Tocotrienols may offer protection against atherosclerosis by preventing oxidative damage to LDL cholesterol.³ In a double-blind trial in people with severe atherosclerosis of the carotid artery—the main artery supplying blood to the head—tocotrienol administration (200 mg per day) reduced the level of lipid peroxides in the blood. Moreover, people receiving tocotrienols for 12 months had significantly more protection against atherosclerosis progression, and in some cases reductions in the size of their atherosclerotic plaques, compared with those taking a placebo.⁴

Tocotrienols are lipid-soluble antioxidant molecules that are closely related to tocopherols. Together, tocotrienols and tocopherols make up the family of compounds referred to as vitamin E. These compounds have a critical role in preventing LDL particle oxidation, thus reducing oxidative damage to blood vessels.⁵ Some clinical trials have found tocotrienols lowered cholesterol levels, but evidence is conflicting. A meta-analysis of 15 clinical trials found tocotrienol supplementation may increase HDL-cholesterol levels, but is unlikely to reduce total or LDL-cholesterol levels.⁶

 

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.⁷ Vitamin E plus aspirin, has been more effective in reducing the risk of strokes and other related events than has aspirin, alone.⁸ However, most preliminary trials have shown no protective effects from antioxidant supplementation.^{9,10,11,12,13,14} A large Finnish trial concluded that supplementation with either vitamin E or beta-carotene conferred no protection against stroke in male smokers,¹⁵ 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.¹⁶

People with high risk for stroke, such as those who have had TIAs or who have a heart condition known as atrial fibrillation,¹⁷ are often given aspirin or anticoagulant medication to reduce blood clotting tendencies. Some natural inhibitors of blood clotting such as garlic,^18,19,20fish oil,²¹ and vitamin E,^22,23 may have protective effects, but even large amounts of fish oil are known to be less potent than aspirin.²⁴ 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.