Insulinemic and Inflammatory Dietary Patterns and Colorectal Cancer Risk: A Dietary Data Harmonization Study of One Million Participants in the COMETS Consortium.

Authors

Shi N, Hoobler R, Harewood R, Toland AE, Albanes D, Bouras E, Gunter MJ, Liao LM, Moore SC, Ricceri F, Rotter JI, Sinha R, Stolzenberg-Solomon R, Tjønneland A, Wood AC, Yu D, Playdon MC, Tabung FK

Affiliations

• Comprehensive Cancer Center, College of Medicine, The Ohio State University Wexner Medical Center, Columbus, OH, USA.
• Department of Nutrition and Integrative Physiology, University of Utah, Salt Lake City, UT, USA; Cancer Control and Population Sciences, Huntsman Cancer Institute, University of Utah, Salt Lake City, UT, USA.
• School of Public Health, Faculty of Medicine, Imperial College London, London, UK.
• Comprehensive Cancer Center, College of Medicine, The Ohio State University Wexner Medical Center, Columbus, OH, USA; Department of Internal Medicine, College of Medicine, The Ohio State University Wexner Medical Center, Columbus, OH, USA.
• Division of Cancer Epidemiology and Genetics, National Cancer Institute, Bethesda, MD, USA.
• Centre for Biostatistics, Epidemiology, and Public Health (C-BEPH), Department of Clinical and Biological Sciences, University of Turin, Italy.
• The Institute for Translational Genomics and Population Sciences, Department of Pediatrics, The Lundquist Institute for Biomedical Innovation at Harbor-UCLA Medical Center, Torrance, CA, USA.
• Danish Cancer Institute and Department of Public Health, University of Copenhagen, Copenhagen, Denmark.
• USDA/ARS Children's Nutrition Research Center, Baylor College of Medicine, Houston, TX, USA.
• Division of Epidemiology, Department of Medicine, Vanderbilt University Medical Center, Nashville, TN, USA.

Abstract

BACKGROUND: Inflammatory and insulinemic dietary patterns have been associated with colorectal cancer (CRC) risk, but generalizability across diverse populations with heterogeneous food supplies and dietary behaviors has not been established.

OBJECTIVE: We harmonized disparate dietary and covariate data on a large scale to compute the reverse Empirical Dietary Index for Hyperinsulinemia-rEDIH, reverse Empirical Dietary Inflammatory Pattern-rEDIP, and Healthy Eating Index (HEI)-2015 scores, and tested their associations with CRC risk.

METHODS: We leveraged data among 501,892 women and 407,390 men from six cohorts across the U.S. (NIH-AARP, MESA, PLCO, SCCS) and Europe (EPIC, ATBC) with varying sociodemographic characteristics, participating in the Consortium of Metabolomics Studies. We harmonized nomenclature and nutritional information for more than 800 unique food items across cohorts. We used multivariable-adjusted Cox regression, adjusting for demographic, clinical, and lifestyle factors, to calculate hazard ratios (HR) and 95% confidence intervals (95% CI) for the associations between the dietary indices and CRC risk per cohort, then meta-analyzed the estimates.

RESULTS: During a median follow-up of 14.9 years, 16,525 incident CRC cases were diagnosed. Participants in the highest quintile of rEDIH (low-insulinemic diet) had an 18% reduced risk of CRC (HR 0.82; 95% CI: 0.78, 0.86) compared to those in the lowest quintile. For the same comparison, similar risk reductions were observed for rEDIP (anti-inflammatory diet) (HR 0.84; 95% CI: 0.80, 0.89) and HEI-2015 (overall dietary quality) (HR 0.80; 95% CI: 0.76, 0.85). Heterogeneity between cohorts in the meta-analyzed estimates was low for rEDIH (I²=22.3%) compared to rEDIP (I²=62.5%) and HEI-2015 (I²=83.9%).

CONCLUSION: Using carefully harmonized data from nearly one million individuals in the U.S. and Europe, we observed significant CRC risk reduction with habitual intake of low-insulinemic and anti-inflammatory dietary patterns, comparable to higher overall dietary quality. Study findings underscore the utility of these dietary patterns for global cancer prevention efforts.