Do You Get Enough Antioxidants For Your Eyes?

There are many antioxidants that work in your favor for eye-health. For example, vitamin A is a powerful antioxidant that is known primarily for its effect on the retina, especially that of improving night vision. The body converts vitamin A, found in animal tissues, to the fat-soluble compound retinol for storage in the liver. Once vitamin A is stored in the liver, zinc is needed to liberate it for transport to the eyes as needed. Vitamin A is found in fish, fish liver oil, eggs, and liver.

It is possible to use beta-carotene, one of a class of substances known as carotenoids, as a substitute for vitamin A, because beta-carotene is a precursor of vitamin A and is converted into retinol in the liver. Eye experts have found that taking supplemental vitamin A palmitate in combination with manganese has been helpful to some people with glaucoma.

Beta-carotene sources in food vary immensely. Sweet potatoes top the list; raw carrots follow. At the low end are apples. In between lie a host of fruits and vegetables, including purslane (best known as a common weed, but now also grown commercially for use in salads), butternut and hubbard squash, mangoes, dandelion greens, kale, turnip greens, beet greens, red pepper, papaya, cantaloupe, Swiss chard, fresh or dried apricots, bok-choy, mustard greens, collards, tomatoes (also sauces and juices), broccoli, nectarines, prunes, tangerines, asparagus, romaine lettuce, avocados, plantains. Also included are savoy cabbage, Brussels sprouts, green peas, peaches, oranges, and bananas.

In natural sources, you not only get beta-carotene, but all the carotenoids as well, plus a host of other compounds necessary for optimum health. People who have diabetes may lose their ability to convert beta-carotene to retinol, and so must take vitamin A in its fat-soluble form. Fat-soluble vitamin A is found in fish liver oil, eggs, and liver. Air pollution, nitrates, nitrites (commonly used in fertilizers), and cooking and canning destroy or weaken vitamin A's effectiveness.

The carotenoids, of which beta-carotene is only one, are gaining ground among natural ways of achieving eye health. In addition to beta-carotene, two carotenoids that relate directly to eye health are lutein, which is present in spinach, marigolds, sunflowers, and kale, and lycopene, which is found in tomatoes.

Lutein has received considerable attention, especially for the problem of macular degeneration. Studies suggest that a high intake of foods rich in lutein may protect the retina from oxidative damage leading to degeneration of the macula. Super foods include kale, spinach, collard greens, broccoli, Brussels sprouts, leaf lettuce, green peas, and summer squash.

Foods that contain a moderate amount of lutein include cabbage, marigold, carrots, corn, green beans, and tomatoes. Lutein is also available in supplement form, either by itself or as part of one of the eye therapy supplementations. However, lutein and beta-carotene should not be taken together at the same time because they compete for absorption in your gut. Therefore it is better to take your beta-carotene, say, at breakfast and your lutein with your dinner, especially if you're having a salad dressed with olive oil. Both lutein and beta-carotene are more readily absorbed with a bit of fat.