Dietary patterns and stroke: a systematic review and re-meta-analysis.

The effect of diet on the development of stroke has recently achieved much interest by various research groups, but with inconclusive results. The aim of the present review was to systematically present and discuss the up to date available research regarding the relationship between adherence to dietary patterns and stroke. Studies included were observational and randomized clinical trials. Internet searches until May 31, 2014, retrieved 152 potentially relevant papers; of them, 34 were excluded on the basis that did not report data on humans, 3 were in language other than English, 2 were excluded because they had a cross-sectional design, 3 because they reported data on secondary prevention and 82 were excluded on the basis of irrelevant research. One article was a recent meta-analysis on Mediterranean diet, stroke, cognitive impairment and depression and was used as a basis for a re-meta-analysis with the additional papers published after the publication of the later meta-analysis. The existing evidence suggests that adherence to healthy dietary patterns (i.e., Mediterranean or DASH or plant based "prudent") was associated with reduced risk for stroke, whereas limited data exist supporting a detrimental effect of westernized dietary patterns. Moreover, the applied re-meta-analysis, based on a total sample of 195,875 participants enhanced the previously reported meta-analysis underlying a consistent, protective effect of higher adherence to the Mediterranean diet on stroke incidence (pooled relative risk 0.68, 95% CI 0.58, 0.79). Thus, a healthy dietary pattern exerts a beneficial effect on stroke incidence and mortality, adding a new direction toward stroke prevention on population level.