Beta Carotene

DESCRIPTION

Beta carotene belongs to a natural chemical family known as carotenes or Carotenoids . Widely found in plants, Carotenoids give fruits, vegetables, and other plants their distinctive colours. Beta carotene is significant from a nutritional perspective, because the body can easily transform it to Vitamin A . It is the best source of Vitamin A , since the body will only make as much as is necessary. Vitamin A supplements, on the other hand, can be toxic when taken excessively. A variety of health benefits have been documented for food sources of beta carotene.

SUGGESTED INTAKES

For nutritional purposes, the recommended dosage of beta carotene is the amount needed to obtain the optimal amount of Vitamin A . For example, three mg (5000 IU) of beta carotene supplies 5000 IU of vitamin A. The recommended amount of Vitamin A varies with age and sex. Refer to Vitamin A for further information.

SUPPLEMENTAL USES

Antioxidant:
Beta carotene possesses valuable antioxidant activity which may help to protect against free radical damage initiated by sunlight, pollution etc.

Heart disease:
It has been documented that beta carotene can protect against heart disease (1).

Eye Health:
Dietary beta carotene can slow the progression of cataracts. In addition, it may also prevent macular degeneration, which is associated with fine visual perception (2,3).

Osteoarthritis:
Dietary beta carotene may also slow the progression of osteoarthritis (4).

SAFETY

Beta carotene has been found to be very safe when taken at recommended dosages. Side effects that have been reported from beta carotene overdose are Diarrhoea and a yellowish tinge to the hands and feet. These minor problems disappear once consumption is halted or decreased.

Smokers are advised not to take individual high level beta carotene supplements.

Those who work with or have been exposed to asbestos are advised to avoid beta carotene supplements.

INTERACTIONS AND CONTRA-INDICATIONS

Several drugs may interact with beta-carotene. Colchicine and methotrexate decrease absorption of beta carotene. If one is taking a cholesterol-lowering drug such as colestipol or cholestyramine, he/she may require extra beta carotene.

FOOD SOURCES

Good sources of beta-carotene are dark green and orange-yellow vegetables. These include carrots, sweet potatoes, squash, spinach, romaine lettuce, broccoli, apricots, and green peppers.

REFERENCES

1. Kohlmeier L and Hastings SB. Epidemiologic evidence of a role of Carotenoids in cardiovascular disease prevention. Am J Clin Nutr 62(suppl.): 1370S-1376S, 1995.
2. Carson C, Lee S, De Paola C, et al. Antioxidant intake and cataract in the Melbourne Visual Impairment Project. Am J Epidemiol 139: S18, 1994.
3. Seddon JM, Ajani UA, Sperduto RD, et al. Dietary Carotenoids , vitamins A, C, and E, and advanced age-related macular degeneration. JAMA 272: 1413-1420, 1994.
4. McAlindon TE, et al. Do antioxidant micronutrients protect against the development and progression of knee OA? Arth Rheum 39: 648-656, 1996.