were identified from self-reports to validated questionnaires. RESULT(S): During 14 years of follow-up, 956 incidences of laparoscopically confirmed endometriosis were reported. No association was observed between the intake of high- or low-PRBS fruit and vegetable intake and endometriosis (hazard ratio for 5th vs. 1st quintile: high-PRBS intake = 0.94, 95% confidence interval = 0.73-1.23; low-PRBS intake = 1.07, 95% confidence interval = 0.82-1.40). No associations were observed for high- or low-PRBS fruit and vegetable intake by fertility status. CONCLUSION(S): No clear associations were observed between high- or low-PRBS fruit and vegetable intake and endometriosis risk among premenopausal women. To our knowledge, this is the first study to evaluate the association between dietary pesticide residue intake and endometriosis. Further research is needed, particularly to evaluate this association among a younger population of women (adolescence or early adulthood) and assess the dietary exposure to specific pesticides or chemical families.