Prevention of cardiovascular disease
A high dietary carotene intake is associated with a lower risk of cardiovascular disease. Beta-carotene may inhibit the oxidative damage to cholesterol and the lining of the arteries that initiates the process of hardening of the arteries (atherosclerosis). However, it appears that beta-carotene is less effective in protecting against cardiovascular disease than vitamin E, probably because vitamin E protects against oxidative damage to cholesterol better than beta-carotene.
Leukoplakias are white plaquelike lesions occurring anywhere in the mouth that are reactions to irritation, such as cigarette smoking or tobacco chewing. It is often a precancerous lesion that may develop into mouth or throat cancer. Beta-carotene has been found to be clinically effective in the treatment of leukoplakia. To date, there have been seven clinical trials showing that beta-carotene supplementation (30-180 mg per day) produces regression in anywhere from 15 to 71 percent of people with leukoplakia.
Low immunity and immune support
Beta-carotene has demonstrated a number of immune-enhancing effects. Originally it was thought that the immune-enhancing properties of beta-carotene were due to their being converted to vitamin A. researchers now know that carotenes exert many immune-system-enhancing effects independent of any vitamin A activity. In addition to a great number of experimental studies showing immune-enhancing effects with beta-carotene supplementation, there are also several clinical studies in both healthy human volunteers and those with evidence of impaired immune function. For example, in one study with healthy subjects, beta-carotene given at a dosage of 180 mg daily (approximately 300,00 IU of vitamin A activity) significantly increased the frequency of helper/inducer T cells (white blood cells that play a critical role in fighting infection) by approximately 30 percent after only seven days.
However, rather than supplementing the diet with synthetic beta-carotene, it may be more advantageous to use carotene from natural sources or increase the intake of carotene-rich foods. For example, in a study in healthy college students, better results in improving immune function were shown in the group that consumed approximately 15 mg beta-carotene per day from carrots compared to those who took 15 mg of synthetic beta-carotene.
Beta-carotene has become the treatment of choice for photosensitivity disorders (skin rashes induced by the sun) even in conventional medical circles. It is most effective in the treatment of a condition named erythropoietic protoporphyria (EPP), while its effectiveness in other photosensitivity disorders has also been demonstrated, but not to the same degree. For this application, it is recommended that you consult a physician.
There are two primary sources of beta-carotene on the market; synthetic beta-carotene and natural carotene extracts. Natural beta-carotene is available derived from carrot oil, the algae Dunaliella salina (e.g., Betatene), and from palm oil (e.g., Caroplex, Caromin). The natural forms appear to offer advantages over the synthetic form in that they contain a broader range of carotenes, exert more antioxidant protection, and are better absorbed. Beta-carotene, whether natural or synthetic, is available in capsules or tablets.
Cautions and Warnings
Supplementation may cause the skin to turn a yellow to orange hue (carotenodermia). This change is not harmful.
Possible Side Effects
Supplementing the diet with beta-carotene has not been shown to produce any significant side effects other than a possible yellowing of the skin. Dosages greater than 180 mg per day may produce loose stools, but this side effect usually clears quickly and does not necessitate stopping treatment.
Food and Nutrient Interactions
Absorption of beta-carotene may be enhanced by taking it with food, particularly a meal with some fat or oil. High dosages of beta-carotene (e.g., greater than 15 mg / day) may increase the need for vitamin E. Olesra (a fat substitute) as well as sources of dietary fiber (psyllium, pectin, guar gum, etc.) may decrease the absorption of beta-carotene. Beta-carotene supplementation may decrease the absorption of other beneficial carotenes such as lutein and lycopene. A deficiency of zinc, vitamin C, protein, or thyroid hormone will impair the conversion of beta-carotene to vitamin A.