Like heart attacks, strokes are considered to be a type of cardiovascular disease and greatly influenced by high homocysteine levels. Strokes affect the arteries leading to and from the brain and can be caused by either a blood clot or a blood vessel rupturing. These both in turn, block vital oxygen and nutrients reaching the brain, starving cells and causing potentially irreparable damage.

Results from the Framingham Study, which is following three generations of the population of the US town of Framingham, have confirmed the key role homocysteine plays as a predictor for stroke. Individuals in the highest homocysteine level quartile have an 82% increased chance of stroke, emphasising homocysteine as an independent causative agent of stroke in elderly persons.