Abstract
OBJECTIVE: To examine the association between consumption of fruits and vegetables and pesticide residue intake from consumption of fruits and vegetables and risk of ultrasound- or hysterectomy-confirmed fibroids. Only a few studies have evaluated the association of fruit and vegetable intake with uterine fibroids, with inconsistent results. No studies have examined pesticide exposure through fruits and vegetables with fibroid risk. DESIGN: Prospective cohort study. Cox proportional hazards models were used to calculate hazard ratios (HRs) and 95% confidence intervals (CIs). SETTING: Not applicable. PATIENT(S): A total of 81,782 premenopausal participants from the Nurses' Health Study II cohort were followed from 1991 to 2009 for fruit and vegetable analysis, and 49,927 participants were followed from 1999 to 2009 for pesticide residue burden analysis. Their diet was assessed every 4 years with a food frequency questionnaire. Fruits and vegetables were classified into high- or low-pesticide residues using a validated method based on surveillance data from the US Department of Agriculture. INTERVENTION(S): Not applicable. MAIN OUTCOME MEASURE(S): Cases of ultrasound- or hysterectomy-confirmed fibroids were identified from self-reports to validated questionnaires. RESULT(S): From 1991 to 2009, 9,706 incident cases of ultrasound- or hysterectomy-confirmed fibroids were reported, and 4,195 incident cases were identified from 1999 to 2009. No association was observed between total fruit and vegetable consumption and uterine fibroid risk. Participants with the highest intake of total fruits (≥4/day) were 10% less likely to develop uterine fibroids compared with participants who consumed <1/day (95% CI = 0.80-1.01). No associations were observed with any other fruit or vegetable groups. An inverse association was observed between intake of high-pesticide-residue fruits and vegetables and fibroid risk (HR for 5(th) vs. 1(st) quintile = 0.87; 95% CI = 0.77-0.99), while no association with low-pesticide-residue fruits and vegetables was observed (HR for 5(th) vs. 1(st) quintile = 1.08; 95% CI = 0.95-1.23). CONCLUSION(S): Our findings suggest that pesticide residues on fruits and vegetables are not associated with a higher risk of uterine fibroids. Furthermore, our results suggest that intake of fruits may be associated with a lower risk of fibroids. Future research in this area should focus on dietary exposures across the life course as well as assessment of class-specific pesticides.