While you may have heard the old adage about carrots preventing weak eyesight, you may not realize that a whole host of other nutrients can also help preserve vision. Eating well and including certain vitamins and minerals in your diet can help protect your eyes from a variety of diseases.
Types of Diseases
In addition to general eye health benefits, eating well can also help prevent specific eye diseases, including diabetes, age-related macular degeneration, cataracts and night-vision loss. Xeropthalmia, one of the leading causes of blindness in children in developing countries, results from drying out of the cornea and conjunctiva from a lack of vitamin A in the diet, The Merck Manuals Online Medical Library says.
Specific Vitamins
Eating dark green leafy vegetables and brightly colored vegetables such as carrots, squash, pumpkin and papaya supplies an adequate amount of vitamin A, which helps prevent both xeropthalmia and night blindness. Meat, liver, fish oil and egg yolks also help supply vitamin A, which is best absorbed when consumed with fats, Merck Manuals report. Carotenoids, foods that contain red, yellow or orange pigment, supply around 50 percent of dietary vitamin A for Americans, Medline Plus reports. Foods that contain beta-carotene, a type of red, yellow or orange carotenoid, include fruits, vegetables and whole grains. Carotenoids may help prevent cataracts, although this has not been adequately established, MedlinePlus says.
Lutein and zeaxanthin, carotenoids found in green and yellow vegetables, may help filter out damaging sunlight from the eyes, preventing retinal damage, the Ohio State University Extension explains. Carotenoids are part of an ongoing study to assess their effectiveness in reducing age-related macular degeneration, or AMD. Vitamin C, found in fruits, green vegetables, tomatoes and potatoes, may help reduce the risk of cataracts and glaucoma, says Joanne Pompano of the Yale-New Haven Teacher Institute.
Diabetic Benefits
While everyone with potential eye disease benefits from certain nutrients, diabetics in particular benefit from an overall healthy diet. Diabetics often experience eye damage that can lead to permanent vision loss. Keeping blood glucose levels low reduces the risk of diabetic retinopathy and other diabetes-related eye damage. Reducing glucose levels means following a diet low in refined sugars and choosing whole grains, vegetables and fruits instead.
Risks
High dietary intake of vitamins and minerals that prevent eye disease can cause harm in some cases. Ingesting very large amounts of vitamin A can cause toxicity. Headache, rash, increased intracranial pressure, nausea, vomiting and drowsiness can occur, the Merck Manuals warn. High dietary intake of carotene can cause carotenemia, a yellowish tinge to the skin.
Considerations
Many of the foods that benefit your eyes also benefit your general health. The American Heart Association and the American Diabetes Association endorse dietary guidelines that stress whole grains, fruits and vegetables as part of a healthy diet. Following these guidelines will also supply benefits for your eyes.
References
- Yale-New Haven Teachers Institute: Healthy Diet, Healthy Eyes
- Ohio State University Extension: The Eyes Have It--Balanced Diet is Key
- North Dakota State University Extension: Diabetic Retinopathy--Prevention, Treatment and Diet
- Merck Manuals Online Medical Library: Vitamin A Deficiency
- American Diabetes Association: What Can I Eat?
- American Heart Association: Healthy Diet Goals
