BACKGROUND: Previously, we reported on associations between dietary patterns and incident acute coronary heart disease (CHD) in the REGARDS (Reasons for Geographic and Racial Differences in Stroke) study. Here, we investigated the associations of dietary patterns and a dietary index with recurrent CHD events and all-cause mortality in REGARDS participants with existing CHD.
METHODS AND RESULTS: We included data from 3562 participants with existing CHD in REGARDS. We used Cox proportional hazards regression to examine the hazard of first recurrence of CHD events-definite or probable MI or acute CHD death-and all-cause mortality associated with quartiles of empirically derived dietary patterns (convenience, plant-based, sweets, Southern, and alcohol and salads) and the Mediterranean diet score. Over a median 7.1 years (interquartile range, 4.4, 8.9 years) follow-up, there were 581 recurrent CHD events and 1098 deaths. In multivariable-adjusted models, the Mediterranean diet score was inversely associated with the hazard of recurrent CHD events (hazard ratio for highest score versus lowest score, 0.78; 95% confidence interval, 0.62-0.98; PTrend=0.036). The Southern dietary pattern was adversely associated with the hazard of all-cause mortality (hazard ratio for Q4 versus Q1, 1.57; 95% confidence interval, 1.28-1.91; PTrend<0.001). The Mediterranean diet score was inversely associated with the hazard of all-cause mortality (hazard ratio for highest score versus lowest score, 0.80; 95% confidence interval, 0.67-0.95; PTrend=0.014).
CONCLUSIONS: The Southern dietary pattern was associated with a greater hazard of all-cause mortality in REGARDS participants. Greater adherence to the Mediterranean diet was associated with both a lower hazard of recurrent CHD events and all-cause mortality.
Alzheimer's disease (AD) risk increases with age and lacks efficacious pharmacological options. Summaries of the existing evidence reveal an association between Mediterranean-style diet adherence and reduced AD incidence; however, no review has investigated this relationship with respect to the hallmark AD biomarkers (tau and beta-amyloid) that manifest decades before clinical symptomatology. MEDLINE, PubMed, PsycINFO, Google Scholar, and SCOPUS databases were systematically searched to identify peer-reviewed articles investigating diet and AD biomarkers in the last 2 decades.
Two thousand seven hundred twenty-six records were extracted, quality assessed, and double-blind screened by 2 authors. Fifteen studies met the inclusion criteria and 13 studies found a significant relationship. Of these, 4 studies found a high-glycemic load was related to an increase in AD biomarker burden; 6 found adherence to a Mediterranean or "AD-protective" dietary pattern conferred a reduction in AD biomarker burden. Meta-analysis revealed a small but significant effect of diet on AD biomarkers (β = 0.11 [95% CI 0.04-0.17], p = 0.002). This systematic review supports the notion that diet and nutrition display potential for nonpharmacological AD prevention.