Beta-carotene is one of the class of over 600 carbon-based compounds known as carotenoids. Beta-carotene is found in a variety of plants, and provides the color to oranges and carrots. In nature, beta-carotene protects these food sources from the degrading effect of oxygen. Beta-carotene is a fat-soluble chemical, requiring the presence of fatty acids to assist in its absorption into the body. In addition to carrots, beta-carotene is abundant in broccoli and other green vegetables.
Beta-carotene is very similar in its structure to vitamin A (also known as retinol), a chemical essential to human health. Vitamin A is of particular importance to both vision and healthy bone development. Beta-carotene acts as a precursor to vitamin A, where the body will use beta-carotene to manufacture vitamin A if a deficiency in the vitamin is detected. It is for this reason that beta-carotene is also known as a provitamin A.
Beta-carotene has attracted significant attention in the medical community in recent years due to its recognized powers as an antioxidant. Antioxidants are a class of chemicals that are ingested into the body from a variety of food sources. Each has an ability to neutralize the effect of the chemical agents known as free radicals, whose electrochemical composition compels them to seek out molecules within the body from which more electrons can be taken, so as to convert the radical into a stable molecule. The most common and the most potentially destructive of the free radicals are those composed of unstable oxygen molecules, O2. The actions of the free radicals, if unimpeded, will trigger a chain reaction of electron thievery, as each molecule attempts to correct its own electron imbalance. These chain reactions are at the root of the cellular damage caused within the body that potentially leads to the formation of cancers, and is believed to precipitate aging.
Antioxidants such as beta-carotene scavenge the cardiovascular system, neutralizing the O2 radical through a donation of an electron to the radical.
There is considerable debate in the scientific community as to the effect of additional dietary supplements of beta-carotene as antioxidants, as opposed to the ingestion of these chemicals through natural food sources. There is a clear correlation between the increased daily consumption of fruits and vegetables, and the lower risk of cancers and heart disease.