Dietary inflammatory index and risk of epithelial ovarian cancer in African American women

Chronic inflammation has been implicated in the development of epithelial ovarian cancer (EOC); yet the contribution of inflammatory foods and nutrients to EOC risk has been understudied. We investigated the association between the dietary inflammatory index (DII), a novel literature-derived tool to assess the inflammatory potential of one's diet, and EOC risk in African American (AA) women in the African American Cancer Epidemiology Study, the largest population-based case–control study of EOC in AA women to date. The energy-adjusted DII (E-DII) was computed per 1,000 kilocalories from dietary intake data collected through a food frequency questionnaire, which measured usual dietary intake in the year prior to diagnosis for cases or interview for controls. Adjusted odds ratios (OR) and 95% confidence intervals (CI) were estimated using multivariable logistic regression for the association between the E-DII and EOC risk. 493 cases and 662 controls were included in the analyses. We observed a 10% increase in EOC risk per a one-unit change in the E-DII (OR = 1.10, 95% CI = 1.03–1.17). Similarly, women consuming the most pro-inflammatory diet had a statistically significant increased EOC risk in comparison to the most anti-inflammatory diet (ORQuartile4/Quartile1 = 1.72; 95% CI = 1.18–2.51). We also observed effect modification by age (p < 0.05), where a strong, significant association between the E-DII and EOC risk was observed among women older than 60 years, but no association was observed in women aged 60 years or younger. Our findings suggest that a more pro-inflammatory diet was associated with an increased EOC risk, especially among women older than 60 years.