Conditions:
Cataracts (Prevention)

Principal Proposed Treatments
  • Antioxidants
Other Proposed Treatments
  • Bilberry, Ginkgo, OPCs (Oligomeric Proanthocyanidins), Turmeric, Cysteine, Lipoic Acid, Vitamin B3 (Niacin), Vitamin B2 (Riboflavin), Selenium, Taurine, Zinc

Cataracts—an opaque buildup of damaged proteins in the lens of the eye—are the leading cause of visual decline in those over 65. In fact, most people in that age group have at least the beginnings of cataract formation. Many factors contribute to the development of cataracts but damage by free radicals is believed to play a major role. (See the article on atherosclerosis for a description of free radicals.)

Cataracts can be removed surgically. Although this has become a relatively quick, safe, easy, and painless surgery, it does not result in completely normal vision. Clearly, preventing cataracts, if possible, would be preferable.

Principal Proposed Treatments for Cataracts (Prevention)

Antioxidants

Numerous observational studies suggest that high intake of antioxidants such as vitamin C, vitamin E, and carotenoids (beta-carotene, lutein, and lycopene) are associated with a reduced incidence of cataracts.^1–11

However, the results of observational studies are notoriously unreliable. It is quite possible that individuals who consume a diet rich in antioxidant vitamins have other lifestyle habits that could be responsible for the benefits seen. Furthermore, foods containing antioxidants also contain numerous other active substances, which could be responsible for the effects seen in some studies rather than the identified antioxidants themselves.

Studies that involve actually taking supplements (intervention trials) can provide much stronger evidence regarding whether a treatment actually works. Unfortunately, the results of a recent large intervention trial were not encouraging.

This double-blind placebo-controlled trial studied the effects of antioxidant supplements in 4,629 older individuals.¹² Participants received either placebo or an antioxidant supplement containing 500 mg of vitamin C, 400 IU of vitamin E, and 15 mg of beta-carotene. The results over more than 6 years showed no effect on the risk of development of cataracts nor the rate at which existing cataracts grew worse.

A previous double-blind placebo-controlled study examined the use of beta-carotene or vitamin E alone and failed to find them effective.¹³  

Other Proposed Treatments for Cataracts (Prevention)

Herbs high in antioxidant flavonoids are frequently suggested for preventing cataracts. These include bilberry, ginkgo, OPCs, and turmeric. For various theoretical reasons, the supplements cysteine, lipoic acid, niacin (vitamin B₃), riboflavin (vitamin B₂), selenium, taurine, and zinc have also been proposed. However, there is little real evidence that any of these treatments actually help.

Last reviewed March 2002 by Medical Review Board

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