Beta
carotene
Carotenes especially beta carotene occurs abundantly in nature. It is
estimated that nearly more than 500 different carotenoids like
β-carotene, α-carotene, lutein, cryptoxanthins, zea
xanthins...etc
distributed in the plant and algae world. Although many of these have
proven independent functions, however, nearly 50 or more can be
metabolized to vitamin-A in the human body. β-carotene is the most
prevalent carotenoid in the plant sources of food supply and is also
known as pro-vitamin A.
Roughly, 6 mcg (range vary
widely 6-18 mcg) of ß-carotene is equal to 1 RE (Retinol equivalents)
or 3.33 IU of
vitamin-A.

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| Fruits and vegetables rich in β-carotene.
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Health
benefits of beta carotene
-
Being an important
flavonoid
compound, beta carotene has powerful antioxidant functions, helps body
scavenge free radicals, thereby limiting the damage to cell membranes,
DNA and protein structures in the cell.
-
Dietary intake of foods
high in
β-carotene associated with decreased risk of cardio-vascular disease
and oral cavity and lung cancers.
-
When converted to vitamin
A in the intestines it has all the functions
of vitamin A such as visual cycle, reproduction (sperm production),
maintenance of
epithelial functions, growth and development.
Natural
sources of beta carotene
Almost all the green-yellow-orange (GYO) vegetables and fruits are rich
sources of beta carotene. Some of the common
vegetables/fruits/herbs/nuts per 100 g of weight with highest
content of ß-carotenes are:-
(source: USDA nutrient database)
Beta
carotene supplements?
The benefits
of beta carotene
supplements, however, has surprisingly
unexpected results. Two large scale prospective randomized studies, on
high risk cigarette smokers, of β-carotene (a-tocopherol, b-carotene
(ATBC) cancer prevention study and the β-carotene and retinal efficacy
trial (CARET) found that b-carotene increased rates of lung cancer in
the supplemented group.
On the
contrary, as mentioned above, high
dietary intake of foods rich in β-carotene is associated with
decreased risk of cardio-vascular disease and cancers. Dietary intake
of foods high in carotene offers protection against coronary artery
disease and cancers. However, β-carotene supplementation appears
harmful to health, especially in high risk smokers.
Carotenemia
Addition of
excess plant
sources of beta carotene causes deposition of
carotenes in the skin and tissues result in a harmless condition
known
as carotenemia. The condition recedes itself once foods rich in
carotenes withdrawn
from the diet.
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