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Beta-carotene is a previtamin-A compound found in plants. The
body converts beta-carotene to vitamin A.
Q. How much vitamin A do you need ? You can get vitamin A from two types of food sources: animal products that contain vitamin A (such as liver or butter) or plant products that contain carotene, which your body converts into Vitamin A. Foods containing carotene are usually yellow/orange or leafy and green. The following is a sampling of foods with high vitamin A values:
The above values are for raw foods. Cooking can change the values, as heat will destroy vitamin A and beta-carotene in foods. Also, if you don't pick up fresh food, select frozen rather than canned, as canning strips away much more of the vitamin A in food.  Dr. Steven Cantrell and Dr. Rodney Ausich report that "there is strong clinical evidence that consumption of the carotenoids lutein and zeaxanthin can reduce a person's risk of ARMD (age-related macular degeneration)." They may also reduce the risk of cataracts. Lutein and zeaxanthin are closely related: they often appear together in fruits and vegetables, and your body can convert lutein into zeaxanthin. 
There is currently no RDA for either, but you need to get some every day, because your body can't make them. The best source of lutein and zeaxanthin is green, leafy vegetables, particularly spinach. Kale and collard greens are also good choices. You can also find lutein and zeaxanthin in yellow and orange fruits and vegetables, such as corn. By the way, the Lutein Information Bureau says that cooked vegetables are a better source of lutein than raw, as cooking breaks down the cell walls to release the lutein.  Vitamin A isn't the only antioxidant your eyes need (antioxidants take care of the free radicals that would otherwise damage your body, including your eyes). Another vision superhero is vitamin C. 
Studies suggest that high levels of vitamin C can reduce the risk of cataracts, which are caused by a buildup of protein that results in cloudy vision. Antioxidant vitamins C and E may also play a role in delaying age-related macular degeneration, which currently has no cure. As if potential cataracts or macular degeneration weren't reason enough to make sure you get your vitamin C, it may also prevent and alleviate glaucoma. Studies have shown it to reduce pressure in the eyes of glaucoma patients.
Q. How much vitamin C should you be getting? Citrus fruits, berries, peppers, tropical fruits, potatoes and green, leafy vegetables have a lot of vitamin C. Here's a sampling:
The above values are for raw foods. Cooking can change the values, as heat will decrease the vitamin C content. Light is also destructive to C, so if you drink orange juice, it's better to purchase it in opaque plastic jugs or cartons, rather than in glass bottles. Like vitamin A, foods with C are better fresh than frozen or canned, as either process could deplete the amount of the vitamin.  Evidence suggests that your eyes also need bioflavonoids, which are sometimes called vitamin P (though they aren't vitamins). They're compounds that give certain foods their color, and they often work as antioxidants. The good news is: almost any food that has vitamin C in it also has bioflavonoids, so there is no extra list of foods for you to eat. Plus, bioflavonoids help your body to absorb C. 
Bilberry is the source of bioflavonoids most often touted as being good for your eyes, but it's not very common in the United States. The white part in the center of citrus fruits is an excellent source of bioflavonoids, and you can also get them from red and purple fruits, such as cherries, grapes and plums. Buckwheat is another good source. You may sometimes hear bioflavonoids referred to by their many specific names, including: quercetin, rutin, hesperidin or the subgroup anthocyanosides.  The other key antioxidant vitamin that your eyes require is vitamin E. Many studies suggest that E helps to prevent Cataracts, and it might be yet another factor in preventing macular degeneration. 
Q. How much vitamin E do you need? Nuts are your best source of vitamin E. Here's a sampling of foods that are high in E:
Finally, bear in mind that all antioxidants are good for your body, including your eyes, but vitamins A, C and E and lutein are the most helpful to your eyes. You can use some minerals as well. Selenium, for example, both helps your body to absorb vitamin E and helps it to make its own antioxidants. Brazil nuts, yeast and seafood (like oysters) contain good amounts of selenium. Zinc helps your body to absorb vitamin A and is also part of an enzyme in your body that reduces the number of free radicals. Zinc might also protect against macular degeneration and Night Blindness. You can get zinc from oysters, hamburgers, wheat and nuts. That's certainly a lot of information to remember. It's far easier to just make sure you eat plenty of green, leafy vegetables, throwing in some nuts and yellow or orange fruits and vegetables for variety. Source(s): Above information & images are taken from All About Vision and Thrive Online. Sunflower image © Roma Stock. All rights reserved of the respective oweners. For our full credit and copyright information please view our Credit List. Disclaimer: Any information displayed here is just for educational purposes, and may not be taken as an expert advice and should not be applied in life without consulting your eye doctor/specialist. We here by take no responsiblity of the accuracy of the above content as they have been taken from various sources. |
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Did you know ?
A cataract needs to be removed only when vision loss interferes with your everyday activities, such as driving, reading, or watching TV. [submit fact] |