Stroke risk. Most important know your numbers--know your blood pressure, heart rate and your lipids and keep those under controlled. 120/80 or less is the ideal blood pressure, if above that get treated. If your lipids are high, lower them. Finally, exercise regularly and keep your weight under control to avoid diabetes which also increases stroke risk.
Stroke prevention. Have an strick vegetarian diet or plant based diet with no sodium or salt. Keep your weight low. Keep your cholesterol low ( LDL less that 70). Monitor your blood pressure and keep it as low as possible w/o symptoms. Do regular exercise but not too hard. Take one bay Aspirin every day. Change your family history of your genes ( not possible yet). Meditate and pray.