Antioxidents & Age-Related Eye Disease

Cataracts and age-related macular degeneration (AMD) are the leading causes of visual impairment and acquired blindness in the U.S., and are key quality of life issues among millions of aging Americans. Both the severity and irreversibility of cataracts and AMD have generated interest in ways to either prevent or delay their progression. Nutrition is one promising means of protecting the eyes from these diseases.

Research - Antioxidants and AMD

The Age-Related Eye Disease Study from the National Eye Institute (NEI) is the first large clinical trial to test the effect of a high dose antioxidant vitamin combination plus zinc on preventing or delaying the progression of AMD and its associated vision loss.

The antioxidant vitamins and zinc supplement reduced the risk of developing advanced AMD by about 25 percent in the study subjects who were at high risk for developing the advanced stage of this disease. In the same high-risk group, the supplements also reduced vision loss by 19 percent.

The doses tested were: According to researchers, this supplement combination is the first effective treatment to slow the progression of AMD. The NEI concluded that persons older than 55, with signs of intermediate to late vision loss due to AMD, should consider taking a supplement such as that used in this trial. Effective treatment can delay progression to advanced AMD in about 300,000 people who are at high risk.

Research - Antioxidants and Cataracts

Some recent studies compared dietary and supplemental intake of antioxidant vitamins with development of cataracts. Many of these studies have shown that antioxidant vitamins may decrease the development or progression of this disease. Some of the results are listed below:

What You Need to Know

Given the positive association between nutrition and cataracts and AMD, it seems prudent for people to increase the amount of certain antioxidants in the diet. Eating five servings of fruits and vegetables each day as currently recommended by the National Cancer Institute and U.S. Department of Agriculture can provide more than 100 mg vitamin C, given wise choices of fruits and vegetables. Eating two servings of nuts and seeds can provide 8-14 mg vitamin E (11.9-20.8 IU) (see tables for good food sources of these nutrients).

However, the majority of people in the U.S. are not eating five servings of fruits and vegetables and good food sources of vitamin E each day. The average daily diet contains approximately 100 mg vitamin C and 9 mg vitamin E (or 12 IU). In the studies referenced here, levels associated with a benefit were considerably higher than the current average intake. If you find it difficult to increase the level of these antioxidants in your diet, multivitamin/mineral and eye health supplements containing these antioxidants are available.

Nutrient Values Tested

Recommended Dietary Allowance (RDA) 1,2
Levels Associated with Health Benefit
Percent of People Getting Less than 100% of RDA 1,2,3,4
Vitamin C
90mg for men
75mg for women
+35mg for smokers
SYMBOL 250mg
More than 50% of individuals
Vitamin E*
22 IU (15 mg) natural
33 IU (30 mg) synthetic
More than 90% of indivicuals

* The Food and Nutrition Board reported two different RDA values for vitamin E depending on synthetic or natural source.
  1. Dietary Reference Intakes for Vitamin C, Vitamin E and Carotenoids. Institute of Medicine, 2000.
  2. Dietary Reference Intakes for Vitamin A and Zinc. Institute of Medicine, 2001.
  3. Vitamin and mineral data was obtained from CSFII, 1994-1996. Values correspond to all individuals.
  4. Carotenoid data was gathered from NHANES III, 1988-1994.

Food Sources

Most fruits and vegetables are excellent sources of vitamin C, including oranges, grapefruit, strawberries and papaya, as well as green peppers and tomatoes.

Vitamin E is more difficult to obtain from food sources alone since it is found in very small quantities in foods, such as vegetable oils, nuts and seeds. Good food sources include vegetable oils (including safflower and corn oil), almonds, pecans, wheat germ and sunflower seeds.

Good Food Sources of Vitamin C (mg/serving)

Vitamin C
Orange juice, fresh squeezed
1 cup
Grapefruit juice, fresh squeezed
1 cup
1/2 medium
1/4 melon
1 medium
Green peppers, raw chopped
1/2 cup
Tomato juice
1 cup
1/2 cup
Broccoli, raw chopped
1/2 cup
1/2 medium

Source: USDA Nutrient Database for Standard Reference Release 13

Good Food Sources of Vitamin E (mg/serving)

Vitamin E
1/4 cup
9.3 (13.9 IU)
Sunflower seeds
1/4 cup
5.8 (8.7 IU)
Safflower oil
1 tbsp
4.7 (7.0 IU)
1/4 cup
3.3 (4.9 IU)
Peanut butter
2 tbsp
3.2 (4.8 IU)
Corn oil
1 tbsp
2.8 (4.2 IU)

Source: USDA Nutrient Database for Standard Reference Release 13