The AREDS involved about 4,700 men and women aged 55 to 80. About 3,600 of them were diagnosed with borderline or early, intermediate, or advanced AMD in at least one eye and were followed for about six years for the AMD portion of the study. Those participants who took a supplement containing antioxidants and zinc were about 25% less likely to develop further AMD, compared to those who took a sugar pill. The supplements did not seem to have much effect on those who began the study with borderline or mild AMD, and did not affect the risk of cataract.
The seeming ability of supplements to stave off further progression of AMD is particularly noteworthy because, up to this point, there has been no treatment for most cases of AMD. While supplements did not reverse damage or restore vision already lost from AMD, they did appear to help stop or delay progression of the disease.
The supplement that showed promise contained 500 mg of vitamin C, 400 International Units of vitamin E, 15 mg of beta-carotene, 80 mg of zinc, and 2 mg of copper. Copper must be added to the supplement to prevent copper deficiency, which can occur with high zinc intake.
Note that this is a high-dose formulation whose long-term effects, if any, are unknown. High doses of beta-carotene, such as those found in this mix, may be harmful to smokers.
The people in this study who benefited were those who already had AMD (the study was not designed to test whether supplements can prevent AMD) and whose disease had already progressed to a certain point. In other words, these supplements are only appropriate for certain people, and anyone considering their use should discuss it with their doctor first.
There is no evidence of benefits from other supplements, such as a pill containing lutein and zeaxanthin. (Lutein and zeaxanthin were not included in the AREDS study.) The jury is still out as to whether substances such as lutein and zeaxanthin are truly helpful in reducing the risk of eye disease. All that is known right now is that there is an association between eating foods high in these compounds and reduced risk. Because most studies of lutein and zeaxanthin have involved food sources of these nutrients, it is difficult to say if a supplement of these carotenoids alone would be beneficial; other nutrients in these carotenoid-rich foods might also be necessary to have an effect.
What you can do
Safeguarding vision, then, can come down to some sensible — and familiar — behaviors. These include the following:
- Wear sunglasses that protect the eyes from both ultraviolet A and ultraviolet B rays.
- Keep blood glucose under control.
- Stop smoking or cut back as much as possible if you smoke.
- Eat five to nine servings of produce a day. Because carotenoids add color to produce, choose brightly and deeply colored fruits and vegetables as often as possible. Include leafy green vegetables in your meals several times a week.
- Include plenty of vitamin C in your diet by choosing several daily servings of foods such as cantaloupe, strawberries, citrus fruits, kiwifruit, mango, papaya, broccoli, Brussels sprouts, sweet peppers, tomatoes, cauliflower, potatoes, and, again, leafy greens.
- Eat fatty fish two or three times a week. Limit total fat and commercially processed baked goods and snack foods.
- Have an annual eye exam (unless your doctor advises a different schedule) that includes dilating the pupils.
The good news is that there is no need to wait for the latest research to begin eating for healthy eyes. Eating dark leafy greens or foods high in vitamin C as part of a diet rich in fruits and vegetables is advice virtually every health professional can back.