When we think about the people most at risk of a stroke, we tend to think of the elderly or the unfit. Well, if you have a B-vitamin deficiency, you’re in for a shock: you may also be at risk.
It’s now known that deficiencies in folate, B6, and B12 have been linked to elevated blood homocysteine levels. This can pose serious risks of chronic diseases, including stroke.
The Health Professional Follow-up Study was designed to establish just how intakes of folate and vitamins B6 and B12 could influence ischemic and hemorrhagic stroke1.
The 14-year study, published in the journal Stroke, involved 43,732 men aged between 40 and 75 who had no history of cardiovascular diseases or diabetes. The men were followed from 1986 to 2000, with dietary assessments taken every four years to calculate their individual nutritional status.
At the end of the study, the participants were divided into quintiles according to their intakes of B vitamins. Their relative risk of stroke was estimated by comparing the incidence of stroke in a particular dietary intake quintile. Elevated risk levels were found with those in the lowest B vitamin intake group.
Results were adjusted to account for other factors that contribute to stroke: cigarette smoking; body mass index (BMI); physical activity; history of hypertension and hypercholesterolemia; aspirin use; and intakes of alcohol, fiber, potassium, vitamin E, and total energy.
The results could have many of us - not just men - rethinking our diet.
When factors such as poor diet, lack of exercise, genetic disorders and other health conditions were accounted for, the risk of stroke was clearly linked to an individual’s intake of folate and B12.
In fact, men in the highest quintile of folate intake had an approximately 30% lower risk of ischemic stroke than those in the lowest quintile.
Intake of vitamin B12 - but not B6 - was also inversely related to risk of ischemic stroke, but not hemorrhagic stroke.
Specifically, it appears that something as simple as a higher intake of folate and vitamin B12 can reduce the risk of ischemic stroke.
But why? And what do these specific B vitamins have to do with stroke?