Nineteen-Year Associations Between Three Diet Quality Indices and All-Cause And Cardiovascular Disease Mortality: The Australian Diabetes, Obesity And Lifestyle Study.

Background Examining a variety of diet quality methodologies will inform best practice use of diet quality indices for assessing all-cause and CVD mortality. Objective To examine the association between three diet quality indices (Australian Dietary Guideline Index, DGI; Dietary Inflammatory Index, DII; Mediterranean-DASH Intervention for Neurodegenerative Delay, MIND) and risk of all-cause mortality, CVD mortality and non-fatal CVD events up to 19 years later. Design Data on 10,009 adults (51.8 years; 52% female) from the Australian Diabetes, Obesity and Lifestyle study were used. A food frequency questionnaire was used to calculate DGI, DII and MIND at baseline. Cox proportional hazard models were used to estimate hazard ratios (HR) and 95% CI of all-cause mortality, CVD mortality and non-fatal CVD events (stroke; myocardial infarction) according to 1 SD increase in diet quality, adjusted for age, sex, education, smoking, physical activity, energy intake, history of stroke or heart attack, and diabetes and hypertension status. Results Deaths due to all-cause (n = 1,955) and CVD (n = 520), and non-fatal CVD events (n = 264) were identified during mean follow-ups of 17.7, 17.4 and 9.6 years, respectively. For all-cause mortality, HRs associated with higher DGI, DII and MIND were 0.94 (95% CI: 0.89, 0.99), 1.08 (95% CI: 1.02, 1.15) and 0.93 (95% CI: 0.89, 0.98), respectively. For CVD mortality, HRs associated with higher DGI, DII and MIND were 0.93 (95% CI: 0.85, 0.99), 1.10 (95% CI: 1.00, 1.24) and 0.90 (95% CI: 0.82, 0.98), respectively. There was limited evidence of associations between diet quality and non-fatal CVD events. Conclusions Better quality diet predicted lower risk of all-cause and CVD mortality in Australian adults, while a more inflammatory diet predicted higher mortality risk. These findings highlight the applicability of following Australian dietary guidelines, a Mediterranean style diet and a low-inflammatory diet for the reduction of all-cause and CVD mortality risk.