Higher Diet Quality Is Inversely Associated with Mortality in African-American Women

Background: Diet quality has been inversely associated with overall mortality in white populations, but the evidence in African-American populations is limited. Objective: The goal of the present study was to assess diet quality in relation to all-cause mortality in the Black Women's Health Study, a follow-up study of African-American women begun in 1995. Methods: Data used in this study were obtained via biennial questionnaires from 1995 to 2011. Based on food-frequency questionnaire data collected in 1995 and 2001, we calculated an index-based diet quality score [Dietary Approaches to Stop Hypertension (DASH)] and derived dietary patterns (prudent and Western) with the use of factor analysis. We followed 37,001 women who were aged 30-69 y and free of cancer, cardiovascular disease, and diabetes at baseline for mortality through 2011. Multivariable Cox regression was used to estimate HRs and 95% CIs. Analyses were conducted in 2014. Results: Based on a total of 1678 deaths during 16 y of follow-up, higher DASH scores were associated with reduced all-cause mortality (HR: 0.75; 95% CI: 0.63, 0.89 for highest vs. lowest quintiles). The DASH components most strongly associated with lower mortality were high intake of whole grains and low intake of red and processed meat. A Western dietary pattern, characterized by high intake of red and processed meat, was associated with increased all-cause mortality rates (HR: 1.37; 95% CI: 1.17, 1.60 for highest vs. lowest quintiles of score); a prudent dietary pattern was not associated with risk. Conclusion: A DASH-style diet high in intake of whole grains and low in consumption of red meat is associated with reduced mortality rates in healthy African-American women.