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In observational studies, vitamin E has been shown to reduce the risk
of fatal and non-fatal heart attacks.22 Researchers are also
exploring its role in stroke prevention. Preliminary studies show that
alpha-tocopherol, a form of vitamin E, decreases strokes that come from
a loss of blood flow to the brain, but increases the risk of strokes that
come from bleeding in the brain.23
Vitamin E supplementation may play a role in maintaining the integrity
of cellular immunity, a component of the immune system that deteriorates
as we age. Cellular immunity permits us to continue to resist certain
infections.24
Vitamin E has shown marginal benefit in retarding the mental deterioration
of Alzheimer's disease.25
Laboratory studies in rats have shown that vitamin E can improve blood
sugar control in diabetes, potentially reducing the number of complications
due to that disease.26
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Vitamin C may play a role in reducing the risk of developing heart disease.
It has been shown to improve the health of blood vessels in patients with
coronary artery disease. It may also have benefits in people with other
risk factors for heart disease, such as high cholesterol, high blood pressure,
diabetes, smoking and high blood levels of homocysteine.27
Studies have observed that older adults who take vitamin C supplements
have lower blood pressure readings, which could explain some of the decreased
risk of heart disease and strokes.28
Some studies have shown that moderate alcohol consumption reduces the
risk of heart disease. Interestingly, the National Health and Nutritional
Examination Survey found that people with angina who take vitamin C and
drink alcohol moderately suffer less from their angina than those who
take vitamin C and do not drink alcohol.29
The National Health and Nutrition survey also found that women with a
high intake of vitamin C have a lower incidence of gallstones.30
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Carotenoids are the naturally occurring pigments that give fruits and
vegetables their bright colors. There are dozens of carotenoids and most
of them have antioxidant properties. Combining carotenoids with one another
or with other categories of antioxidants such as vitamins increases their
antioxidant activity. Some of the best studied and best understood carotenoids
are lycopene, lutein, zeaxanthine, and beta-carotene.
 Lycopene
Lycopene is the pigment that gives tomatoes their red color. It appears
to have some benefit in reducing the risks of coronary artery disease,
and several studies are underway now to explore that benefit.31
Lutein
and Zeaxanthine
Lutein and zeaxanthine often occur together in green leafy vegetables,
and are also found in such foods as corn, egg yolk, orange peppers, kiwi,
and various kinds of squash. Dietary lutein and zeaxanthine are the two
carotenoids most clearly associated with a decreased risk of age-related
macular degeneration, the leading cause of blindness among adults.32
Beta-carotene
Beta-carotene is a form of vitamin A. Beta-carotene can decrease
the amount of damage free radicals do to a cell's DNA. Such DNA damage
is thought to be one mechanism that causes cancer, and indeed, some early
studies suggested that beta-carotene might reduce the risk of cancer.
Two large studies were designed to look at the relationship between beta-carotene
and cancer prevention. Male cigarette smokers, already at high risk for
lung cancer, received supplements of beta-carotene and either vitamin
E or retinol. In both studies, the risk of lung cancer was higher among
those who took the antioxidants.33 The studies were terminated
and the results made public, to warn those smokers self-treating with
beta-carotene.
One of those studies also looked at the risk of stroke among smokers taking
beta-carotene and vitamin E. The risk of a stroke caused by bleeding into
the brain was increased with beta-carotene supplements.
Interestingly, in a study of women who took supplements of beta-carotene,
there was no increased risk of either heart disease or stroke; nor was
there any benefit.34
A review of the various studies of beta-carotene and cancer reveals that
carotenoids can improve health when obtained through one's diet, but that
high dose supplements can have adverse effects, especially by those at
highest risk of certain cancers, such as smokers or asbestos workers.35
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