Can Dietary Saturated Fat Be Beneficial in Prevention of Stroke Risk? A Meta-analysis

We conducted a meta-analysis to summarize available evidence regarding the relation between saturated fatty acid (SFA) intake and stroke risk. We searched multiple electronic databases through February 2016. Log relative risks (RRs) with 95 % confidence intervals (CIs) of the highest versus the lowest for cohort studies were weighed by the inverse variance method to obtain combined RRs. 15 prospective studies including 476,569 individuals and 11,074 strokes were included. Higher SFA intake was associated with reduced overall stroke risk [RR = 0.89 (95 % CI 0.82-0.96)] and fatal stroke risk [RR = 0.75 (95 % CI 0.59-0.94)]. Subgroup analysis indicated that higher SFA intake was associated with reduced stroke risks for East-Asians [RR = 0.79 (95 % CI 0.69-0.90)], for dose <25 g/day [RR = 0.81 (95 % CI 0.71-0.92)], for males [RR = 0.85 (95 % CI 0.75-0.96)], and for individuals with body mass index (BMI) <24 [RR = 0.75 (95 % CI 0.65-0.87)], but not for non East-Asians, females, and individuals with dose ≥25 g/day and BMI ≥24. This meta-analysis reveals that higher SFA intake is inversely associated with risk of stroke morbidity and mortality with race, sex, and BMI as key factors influencing this risk. There seems to be a threshold of SFA intake for inverse relation of SFA intake with stroke. However, the stroke-reducing or -increasing effects for specific subtypes and specific food sources of SFA can be concealed. Functions of specific subtypes of SFA (e.g. lignoceric acid) and specific food sources of SFA (i.e. plant vs. animal) in relation to stroke need to be clarified in further studies.