The association between dietary intake and cervical intraepithelial neoplasia grade 2 or higher among women in a high-risk rural area of china

Objective To evaluate the relationship between dietary intake and risk of cervical intraepithelial neoplasia grade 2 or higher (CIN2+) while controlling for human papillomavirus (HPV) infection. Methods In 1999 and 2002, 11,031 women aged 35–50, were screened as part of two cross-sectional population-based cervical cancer screening studies in China. Dietary food intake information was collected by a 79-item Food Frequency Questionnaire (FFQ). 748 HPV-positive women (557 normal biopsy; 95 CIN2, 79 CIN3 and 17 cancer) with completed interviews and biopsy results were included in our data analysis. Specific dietary food groups were classified into dark-colored vegetables, light-colored vegetables, onion vegetables, legumes, nuts, eggs, and meat. Unconditional logistic regression was used to evaluate the association between dietary intake and the risk of developing CIN2+. Results Inverse associations between CIN2+ risk and onion vegetables, legumes, nuts, and meat were observed. Comparison of the lowest and highest tertiles for consumption of onion vegetables, legumes, nuts, and meat yielded adjusted odds ratios (ORs) of 0.589 [95% confidence intervals (CI), 0.387–0.897; P for trend = 0.011], 0.591 (95% CI, 0.392–0.892; P for trend = 0.012), 0.635 (95% CI, 0.426–0.946; P for trend = 0.019), 0.624 (95% CI, 0.406–0.958; P for trend = 0.044), respectively, for CIN2+ risk among 748 HPV-positive women. No associations were found between CIN2+ risk and dark-colored vegetables, light-colored vegetables or eggs. Conclusions Dietary intake of onion vegetables, legumes, nuts, and meat is associated with reduced risk of CIN2+. These foods may provide a protective factor against CIN2+.