Carotenoids are a major topic in nutrition and health
circles today. Why are they important? Because vitamin A, long known to be crucial for
normal vision, has been discovered to have a whole host of diverse biological functions.
Its role in controlling the way in which cells divide, develop, and mature has become an
area of much interest among scientists.
Eye Structure and function
Research has shown that people who consumed 3.5 or more servings of fruits and
vegetables (in which carotenoids occur naturally) daily had an enhanced eye health.
Immune System Enhancement
Studies suggest that carotenoids enhance immune function by a variety of mechanisms.
Cardiovascular health is improved by 50% in a group of men who took beta-carotene
supplements every other day for five years.
Dr. Richard Cutler from the National Institute on Aging, Gerontology Research Center
supports a significant link between lifespan and plasma carotenoid levels. He states that
carotenoids may be biologically active not only as a protective agent, but also as a
Beta-carotene is the most well-known of the carotenoids and
the predominate one in carrots, sweet potatoes, broccoli, and cantaloupe. Beta-carotene,
the molecule that contains two molecules of vitamin A, plays a major role as a contributor
of vitamin A in our diets. In the last few years, food scientists have been able to
measure not only beta-carotene in fruits and vegetables, but also numerous other
carotenoids. Today we know that provitamin A carotenoids include approximately 50
carotenoids which can be converted into at least one molecule of vitamin A. The other
carotenoids (some 600 total in nature) may have important metabolic effects on the body
independent of vitamin A. These as yet unidentified functions need to be considered when
interpreting studies that claim health promotion properties from carotenoid rich
Carotenoids are converted to vitamin A mainly in the intestine and liver. About 10% of
dietary carotenoids are converted to vitamin A in the body and contribute 25% of our total
vitamin A. We now know that many carotenoids also have antioxidant properties and studies
are underway to determine other health benefits of carotenoid metabolites besides the long
accepted role as precursors of vitamin A. Analytical data are available for five of the
carotenoids found in foods and measurable in the blood. These include beta-carotene,
alpha-carotene, lutein, lycopene, and beta-cryptoxanthin.