James Hebert

ScD

Arnold School of Public Health University of South Carolina

Distinguished Professor, Director of South Carolina Statewide Cancer Prevention & Control Program

PLCO (Learn more about this study)

PLCO-76

Apr 11, 2014

The Influence of the Dietary Inflammatory Index (DII) on Cancer Risk

An estimated 1,665,540 new cancer cases and 585,720 cancer deaths are projected to occur in the United States in 2014. Both experimental and observational studies provide evidence that chronic inflammation plays a crucial role in carcinogenesis. Evidence also shows that diet modulates inflammation, and significantly predicts concentrations of inflammatory biomarkers such as high-sensitivity C-reactive protein (hs-CRP), interleukin-6 (IL-6) and tumor necrosis factor alpha receptor 2. Given the evidence that dietary factors can influence inflammatory processes, and the idea that no nutrient is consumed alone but in conjunction with other nutrients and non-nutrient components of food, we previously developed and validated a dietary inflammatory index (DII) to assess the overall quality of diet with regard to its inflammation potential. Briefly, an extensive literature search was performed to obtain peer-reviewed journal articles that examined the association between six inflammatory biomarkers (IL-1, IL-4, IL-6, IL-10, TNFα, and CRP) and 45 specific foods and nutrients (components of the DII). Scores were derived and standardized to a representative global diet database constructed based on 11 datasets from diverse populations in different parts of the world. Overall DII scores for each individual represent the sum of each of the DII components in relation to the comparison database. The DII score characterizes an individual’s diet on a continuum from maximally anti-inflammatory to maximally pro-inflammatory, with a higher DII score indicating a more pro-inflammatory diet and a lower DII score indicating a more anti-inflammatory diet.
Previously we have conducted a number of DII construct validation studies using data from the Women’s Health Initiative (WHI) and Buffalo Cardio-Metabolic Occupational Police Stress (BCOPS) study and found that the DII significantly predicted concentrations of serum hs-CRP, IL-6, TNFα, as well as the glucose intolerance component of the metabolic syndrome. In other studies (e.g., WHI), the DII has been shown also to significantly predict risk of colorectal cancer. The WHI is a large cohort study comprised entirely of older women, while the BCOPS design was cross-sectional.
Given these previous studies, our current objective is to evaluate the association of the DII with risk of total cancer and site-specific cancers in the Prostate, Lung, Colorectal and Ovarian Cancer Screening Trial (PLCO). The PLCO is a well characterized and diverse study population with large number of cancer cases that would provide ample power to conduct subgroup analysis by gender and race.

1) To assess the inflammatory potential of usual diets of PLCO participants and compare with NHANES levels in a descriptive study

2) To evaluate the association of the inflammatory potential of diet and risk of total cancer

3) To evaluate the association of the inflammatory potential of diet and risk of site-specific cancers including colorectal, lung, prostate, breast, liver, pancreatic, and ovarian cancers

Azza Shoaibi
Arnold School of Public Health, University of South Carolina/ Cancer Prevention and Control Program

Nitin Shivappa
Arnold School of Public Health, University of South Carolina/Cancer Prevention and Control Program

Fred Tabung
Arnold School of Public Health, University of South Carolina/Cancer Prevention and Control Program

Michael Wirth
Arnold School of Public Health, University of South Carolina/Cancer Prevention and Control Program