Epidemiological studies evaluating the association of nut with risk of coronary artery disease (CAD) have produced inconsistent results. We conducted a meta-analysis to summarize the evidence from prospective cohort studies regarding the association between nut consumption and risk of CAD.
Pertinent studies were identified by searching Web of Knowledge, Pubmed and Wan Fang Med Online up to January 2014. Random-effect model was used to combine the results. Dose-response relationship was assessed by restricted cubic spline. Publication bias was estimated using Begg' funnel plot and Egger's regression asymmetry test.
Nine articles with 13 prospective studies involving 6,127 CAD cases and 347,477 participants were included in this meta-analysis. Pooled results suggested that highest nut consumption amount versus lowest amount was significantly associated with the risk of CAD [summary relative risk (RR)=0.660, 95%CI=0.581-0.748, I(2)=39.6%]. Linear dose-response relationship was found between nut consumption and CAD risk, and the risk of CAD decreased by 5% for every 1 serving/week increase intake of nut. A protective effect for CAD was found when consumed more than 2 servings/week of nut. The RR of CAD was 0.96 (0.89-1.02), 0.91 (0.82-0.99), 0.85 (0.77-0.95), 0.80 (0.72-0.89), 0.75 (0.65- 0.85) and 0.70 (0.58-0.83) for 1, 2, 3, 4, 5 and 6 servings/week of nut consumption, respectively.
Our analysis indicated that nut consumption has a protective effect on CAD.