Cataracts (Prevention)

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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

 

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Principal Proposed Treatments for Cataracts (Prevention)

Other Proposed Treatments for Cataracts (Prevention)

References

 

 

 

 

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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.

 

 

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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

 

 

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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.

 

 

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References

 

1. Hankinson SE, Stampfer MJ, Seddon JM, et al. Nutrient intake and

cataract extraction in women: a prospective study. BMJ. 1992;305:335–

339.

 

2. Tavani A, Negri E, La Vecchia C. Food and nutrient intake and

risk of cataract. Ann Epidemiol. 1996;6:41–46.

 

3. Carson C, Lee S, De Paola C, et al. Antioxidant intake and

cataract in the Melbourne Visual Impairment Project [abstract]. Am J

Epidemiol. 1994;139(11 suppl):A65.

 

4. Robertson JM, Donner AP, Trevithick JR. Vitamin E intake and risk

of cataracts in humans. Ann N Y Acad Sci. 1989;570:372–382.

 

5. Rouhiainen P, Rouhiainen H, Salonen JT. Association between low

plasma vitamin E concentration and progression of early cortical

lens opacities. Am J Epidemiol. 1996;144:496–500.

 

6. Vitale S, West S, Hallfrish J, et al. Plasma antioxidants and

risk of cortical and nuclear cataract. Epidemiology. 1993;4:195–203.

 

7. Vitale S, West S, Hallfrisch J, et al. Plasma vitamin C, E, and

beta-carotene levels and risk of cataract. Invest Ophthalmol Vis

Sci. 1991;32:723.

 

8. Ross WM, Creighton MO, Trevithick JR. Radiation cataractogenesis

induced by neutron or gamma irradiation in the rat lens is reduced

by vitamin E. Scanning Microsc. 1990;4:641–650.

 

9. Mares-Perlman JA, Brady WE, Klein BEK, et al. Diet and nuclear

lens opacities. Am J Epidemiol. 1995;141:322–334.

 

10. Brown L, Rimm EB, Seddon JM, et al. A prospective study of

carotenoid intake and risk of cataract extraction in US men. Am J

Clin Nutr. 1999;70:517–521.

 

11. Chasan-Taber L, Willett WC, Weddon JM, et al. A prospective

study of carotenoid and vitamin A intakes and risk of cataract

extraction in US women. Am J Clin Nutr. 1999;70:509–516.

 

12. Age-Related Eye Disease Study Research Group. A randomized,

placebo-controlled, clinical trial of high-dose supplementation with

vitamins C and E and beta carotene for age-related cataract and

vision loss. AREDS Report No. 9. Arch Ophthalmol. 2001;119:1439–1452.

 

13. Teikari JM, Rautalahti M, Haukka J, et al. Incidence of cataract

operations in Finnish male smokers unaffected by alpha tocopherol or

beta carotene supplements. J Epidemiol Community Health. 1998;52:468–

472.

 

 

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