Beta-carotene is a member of the carotenoid family and has over 500 relatives.
Carotenoids are yellow-to-red pigments found in all green plant tissues and in some
species of algae. So far 21 different carotenoids have been found in human blood. The
most abundant ones are alpha-carotene, beta-carotene, lutein, lycopene, cryptoxanthin and
zeaxanthin. A molecule of alpha-carotene, beta-carotene, or cryptoxanthin can be split
into two molecules of vitamin A in the body but the conversion of beta-carotene is by far
the most effective. The six carotenoids are all antioxidants. They are very effective
in neutralizing a highly reactive for of oxygen called singlet oxygen but also, to some
extent, act to break up the chain reactions involved in lipid peroxidation.
Numerous studies have shown that people who consume a diet rich in dark yellow orange
vegetables (carrots) and dark green vegetables (broccoli) are much less likely to develop
cancer and heart disease. It has also been established that people with low levels of
beta-carotene in their blood have a higher incidence of heart disease and cancer,
particularly lung cancer. The National Cancer Institute endorsed a study which found
that women who consume lots of beta-carotene rich fruits and vegetables have a lower
chance of getting cancer, including breast cancer. The Institution says that regularly
eating lots of fruits and vegetables plays a key roll in cancer prevention, but whether
the preventative action comes from beta-carotene or other nutrients in the produce has
yet to be determined.
For people who don't like eating their fruits and vegetables, a beta-carotene supplement
pill was introduced into the market. Millions of vegetable hating Americans hoped that
by taking a pill instead of eating vegetables, they could get the same rewards as their
counterparts who enjoy the taste of fruits and vegetables. But officials at the
National Cancer Institute released the results of two large studies designed to put the
benefits of beta-carotene supplements to the test. One followed 22,071 doctors who for
12 years smokers had to be stopped prematurely because it seemed to me making the rate of
death from cancer and heart disease worse. Taking a simple chemical supplement is not
the same as eating a vegetable. Scientists suspect there are other natural ingredients
that work with vitamins to promote health.
It is also possible that a beta-carotene supplement derived from natural sources and
formulated so as to preserve the normal carotene ratio in the blood may be of benefit for
people at high risk for cancer and cardiovascular disease. This, however, needs to
proven. So, until the remaining riddles in the carotene puzzle are solved, the prudent
course of action is to avoid smoking and exposure to second-hand smoke and to increase
the intake of vegetables and fruits.
In 1981 it was suggested that beta-carotene is the active component in the protective
vegetables and that supplementing with beta-carotene might prevent certain cancers. The
idea was based on the fact that took 50 mg of beta-carotene every other day. Another
involved 18,314 smokers, ex-smokers, and asbestos workers. Not only did beta carotene
produce no measurable health benefits, but the study of beta-carotene is an antioxidant
and the most abundant carotenoid in vegetables. There was also considerable evidence to
the effect that vitamin A prevents or retards certain cancers, so that beta-carotene is
readily converted to vitamin A in the liver and intestine was seen as an added bonus.
More recent research suggests that beta-carotene's prevention effect is due to its
antioxidant property rather than to its ability to form vitamin A.
People need to learn to take a little bit of time to eat good, healthy foods instead of
relying on pills. I feel that more people need to be educated about what beta carotene
can do for you. If more people ate enough beta-carotene, maybe doctors would have less
patients to treat. Beta-Carotene really can help prevent a lot of diseases. It's almost
like a natural life-saver. Now I understand why my parents are always telling me to "eat
my vegetables, they are good for you."
SOURCES
1. "Beta-Carotene: A Nugget of Nutritional Gold.", Marilyn Carnell, Ph.D., R.D
Better Homes and Gardens, October 1992: 64-66.
2. "Beta No More", Christine Gorman. Time Magazine, Jan. 29, 1996: pg. 66.
3. Peto , R, et al. Can dietary beta-carotene materially reduce human cancer rates?
Nature, Vol. 290, March 19, 1981, pp. 201-208.
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