The flavonoids found in fruit, vegetables, wine and tea are potent antioxidants and have antiplatelet effects (Biochem Pharmacol, 1987; 36: 317-22). Although flavonoids have a more direct effect in preventing ischaemic stroke, they can also reduce the risk of haemorrhagic stroke (JAMA, 1995; 273: 317-22).
But watch out. Heavy drinking can cause heart rhythm disturbances and raise blood pressure, thereby increasing the likelihood of stroke. Indeed, any amount of drinking appears to increase the risk of haemorrhagic stroke by two to four times. Confusingly, moderate alcohol consumption can reduce the risk of ischaemic stroke by inhibiting blood clots while increasing 'good' HDL cholesterol. As always, moderation is key.