Vision Information - Eyes and Nutrition
Many optometrists are looking beyond strict optometric and allopathic treatment by expanding their traditional roles to include other areas that affect eye health, such as nutrition. Clinical tests have revealed that nutrition can influence the development of cataracts and age-related macular degeneration (AMD), which are the two major causes of blindness and visual impairment in millions of aging Americans. Nutrition now plays a significant role because treatment options after diagnosis for these eye diseases is limited.
Age-related Eye Disease and Antioxidants
The leading cause of visual impairment and blindness in America are cataracts and age-related macular degeneration or AMD. These are highlighted by disturbing statistics:
Ways need to be found to delay this progression, and nutrition is proving to be one promising way of protecting the eyes from these diseases.
Antioxidants and AMD
The National Eye Institute undertook an Age-Related Eye Disease study in a large clinical trial testing the effect of a high dose antioxidant vitamin combination plus zinc on preventing or delaying the progression of AMD and its associated vision loss.
The study revealed that antioxidant vitamins and zinc supplements reduced the risk of developing advanced AMD by about 25 percent. The supplements also reduced vision loss by 19 percent in the same high-risk group that were tested.
The most effective supplement combination tested was:
Antioxidants and Cataracts
The Nutrition and Vision Project revealed that higher doses of vitamin C led to a reduced risk for cortical and nuclear cataracts. Results further revealed that people who used vitamins C and E supplements for more than ten years had slowed progression of nuclear cataracts.
A Second National Health and Nutrition Examination Survey found that higher levels of vitamin C in the diet were associated with a lower cataract risk.
The Nurses' Health Study revealed that the need for cataract surgery was lower among women who used vitamin C supplements for ten years or longer.
In the five-year follow-up to the Beaver Dam Eye Study a reduced risk of nuclear and cortical cataracts was revealed among people using multivitamins or any supplement containing vitamins C and E.
Lutein and Zeaxanthin
Lutein and zeaxanthin are carotenoids - antioxidants located in the eye which may protect against cataracts and AMD.
The Eye Disease Case Control Study revealed a significantly lower risk for developing AMD in people with high amounts of lutein and zeaxanthin in their blood. And dietary studies confirmed the association between frequent consumption of spinach or collard greens (particularly good sources of lutein and zeaxanthin) and lower risk AMD.
A national dietary study called the Third National Health and Nutrition Examination Survey found that consuming 6 mg per day of lutein and zeaxanthin was associated with reduced risk for developing AMD.
The intake of lutein and zeaxanthin has also shown a positive effect in reducing the need for cataract surgery.
The Nurses' Health Study revealed that consuming high amounts of these carotenoids (6 mg per day) lowered the need for cataract surgery. The Health Professional's Follow-Up Study produced similar results.
An interesting study of 372 men and women in England revealed that the risk for specific types of cataracts was lowest in people with the highest amount of lutein in their blood.
Natural Sources of Lutein and Zeaxanthin
Five servings of fruits and vegetables per day can provide about 5 to 6 mg of lutein and zeaxanthin. Dark green leafy vegetables are the primary source of lutein and zeaxanthin, but they can also be found in lesser amounts in broccoli, orange peppers, corn, peas, persimmons and tangerines.
If you find it difficult to increase the amount of fruits and vegetables in your diet, multivitamin/mineral and eye health supplements containing lutein and zeaxanthin are available.
The above studies reveal an obvious correlation between increased vitamin intake and eye disease.
Artificial supplementation in the form of tablets and capsules is recommended for convenience but a diet consisting of fresh fruits, vegetables and nuts will contribute not only to eye health but to overall physical well-being.