A report, published in September 2019, on cardiovascular events among vegetarians in the EPIC-Oxford cohort garnered much media attention with its striking result that vegetarians (which included vegans) had a 20% higher rates of total stroke than meat-eaters, which was mostly attributed to hemorrhagic stroke (1).
Despite this increased risk of hemorrhagic stroke, vegetarians actually had lower rates of total cardiovascular events (strokes plus heart attacks).
Vegans and vegetarians in this study had lower total and non-HDL cholesterol levels compared to meat-eaters, and previous research has shown an association between low total and LDL cholesterol levels and an increased risk of hemorrhagic stroke. However, lower cholesterol has also been associated with lower rates of ischemic heart disease and ischemic stroke, more than making up for a potential increased risk of hemorrhagic stroke. In this current study, vegetarians had a net result of 7 fewer deaths from heart disease and all stroke, per 1,000 people over a 10-year period.
The study authors also noted that vegetarians had lower levels of vitamin B12, which may play a role in risk for hemorrhagic stroke. Due to a relatively small number of vegans in this study, no firm conclusions can be drawn about stroke risk among vegans. It’s important that vegetarians and, especially, vegans ensure an adequate supply of vitamin B12 through fortified foods and supplements.
1. Tong TYN, Appleby PN, Bradbury KE, et al. Risks of ischaemic heart disease and stroke in meat eaters, fish eaters, and vegetarians over 18 years of follow-up: results from the prospective EPIC-Oxford study. BMJ. 2019 Sep 4;366:l4897.