Novel Dietary and Lifestyle Inflammation Scores Directly Associated with All-Cause, All-Cancer, and All-Cardiovascular Disease Mortality Risks Among Women

Background: Exogenous exposures collectively may contribute to chronic, low-grade inflammation and increase risks for major chronic diseases and mortality. We previously developed, validated, and reported a novel, FFQ-based and lifestyle questionnaire-based, inflammation biomarker panel-weighted, predominantly whole foods-based 19-component dietary inflammation score (DIS) and 4-component lifestyle inflammation score (LIS; comprising physical activity, alcohol intake, BMI, and current smoking status). Both scores were more strongly associated with circulating biomarkers of inflammation in 3 populations than were previously reported dietary inflammation indices. Associations of the DIS and LIS with mortality risk have not been reported.

Objectives: To investigate separate and joint associations of the DIS and LIS with all-cause, all-cancer, and cardiovascular disease (CVD) mortality risks in the prospective Iowa Women's Health Study (1986-2012; n = 33,155 women, ages 55-69 years, of whom 17,431 died during follow-up, including 4379 from cancer and 6574 from CVD).

Methods: We summed each study participant's scores' components, weighted by their published weights, to yield the participant's inflammation score; a higher score was considered more pro-inflammatory. We assessed DIS and LIS mortality associations using multivariable Cox proportional hazards regression.

Results: Among participants in the highest relative to the lowest DIS and LIS quintiles, the adjusted HRs for all-cause mortality were 1.11 (95% CI: 1.05-1.16) and 1.60 (95% CI: 1.53-1.68), respectively; for all-cancer mortality were 1.07 (95% CI: 0.97-1.17) and 1.51 (95% CI: 1.38-1.66), respectively; and for CVD mortality were 1.12 (95% CI: 1.03-1.21) and 1.79 (95% CI: 1.66-1.94), respectively (all Ptrend values < 0.01). Among those in the highest relative to the lowest joint LIS/DIS quintiles, the HRs for all-cause, all-cancer, and all-CVD mortality were 1.88 (95% CI: 1.71-2.08), 1.82 (95% CI: 1.50-2.20), and 1.92 (95% CI: 1.64-2.24), respectively.

Conclusions: More pro-inflammatory diets and lifestyles, separately but especially jointly, may be associated with higher all-cause, all-cancer, and all-CVD mortality risks among women.