Vitamins - Dietary Health Benefits

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Highlights	Phytochemicals	Resources
Introduction	Healthy Foods	References
Carotenoids	Dietary Health Benefits

Atherosclerosis is a disease of the arteries in which fatty material is deposited in the vessel wall, resulting in narrowing and eventual impairment of blood flow. Severely restricted blood flow in the arteries to the heart muscle leads to symptoms such as chest pain. Atherosclerosis shows no symptoms until a complication occurs.

Phytochemicals and Heart Protection. Foods containing phytochemicals are associated with heart protection.

Flavonoids. Certain flavonoids, found in both black and green teas, dark chocolate, onions, red wine or red grape juice, and apples, appear to be heart protective. Flavonoids may protect against damage done by cholesterol and help prevent blood clots.
Organosulfurs. Organosulfurs found in onions and garlic have been under investigation for possible beneficial effects on cholesterol levels.
Isoflavones. Soy protein, found in foods like tofu and soy milk, is the most studied source of isoflavones (known as phytoestrogens, or plant estrogens), which some studies indicate might improve blood cholesterol.
Sterols. The plant sterols, including sitosterol, are also proving to be potent cholesterol fighters by blocking the absorption of cholesterol in the intestine.

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Protection against Stroke

A healthy diet rich in fruits and vegetables and low in salt and saturated fat may significantly lower the risk for a first stroke, perhaps by helping to protect against high blood pressure -- a major risk factor for stroke.

Vitamins and Stroke Protection. The effects of antioxidant vitamins and carotenoids (vitamins C or E, or beta-carotene) on stroke have been studied extensively. Most studies have found that these vitamins do not help protect against stroke.

Studies have indicated that, while B vitamin supplements help lower homocysteine levels, they have no effect on heart disease outcomes. Research is under way to evaluate the benefit of vitamins on reducing stroke risk.

Protection against Cancer

Many fresh fruits and vegetables contain chemicals that may fight many cancers, including lung, breast, colon, and prostate cancers. Examples of important cancer fighting foods include cruciferous vegetables (such as cabbage, Brussels sprouts, and broccoli), tomatoes (which contain lycopene), and carrots (which contain alpha-carotene).

Any protective effects of vitamins or specific phytochemical against cancer, however, appear to depend on the cooperative effort among them. Supplements of any vitamins or food chemicals have not shown any benefits.