Background and objectives: Vegetarian and prudent diets are associated with several health benefits but their role in stroke epidemiology is not as clear. This study aimed to evaluate stroke risk with vegetarian, low-animal, and high-animal diets.
Methods and study design: Studies reporting stroke risk with high versus low use of vegetarian or low/high-animal diets were identified by conducting literature search in Ebsco, Ovid, PubMed, Science Direct, and Web of Science databases. Relative risks (RRs) of stroke between high and low use of vegetarian, low-animal, and high-animal were pooled to achieve overall estimates. Relationship between stroke risk and increasing quantiles of dietary patterns was sought by performing metaregression analyses.
Results: 17 studies (932545 individuals; follow-up 11.7 years [95% confidence interval (CI): 9.5, 13.9]) were included. Compared to low use, high use of vegetarian and low-animal diets was associated with lower risk of hemorrhagic stroke (RR: 0.71 [95% CI: 0.47, 0.96] and 0.82 [95% CI: 0.64, 0.99]), ischemic stroke (RR: 0.78 [95% CI: 0.66, 0.91] and 0.70 [95% CI: 0.45, 0.95]) and total stroke (RR: 0.84 [95% CI: 0.71, 0.96] and 0.72 [95% CI: 0.61, 0.83]) respectively. Dose-response analyses further supported these findings. High use of high-animal diet was associated with relatively higher risk of stroke [RR: 1.12 [95%CI: 0.94, 1.29]. In vegetarians, relative to high use of vegetables, high use of fruits posed lower risk of stroke.
Conclusions: Stroke risk is lower with more use of a vegetarian or low-animal diet but relatively higher with more use of a high-animal diet.