The Dietary Inflammatory Index Is Associated with Colorectal Cancer Risk in the Multiethnic Cohort

Area of Science:

• Nutrition Science
• Cancer Epidemiology
• Public Health

Background:

• Systemic inflammation, influenced by diet, is a known risk factor for colorectal cancer (CRC).
• Limited research exists on the association between dietary inflammatory potential and CRC incidence in diverse ethnic groups.

Purpose of the Study:

• To investigate the relationship between dietary inflammatory potential, using the Dietary Inflammatory Index (DII), and CRC incidence across various racial/ethnic groups.
• To test the hypothesis that proinflammatory diets increase CRC risk and that this association may vary by race/ethnicity.

Main Methods:

• Prospective cohort study (Multiethnic Cohort - MEC) with 190,963 participants followed for 20 years.
• Dietary inflammatory potential assessed using energy-adjusted Dietary Inflammatory Index (E-DII) scores derived from food frequency questionnaires.
• CRC incidence determined via cancer registry linkage; Cox proportional hazards regression used for analysis, adjusting for CRC risk factors.

Main Results:

• Higher E-DII scores (more proinflammatory diets) were associated with increased CRC risk overall (HR: 1.21).
• Associations varied by sex and race/ethnicity, with significant associations observed in white, Japanese-American, and Latino men, and native Hawaiian women.

Conclusions:

• Diets with high proinflammatory potential, as indicated by the E-DII, are associated with an elevated risk of CRC.
• These findings underscore the role of dietary patterns in CRC risk across diverse racial and ethnic populations.