Age related macular degeneration [AMD] is the leading cause of severe vision loss in people over the age of 50. It is a disease of the macula, the small part of the eye’s retina that is responsible for central vision. This condition affects both distance vision and close vision, making some activities, such as reading or threading a needle, or driving a car, very difficult or impossible. Many people with AMD have deposits under the retina called drusen. Drusen alone usually do not cause vision loss, but when they grow in size and number, there is an increased risk of developing advanced AMD. People at risk of developing advanced AMD have a large amount of drusen. Drusen can lead to the development of geographic atrophy [severe dry AMD] or the development of abnormal blood vessels growing beneath the macula [wet AMD]
How can vitamins and minerals affect AMD?
A scientific study called AREDS (Age-Related Eye Disease Study) has shown that some antioxidant vitamins and zinc may reduce the impact of AMD in some people. The study found that people with high risk characteristics [drusen and/or atrophy] for advanced macular degeneration, who followed a dietary supplement of vitamin C, E and beta-carotene, along with zinc, lowered the risk of the disease progressing to advanced stages by about 25%. The same treatment did not appear to achieve the same results among people without AMD or within the first stages of the disease.
The nutritional supplements used by AREDS that proved to be beneficial were:
- Vitamin C (500 mg)
- Vitamin E (400 IU)
- Beta-carotene (15 mg)
- Zinc oxide (80 mg)
- Copper oxide (12 mg, to prevent the loss of copper associated with zinc supplements)
The levels of antioxidants and zinc that were shown to be effective in slowing AMD’s progression cannot be consumed through your diet alone. These vitamins and minerals are recommended in specific daily amounts as supplements to a healthy, balanced diet. Some people may prefer not to take high dosages of antioxidants or zinc for medical reasons. The AREDS study did not reveal any evidence that the treatment may be toxic. However, beta-carotene may increase the risk of developing lung cancer among smokers, or those who have recently quit smoking. Other studies have shown that eating dark, leafy greens, yellow, orange and other colorful fruits and vegetables, rich in lutein and zeaxanthin, may reduce your risk for developing AMD.
The recently released AREDS 2 treatment trial results indicated that there is no increased beneficial effect to taking lutein, zeaxanthin and Omega 3 fatty acids in patients already eating a healthy diet. For those not eating a healthy, balanced diet the addition of these supplements did show a beneficial effect. It appears that eliminating Beta-carotene from the supplement did not reduce the beneficial effects of the formulation. This is an important finding as Beta-carotene increases the risk of lung cancer in smokers.
The recommended dosages of these additional supplements are as follows:
- Lutein 10mg
- zeaxanthin 2mg
- Omega-3 fatty acids 1,000mg
Should I take anti-oxidant vitamins for AMD?
It is very important to remember that vitamin supplements are not a cure for AMD, nor will they restore vision you may have already lost from the disease. However, specific amounts of certain supplements do play a key role in helping some people at high risk for advanced AMD to maintain their vision. Talk to Dr. Comaratta to determine if you are at risk for developing advanced AMD, and to learn if supplements are recommended for you.
Can I Take a Daily Multivitamin if I Am Taking the AREDS Formulation?
Yes. A daily multivitamin contains many important nutrients not found in the AREDS formulation. For example, elderly people with osteoporosis need to be particularly concerned about taking vitamin D, which is not in the AREDS formulation. The AREDS formulation is not a substitute for a multivitamin. In the Age-Related Eye Disease Study, two-thirds of the study participants took multivitamins along with the AREDS formulation.
If you are already taking daily multivitamins and your doctor suggests you take the AREDS formulation, be sure to review all your vitamins with your doctor before you begin.
Can a Daily Multivitamin Alone Provide the Same High Levels of Antioxidants and Zinc as the AREDS Formulation?
No. The AREDS formulation’s levels of antioxidants and zinc are considerably higher than the amounts in any daily multivitamin.
Can Diet Alone Provide the Same High Levels of Antioxidants and Zinc as the AREDS Formulation?
No. The high levels of vitamins and minerals are difficult to achieve from diet alone. However, previous studies have suggested that people who have diets rich in green, leafy vegetables have a lower risk of developing AMD.
Will Taking the AREDS Formulation Prevent me from Developing AMD?
No. There is no known treatment that can prevent the development of AMD. The study did not show that the AREDS formulation prevented people from developing early signs of AMD. No recommendation has been made for taking the AREDS formulation to prevent early AMD.
Taking the formulation reduced the rate of advanced AMD in people at high risk by about 25 percent over a 6-year period. We do not know if this treatment effect will persist over a longer period. However, by continuing to follow the AREDS participants, we hope to find out if the treatment effect will last longer than six years.