Stroke

Vinpocetine given by intravenous injection has been reported to improve some biochemical measures of brain function in stroke patients.^1,2 A controlled trial found intravenous vinpocetine given within 72 hours of a stroke reduced some of the losses in brain function that typically follow a stroke.³ However, the reliability of human stroke research using vinpocetine has been questioned,^4,5 and more double-blind trials are needed. No studies using oral vinpocetine for treating acute strokes have been published.

Researchers have found an association between diets low in magnesium and increased risk of stroke, an effect explained partially, but not completely, by the ability of magnesium to reduce high blood pressure.⁶ Protection from stroke associated with drinking water high in magnesium has also been reported.⁷ Intravenous magnesium given immediately after a stroke has been proposed as a treatment for reducing stroke deaths,⁸ but results so far have been inconclusive.⁹

In a double-blind trial, people with atherosclerosis in the carotid arteries were given a palm oil extract containing 160–240 mg of tocotrienols (a vitamin E-like supplement) and approximately 100–150 IU vitamin E per day. After 18 months, they had significantly less atherosclerosis or less progression of atherosclerosis compared to a group receiving placebo.¹⁰ Vitamin E plus aspirin, has been more effective in reducing the risk of strokes and other related events than has aspirin, alone.¹¹ However, most preliminary trials have shown no protective effects from antioxidant supplementation.^{12,13,14,15,16,17} A large Finnish trial concluded that supplementation with either vitamin E or beta-carotene conferred no protection against stroke in male smokers,¹⁸ although a later review of the study found that those smokers who have either hypertension (high blood pressure) or diabetes do appear to have a reduced risk of stroke when taking vitamin E.¹⁹

People with high risk for stroke, such as those who have had TIAs or who have a heart condition known as atrial fibrillation,²⁰ are often given aspirin or anticoagulant medication to reduce blood clotting tendencies. Some natural inhibitors of blood clotting such as garlic,^21,22,23fish oil,²⁴ and vitamin E,^25,26 may have protective effects, but even large amounts of fish oil are known to be less potent than aspirin.²⁷ Whether any of these substances is an adequate substitute to control risk of stroke in high-risk people is unknown, and anyone taking anticoagulant medication should advise their prescribing doctor before beginning use of these natural substances.

Narrowing of the neck arteries (carotid stenosis) caused by atherosclerosis is a risk factor for stroke. Preliminary diet studies have found that people who eat foods high in antioxidants such as vitamin C and vitamin E have less carotid stenosis.^28,29

In a double-blind trial, people with atherosclerosis in the carotid arteries were given a palm oil extract containing 160–240 mg of tocotrienols (a vitamin E-like supplement) and approximately 100–150 IU vitamin E per day. After 18 months, they had significantly less atherosclerosis or less progression of atherosclerosis compared to a group receiving placebo.³⁰ Vitamin E plus aspirin, has been more effective in reducing the risk of strokes and other related events than has aspirin, alone.³¹ However, most preliminary trials have shown no protective effects from antioxidant supplementation.^{32,33,34,35,36,37} A large Finnish trial concluded that supplementation with either vitamin E or beta-carotene conferred no protection against stroke in male smokers,³⁸ although a later review of the study found that those smokers who have either hypertension (high blood pressure) or diabetes do appear to have a reduced risk of stroke when taking vitamin E.³⁹

People with high risk for stroke, such as those who have had TIAs or who have a heart condition known as atrial fibrillation,⁴⁰ are often given aspirin or anticoagulant medication to reduce blood clotting tendencies. Some natural inhibitors of blood clotting such as garlic,^41,42,43fish oil,⁴⁴ and vitamin E,^45,46 may have protective effects, but even large amounts of fish oil are known to be less potent than aspirin.⁴⁷ Whether any of these substances is an adequate substitute to control risk of stroke in high-risk people is unknown, and anyone taking anticoagulant medication should advise their prescribing doctor before beginning use of these natural substances.