Carotenoids are fat-soluble chemicals that protect plants and give them their color. They are invaluable to human nutrition, many of them providing antioxidant benefits and others serving as the basis for vitamin synthesis by your body. Over 700 carotenoids have been identified in two categories -- carotenes and xanthophylls.
Carotenes and Vitamin A
Your body can make vitamin A from three carotenes -- alpha-carotene, beta-carotene and beta-cryptoxanthin. Your body needs vitamin A for growth, a healthy immune system, healthy skin and mucus membranes, good vision, strong bones and wound healing. It is also necessary for fetal development. Vitamin A supplements in amounts higher than 10,000 IU can be dangerous. Instead, give your body the materials it needs to make vitamin A by eating a variety of vegetables containing alpha-carotene, beta-carotene and beta-cryptoxanthin.
Vegetable Sources of Carotenes
Good vegetable sources of alpha-carotene are pumpkin, winter squash, collards, carrots and carrot juice. Those vegetables also contain beta-carotene. In addition, beta-carotene is found in spinach, sweet potatoes, kale, turnip greens, dandelion greens and cantaloupes. The best sources of beta-cryptoxanthin are pumpkin and raw papayas, with lesser amounts found in sweet red peppers, carrots, sweet yellow corn, fresh orange juice and oranges, watermelon, tangerines and nectarines. Cooking seems to enhance the benefits of most carotenes, although it sometimes destroys other nutrients.
Xanthophylls
Lutein is a carotenoid in the xanthophyll category. Your body does not use it to make vitamin A like it does with some carotenes. Lutein, along with another xanthophyll called zeaxanthin, are found in the lens and retina of your eye. Both xanthophylls absorb blue light in the eye, keeping it from reaching parts where the rays can do the most damage. This may be the reason a diet rich in foods containing lutein and zeaxanthin can help slow the development of age-related macular degeneration and cataracts. Supplements do not provide the same benefits.
Vegetable Sources of Lutein
Excellent vegetable sources of lutein and its partner in eye health, zeaxanthin, are spinach, kale, turnip greens and collards. Good sources include dandelion greens and mustard greens. Other vegetable sources are summer and winter squash, peas, pumpkin, brussel sprouts, broccoli and sweet yellow corn. As you can see, many of these vegetables are also good sources of carotenes.
Conclusion
You can't go wrong eating colorful vegetables. The USDA's My Pyramid recommends 2 to 3 cups of vegetables for adults daily. consume a variety of green, yellow, orange and red vegetables to ensure you get plenty of carotenes and lutein, as well as dietary fiber and other vitamins and minerals found in these nutritional powerhouses.
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