Conditions:
Macular Degeneration

Principal Proposed Treatments
  • Zinc with or without Antioxidants (Prevention)
Other Proposed Treatments
  • Carotenoids, Bioflavonoids

The lens of the eye focuses an image of the world on a portion of the retina called the macula, the area of finest visual perception. After cataracts, damage to the macula is the second most common cause of visual impairment in those over 65. Smoking, high blood pressure, and atherosclerosis are associated with macular degeneration. Bright light also appears to play a role by creating damaging natural substances in the eye, called free radicals. Gradual deterioration of the macula is called macular degeneration.

In the most common form of macular degeneration, a substance known as lipofuscin accumulates in the lining of the retina. A much less common form of macular degeneration involves the abnormal growth of blood vessels. This can be treated very successfully, if attended to soon enough, but may lead to irreversible blindness if left untreated. For this reason, medical consultation in all cases of macular degeneration (or any other type of vision loss) is essential.

Principal Proposed Treatments for Macular Degeneration

Zinc and Antioxidants

Growing evidence suggests that a mixture of zinc and antioxidants can prevent or slow the progression of macular degeneration.

A double-blind placebo-controlled trial evaluated the effects of zinc with or without antioxidants on macular degeneration in 3,640 individuals in the early stage of the disease.¹ Participants were randomly assigned to receive one of the following treatments: antioxidants (vitamin C 500 mg, vitamin E 400 IU, and beta-carotene 15 mg), zinc (80 mg) and copper (2 mg), antioxidants plus zinc, or placebo. The results indicate that zinc alone or, even better, zinc plus antioxidants, significantly slowed the progression of the disease.

Note: Zinc at a dose of 80 mg daily can be harmful. One of the problems is that high-dose zinc supplementation impairs copper absorption. That's why extra copper was provided in the study described above. However, there may be other risks as well. Physician supervision is advised. For other dosage and safety issues, see the full zinc article.

Smaller studies of zinc for macular degeneration have found mixed results.^3,4

Other Proposed Treatments for Macular Degeneration

Observational studies suggest that higher intake of dietary carotenes is associated with a lower incidence of macular degeneration.^5,6 Carotenes (carotenoids) are a group of substances that are found in many fruits and vegetables, especially yellow-orange and dark green ones. Beta-carotene is the most famous carotene; however, in the absence of zinc supplements, beta-carotene (given along with vitamin E and vitamin C) does not appear to be helpful.¹⁵

The less well known carotenes lutein and zeaxanthin have also been investigated for a possible role in preventing macular degeneration.^7,8 These are principally found in dark green leafy vegetables, such as spinach and collard greens. It has been suggested that lutein may protect the macula from light-induced damage by dyeing it yellow, thereby acting as a kind of natural sunglasses. It also acts in the usual antioxidant fashion by neutralizing free radicals.⁹ However, one observational study found little evidence of benefit with either lutein or zeathanthin.¹⁰

Flavonoids are another group of naturally occurring chemicals, found in many plants, that may offer a variety of beneficial effects. Weak but interesting evidence suggests that the flavonoid-rich herbs bilberry, ginkgo, and OPCs may prevent or treat macular degeneration.^11,12,13

Moderate wine consumption might also help prevent macular degeneration.¹⁴ Like these herbs, wine contains high levels of flavonoids.

Last reviewed July 2002 by Medical Review Board

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