Phytochemicals
Nutrients found in vegetables and fruits, have health benefits. The
1995 Dietary Guidelines for Americans, released by the US government,
states that "The antioxidant nutrients found in plant foods (vitamin
C, carotene, vitamin E, and the mineral selenium) are presently of great
interest to scientists and the public because of their potentially beneficial
role in reducing the risk of cancer and certain other chronic diseases."
Many claims about plants and health have not been tested in clinical,
double-blind trials or by other traditional means. Should we believe them?
The universal acceptance of the benefits of plant phytochemicals-substances
found in plants that might play a role in preventive health-might at least
nudge us toward the willingness to accept the possibility that plants
have benefits.
Some of the research on phytochemicals is funded by the National Cancer
Institute (NCI), which has launched a multimillion-dollar project to find,
isolate, and study phytochemicals. The result of this and similar research
is an ever-increasing wealth of data that points to the possible positive
effects of fruits and vegetables on our health.
For example, research has shown that broccoli contains a substance,
sulforaphane, that may prevent, even cure, breast cancer. Citrus fruits
contain limone, which increases the activity of enzymes that eliminate
carcinogens. Cabbage, Brussels sprouts, cauliflower, and similar vegetables
contain indoles, which might lower the risk of breast cancer. Currently
in the news is genistein, a substance found in soy beans which may block
tumor growth, and lycopene, a component of tomatoes which has been linked
to reduced risk of prostate cancer.
One of the results of this research is that the NCI recommends that
we eat five servings of vegetables and three servings of fruits per day.
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