Cataracts are a leading cause of vision loss in the world, and age-related macular degeneration is the most common cause of vision loss for Americans 65 and older. Although treatments exist for the management of both conditions, health care providers and researchers have continued to look for other ways to treat these visually devastating diseases. Evidence has shown that changing dietary habits can lessen the risk for developing these conditions, says DiabetesSelfManagement.com.
Foods That Contain Vitamin C
Vitamin C is an antioxidant present in a variety of fruits and vegetables. This vitamin has been shown to decrease the risk of cataracts and, when taken with other nutrients, can help reduce the risk of progression to advanced macular degeneration, says the American Optometric Association. The Recommended Dietary Allowance, or RDA, is 90 milligrams per day for men and 75 milligrams per day for women, but the daily intake that has been shown to have an impact on disease development is at least 300 milligrams for cataracts and 500 milligrams for macular degeneration.
To increase your intake of vitamin C, boost your intake of citrus fruits. One 8 oz. cup of orange juice contains 124 mg of vitamin C, and a medium-size orange contains almost 70 mg. Vegetables also contain vitamin C; a raw tomato provides almost 16 mg and a cup of spinach has almost 18 mg. Other sources of vitamin C include peaches, bananas, grapefruit and apples. If you eat the suggested five to nine servings of fruits and vegetables each day, you might be able to achieve the recommended amount of the vitamin, says DiabetesSelfManagement.com. If you are unable to increase your intake of vitamin C to suggested levels, you might consider taking a vitamin supplement. You should discuss supplementation with your physician before you start.
Foods That Contain Vitamin E
Another vitamin that has been found to reduce the risk of both cataracts and macular degeneration is vitamin E, according to the American Optometric Association. This vitamin might protect vision cells from damage. Research has shown that 400 International Units, or IU, of vitamin E, when taken with other vitamins and minerals, can reduce the risk of advanced macular degeneration. The amount needed to lower the risk of cataract development is not fully known. The RDA for this nutrient is 22 IU for both men and women.
Foods high in vitamin E include nuts, sweet potatoes, peanut butter and fortified cereals. Almonds and sunflower seeds both contain 11 IU of vitamin E. Sweet potatoes contain 1.2 IU, and 2 tbsp. of peanut butter might contain up to 4 IU. Diets lower in fat tend also to be lower in vitamin E; vitamin E supplementation might be needed to reach the higher doses found in the studies. High levels of vitamin E can interfere with blood clotting, so before beginning supplementation, a physician should be consulted.
Lutein and Zeaxanthin
Lutein and zeaxanthin are carotenoids that have been found to protect cells in the eyes from harmful light and lower the risk of macular degeneration; a large study called the Age-Related Eye Disease Study, or AREDS2, is ongoing to better understand the effect of lutein and zeaxanthin on macular degeneration. Another study published in the "Archives of Ophthalmology" in 2008 found that higher dietary intakes of these carotenoids also reduced the risk of cataract development in women. No recommended daily amount has been determined for these substances, but 10 mg of lutein and 2 mg of zeaxanthin have been used in both studies.
Foods high in these substances include dark green leafy vegetables such as spinach, kale, and collard and turnip greens, according to the American Optometric Association. One cup of each of these leafy greens contains at least 12.2 mg of lutein and zeaxanthin. Other good sources include corn, green peas, broccoli, orange peppers and eggs. Including more leafy greens and other colorful vegetables can confer other benefits, but these foods are high in other nutrients and fiber. Supplementation is also available if needed.
Omega-3 Fatty Acids
Omega-3 fatty acids are important to the function of the body. Recent research has found that omega-3 may help fight the development of dry eye syndrome, cataracts, diabetic retinopathy and age-related macular degeneration, according to the American Optometric Association. The AREDS2 study is also looking at the importance of omega-3's in the prevention of macular degeneration. The amount of omega-3 needs to prevent or treat diseases is not fully known at this time.
Omega-3's are found in fatty fish such as salmon, tuna, trout, herring and mackerel; these fish contain large amounts of these fatty acids. For example, 3 oz. of cooked salmon contain 1,800 mg, and 3 oz. of tuna provide 1,300 mg. Other sources include walnuts, almonds and flaxseeds, as noted by DiabetesSelfManagement.com. Many foods are also being supplemented with omega-3 fatty acids such as milk, eggs and yogurt. Supplementation with fish oil can also provide these nutrients, but because high doses can interfere with blood clotting, you should discuss additional fish oil supplementation with your physician.
References
- "Archives of Ophthalmology"; "Dietary Carotenoids, Vitamins C and E, and Risk of Cataract in Women"; William Christen et al; 2008.
- American Optometric Association: Lutein and Zeaxanthin
- American Optometric Association: Vitamin C
- American Optometric Association: Vitamin E
- American Optometric Association: Essential Fatty Acids
