Articles about Eye Health and Disease 2001
 

AREDS Results: No Beneficial Effects Found with Antioxidant and Zinc Supplements in the Development of Cataract.

(From the Age-Related Disease Study Research Group. Arch Ophthal 2001;119:1439-1452.)

Cataract is a common cause of curable visual loss in older individuals of all ethnic backgrounds. The natural lens in the eye becomes progressively more cloudy, leading to blurred vision and visual side effects such as glare. Cataract extraction with lens implant is one of the most commonly performed surgical procedure in the United States. 

(For more information about cataract and cataract extraction, go to: Cataract.)

Previous experimental and observational data have suggested that antioxidants might reduce the development of age-related cataract.  In the AREDS (Age-Related Eye Disease Study Research Group) study, 4757 individuals ranging in age from 55 to 80 years were selected to take dietary supplements consisting of:

• Antioxidants (500mg vitamin C, 400 IU vitamin E, 15 mg beta carotene)

• 80 mg zinc, as zinc oxide, and 2mg copper, as cupric oxide

• Both antioxidants plus zinc together

• or Placebo

These individuals were enrolled in the Age-related Macular Degeneration part of the study, and observations were made during an average time span of 6.3 years in the study to see if the development of cataract reduced with antioxidant use.

Of the 4757 participants, 4629 had at least one natural lens present at the beginning of the study (cataract extraction may have already been performed). 96% of the participants were Caucasian, 56% were female, 8% smoked tobacco, and 66% chose to also take Centrum in addition to the study supplement.

Results: No statistically significant protection was seen in the development or progression of cataract during the study period when antioxidants were used. In all study groups (antioxidant supplement, zinc supplement, antioxidant and zinc together, and placebo) the chance of worsening cataract was 30% in 5 years. When different types of cataracts were analyzed, there was still no difference between the placebo and treatment groups in developing nuclear cataracts, cortical cataracts, and posterior subcapsular cataracts. Equal numbers in the groups required cataract extraction during the study period.

 

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