Monounsaturated Fatty Acid Intake and Stroke Risk: A Meta-analysis of Prospective Cohort Studies

Background We performed a meta-analysis aiming to clarify the relationship between monounsaturated fatty acid (MUFA) intake and stroke risk. Methods Relevant studies were identified by searching relevant databases through January 2016. We included cohort studies that reported relative risks (RRs) with 95% confidence intervals (CIs) for the association between MUFA intake and stroke risk. A random-effects model was used to derive composite RR estimates for stroke. Results Ten prospective cohort studies including 314,511 nonoverlapping individuals and 5827 strokes were included. Higher MUFA intake was not associated with risk of overall stroke (RR = .86 [95% CI, .74-1.00]) and risk of ischemic stroke (RR = .92 [95% CI, .79-1.08]), but was associated with a reduced risk of hemorrhagic stroke (RR = .68 [95% CI, .49-.96]). In subgroup analyses, higher MUFA intake was associated with a reduced risk of stroke for a follow-up duration of 14 years or more (RR = .77 [95% CI, .68-.87]), for males (RR = .79 [95% CI, .69-.91]), for 24-hour recall (RR = .74 [95% CI, .63-.86]), and for a quality score of more than 8 stars (RR = .78 [95% CI, .61-.98]). Conclusions There is no significant evidence for concluding that dietary MUFA is associated with a reduced risk of overall stroke. However, higher MUFA intake seems to be associated with a reduced risk of hem orrhagic stroke but not ischemic stroke. Duration of MUFA intake and sex are considered as factors affecting the relationship between MUFA intake and stroke risk. Further studies are needed to evaluate the relationship between specific food sources of MUFA (i.e., plant versus animal) and stroke risk.