Abstract
Background
Chronic inflammation, associated with lifestyle and dietary factors, may contribute to colorectal carcinogenesis. To address this, we investigated associations of previously validated, inflammation biomarker panel-weighted, novel, 4-component lifestyle (LIS) and 19-component predominately whole foods-based dietary (DIS) inflammation scores with incident colorectal cancer (CRC) in the prospective Iowa Women’s Health Study (IWHS; 1986–2012; n = 34,254, of whom 1,632 developed CRC).
Methods
We applied the published scores’ components’ weights, summed the weighted components to constitute the scores (higher scores reflect a higher balance of pro-inflammatory exposures), and investigated LIS- and DIS-CRC associations using multivariable Cox proportional hazards regression.
Results
The multivariable-adjusted hazards ratios (HR) and their 95% confidence intervals (CI) for CRC among participants in the highest relative to the lowest LIS and DIS quintiles were 1.47 (1.26, 1.72; Ptrend < 0.01) and 1.07 (0.91, 1.25; Ptrend = 0.22), respectively. The corresponding findings for distal colon cancers were HR 1.78 (1.29, 2.47) and HR 1.34 (0.98, 1.84), respectively. Among those in the highest relative to the lowest joint LIS/DIS quintile, the HR for CRC was 1.60 (95% CI 1.30, 1.98).
Conclusions
Our results suggest that a more pro-inflammatory lifestyle, alone and jointly with a more pro-inflammatory diet, may be associated with higher CRC risk.
Disclosure Statement
None of the authors has a conflict of interest to disclose. The findings and conclusions contained within are those of the authors and do not necessarily reflect positions or policies of the National Cancer Institute or the Wilson P. and Anne W. Franklin Foundation. The National Cancer Institute and the Wilson P. and Anne W. Franklin Foundation had no influence on the analysis and interpretation of the data, the decision to submit the manuscript for publication, or the writing of the manuscript.
Funding
This work was supported by the US National Cancer Institute at the National Institutes of Health under Grant R01 CA039742 (support to DeAnn Lazovich), and the Anne and Wilson P. Franklin Foundation (support to Roberd M. Bostick).