Quality of Plant-Based Diet and Risk of Total, Ischemic, and Hemorrhagic Stroke

Objective To determine whether a healthful plant-based diet is related to lower stroke risk, we examined the associations of plant-based diet quality with risk of total, ischemic, and hemorrhagic stroke. Methods The participants were 73,890 women in Nurses' Health Study (NHS; 1984-2016), 92,352 women in NHSII (1991-2017), and 43,266 men in Health Professionals Follow-Up Study (1986-2012) without cardiovascular disease and cancer at baseline. Plant-based diet quality was evaluated by the overall plant-based diet index (PDI), the healthful PDI (hPDI), and the unhealthful PDI (uPDI). Participants who reported that their meat and/or fish intakes were 0 or <1 serving per month were categorized as vegetarians, and others were classified as nonvegetarians. Strokes with available medical records were subtyped as ischemic or hemorrhagic. Results During the follow-up, 6,241 total stroke cases (including 3,015 ischemic and 853 hemorrhagic strokes) were documented. Compared to participants with the lowest PDIs, among participants with the highest PDIs, the hazard ratios (HRs) for total stroke were 0.94 (95% confidence interval 0.86-1.03) for PDI, 0.90 (0.83-0.98) for hPDI, and 1.05 (0.96-1.15) for uPDI. Participants in the highest hPDI showed marginally lower HR for ischemic stroke (0.92 [0.82-1.04]) and no consistent associations for hemorrhagic stroke. We observed no association between a vegetarian diet and total stroke (1.00 [0.76-1.32]), although the number of cases was small. Conclusion Lower risk of total stroke was observed by those who adhered to a healthful plant-based diet.