Beta-carotene

Used for antioxidant effects in the prevention of cancer and cardiovascular diseases.

Beta-carotene is a member of the carotene family, the most widespread group of naturally occurring pigments in nature. Carotenes are a highly colored (red, orange, and yellow) group of fat-soluble antioxidants. Some carotenes, such as beta-carotene, can also be converted in the body to vitamin A (that is why it is categorized as a vitamin). Over six hundred carotenoids have been identified, but only between thirty and fifty are believed to have vitamin A activity. Beta-carotene has long been considered the most important carotene because it can easily be converted into vitamin A. however, although it has excellent antioxidant activity, several other carotenes (e.g., lycopene and lutein) have been shown to have greater antioxidant activity. Therefore, beta-carotene’s claim to be the most important carotene may no longer be valid.

The conversion of beta-carotene to vitamin A is dependent on several factors, including protein status, thyroid hormones, zinc, and vitamin C. The rate of conversion diminishes as beta-carotene intake increases and when serum vitamin A levels are adequate. Therefore, beta-carotene does not lead to vitamin A toxicity.

In general, the carotenes are present in highest concentrations in highly colored vegetables and fruit. Beta-carotene is the predominant carotene in most green leaves; in general, the greater the intensity of the green color, the greater the concentrations of beta-carotene. Orange-colored fruits and vegetables – carrots, apricots, mangoes, yams, squash, and so on – are also good food sources. The red and purple vegetables and fruits – such as tomatoes, red cabbage, berries, and plums – contain a large portion of other types of carotenes as well as another group of pigments known as flavonoids.

Carotenes are used as antioxidants in the prevention of cancer, and cardiovascular disease, as immune – enhancing agents, and in the treatment of leukoplakia and photosensitivity.