Greatest benefit found in those who also had high blood sugar or diabetes.
Earlier studies found folic acid protected against a first stroke, but this is one of the first studies of folic acid and stroke in those with diabetes.
The study covered 20,327 men and women with high blood pressure, with or without diabetes, and no history of adverse heart or circulatory events. About half took 10 mg of the blood pressure medication enalapril, with or without 800 mcg of folic acid per day.
Over the 4.5 years of follow-up, those with high fasting blood sugar levels-at or above 126 mg per deciliter of blood (mg/dL)-or those who had diabetes, were twice as likely as those with low fasting blood sugar levels of 90 mg/dL to have had a stroke.
Folic acid reduced chances of stroke across a wide range of fasting blood sugar levels, but the reduction was greatest in those with high fasting blood sugar.
This shows that it is especially important for those who have diabetes, or high blood sugar levels, along with high blood pressure, to take folic acid supplementation.
Reference: American Journal of Clinical Nutrition; January, 2017, Published Online