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

Abstract

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 (AACES), 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.

Association of Dietary Inflammatory Potential With Colorectal Cancer Risk in Men and Women

“…Given that the nutrient-based index scores are influenced by nutritional supplements use, 28,29 findings from these previous studies that are directly comparable to the current study results are from studies that calculated the nutrient-based index scores from food sources only (i.e., without including supplements). In a study conducted using data from the Iowa Women’s Health Study, there was a statistically significant 20% higher risk of colorectal cancer (HR: 1.20; 95% CI: 1.01–1.43) that became nonsignificant when supplements were excluded (HR: 1.12; 95% CI: 0.90–1.38).…”

Meta‐analysis of the association between dietary inflammatory index (DII) and cancer outcomes

“…Twenty‐four articles were reviewed for full text . The summary statistics for each of these are presented in Table .…”

“…The summary statistics for each of these are presented in Table . Of those, 9 examined cancer incidence, 2 examined cancer mortality, and 13 examined odds of cancer in case–control studies . Additionally, 3 articles were published in 2014, 9 articles were published in 2015, and 12 were published in 2016 .…”

Dietary Patterns and Colorectal Cancer Risk: a Review of 17 Years of Evidence (2000–2016)

“…Nutritional supplements influence DII scores given that the index is comprised mostly of nutrients; therefore, the source of dietary data for DII calculation (food sources and/or nutritional supplements) is important. Seven studies (four cohort [44–46, 52] and three case-control [42, 47, 48]) examined the association of the DII with colorectal cancer risk during the period covered by this review. Overall, results were consistent that higher (more pro-inflammatory) DII scores were associated with higher risk of colorectal cancer; although there were differences based on whether the DII was calculated from food sources or from a combination of food and supplements.…”

“…Studies that have derived separate DII scores with and without inclusion of supplements have found positive associations for DII scores with supplements and no association for DII scores from diet-only sources [46, 52]. For example, in the Iowa Women’s Health Study, Shivappa et al found a 20% higher risk of colorectal cancer (HR: 1.20; 95%CI: 1.01, 1.43) that became nonsignificant with the exclusion of supplements (HR: 1.12; 95%CI: 0.90, 1.38) [46].…”