The Dietary Inflammatory Index Is Associated with Prostate Cancer Risk in French Middle-Aged Adults in a Prospective Study

Abstract

Background: Chronic inflammation is one of the mechanisms involved in carcinogenesis. Diet is a major source of pro- and anti-inflammatory compounds. The Dietary Inflammatory Index (DII) was designed to estimate its overall inflammatory potential.

Objective: Our objective was to investigate the associations between the DII and overall, breast, and prostate cancer risks.

Methods: This prospective study included 6542 participants [3771 women and 2771 men with a mean ± SD age of 49.2 ± 6.4 y and a BMI (in kg/m2) of 24.0 ± 3.6 at baseline] from the Supplémentation en VItamines et Minéraux AntioXydants (SU.VI.MAX) cohort who completed at least six 24-h dietary records during the first 2 y of follow-up. The DII was based on 36 food variables. Higher scores corresponded to more proinflammatory diets. A total of 559 incident cancers were diagnosed (median follow-up, 12.6 y), including 158 female breast and 123 prostate cancers (the 2 main cancer sites in this cohort). Associations were characterized by multivariable Cox proportional hazards models. Stratified analyses were performed according to the median of usual daily alcohol intake.

Results: Sex-specific quartiles of the DII were positively associated with prostate cancer risk [quartile (Q) 4 compared with Q1, HR: 2.08; 95% CI: 1.06, 4.09] but not with overall or breast cancer risks. There was an interaction between the DII and alcohol intake (grams per day) on overall cancer risk (P-interaction = 0.02): the DII was positively associated with overall cancer risk in low-to-moderate alcohol drinkers (Q4 compared with Q1 HR: 1.75; 95% CI: 1.15, 2.68; P-trend = 0.02), whereas no association was detected in higher consumers of alcohol (P-trend = 0.8). This interaction was also observed for breast cancer (P-interaction = 0.001).

Conclusion: Consistent with mechanistic data, findings from this study indicated that proinflammatory diets are associated with increased prostate cancer risk and, in low-to-moderate alcohol drinkers, with increased overall and breast cancer risk. The SU.VI.MAX trial was registered at clinicaltrials.gov as NCT00272428.

Keywords: Dietary Inflammatory Index; cancer; diet; inflammation; prospective study.

Conflict of interest statement

Author disclosures: JR Hébert owns controlling interest in Connecting Health Innovations, a company planning to license the right to his invention of the Dietary Inflammatory Index from the University of South Carolina in order to develop computer and smart phone applications for patient counseling and dietary interventions in clinical settings. N Shivappa and MD Wirth are employees of Connecting Health Innovations. L Graffouillère, M Deschasaux, F Mariotti, L Neufcourt, P Latino-Martel, S Hercberg, P Galan, C Julia, E Kesse-Guyot, and M Touvier, no conflicts of interest. The funders had no role in the design, analysis or writing of this article.

© 2016 American Society for Nutrition.