Alpha and Beta Carotene

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Alpha and Beta carotene are only two of the six hundred or so carotenoids found in nature. Carotenoids are a fat soluble pigment in the red, orange and yellow color range. They are hydrocarbons, made up of long chains of hydrogen and carbon, with no oxygen. Alpha and beta carotene are important to humans because, among other things, they break down into retinol, or Vitamin A, in the body. These two molecules have identical structures except for a double bond on one cyclic group at the end of the molecule being in a different position. Although some sources say alpha is a more potent antioxidant, beta carotene is the form most commonly found in nature and most easily converted to Vitamin A.

We can get retinol, which is preformed vitamin A, from animal sources such as egg yolks and liver. We also make vitamin A from the carotenoids found in plants. Vitamin A is one of the essential fat soluble vitamins, meaning we can't synthesize it in the body, and therefore need to get it from diet. Vitamin A is necessary for normal growth and development, for the immune system to function properly, and for vision.

Alpha and beta carotene are potent antioxidants, which can help to prevent damage to your body from free radicals. Beta-carotene has been shown to reduce UV damage to the skin, and is often used in topical creams and supplements for skin protection. A study by Harvard Medical School suggests that beta-carotene can improve cognitive function, if taken for a long time period. It has also been shown to prevent formation of cataracts. It is good for the heart because it can reduce blood pressure, and also prevent oxidation of lipids.

Several clinical trials have shown that beta-carotene supplementation can induce remission of oral leukoplakia, a pre-cancerous lesion in the mouth. Beta-carotene has been found to increase cell to cell communication. In some cases this can increase the risk of cancer. Studies show smokers and heavy drinkers actually have an increased risk of lung cancer if they take beta-carotene supplements. The good news is that eating foods high in beta-carotene doesn't have the same effect as taking a supplement. Studies also show beta-carotene supplements may reduce the effect of cancer therapies.

Alpha and beta carotene are fat soluble, so they need to be eaten with some fat, at least 3-5 grams, in order to be absorbed. Cooking vegetables also increases the availability of these phytonutrients. Good plants sources include mango, apricot, sweet potatoes, carrots, kale, broccoli, spinach, turnip greens, winter squash and collard greens. The yellow color in milk fat, butter and egg yolk comes from carotenes. It's best to get your Vitamin A through these sources rather than taking beta-carotene supplements, because of the risks with supplements mentioned above. If you eat too much carotene, you can get carotenodermia, a yellowish discoloration of the skin that is harmless.

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