A stroke occurs when blood flow to an area of the brain is cut off. When this happens, the cells are cut off from oxygen and begin to die. When brain cells die during a stroke, abilities controlled by that area of the brain, such as memory and muscle control, are lost.1
Impact of coffee on strokes
A study of 26,556 male Finnish smokers reported that the relative risk of developing a non-hemorrhagic stroke was reduced by 12% with the consumption of 4-5 cups of coffee per day. When they consumed 6 or more cups of coffee per day, this risk reduction was increased to 23%. A follow up study on 34,670 women was then carried out. The results showed that consumption of 2-5 cups of coffee per day would reduce the risk of developing a total stroke, cerebral infarction, or subarachnoid hemorrhage by 22%-25%. There was no reduced risk of developing intra-cerebral hemorrhage.
Another study of 83,076 women also reported a 20% reduced risk of stroke with the consumption of 2-4 cups of coffee per day, compared to the consumption of 1 cup of coffee per month. The association was stronger among past and never smokers, with 4 cups of coffee per day reducing the risk of stroke by 43%. Other drinks containing caffeine, such as tea and caffeinated soft drinks, where not associated with strokes, or a reduced risk in developing them.2
Sources
1 Stroke.org - What is stroke?
2 Coffee & Health - Coffee and stroke