CataractsCataracts develop when the proteins in the lens of the eye are damaged, causing them to become translucent or opaque. There are three types of major cataracts, depending on the location in the lens: nuclear, cortical and posterior subcapsular. There are several factors that we cannot control that may increase the risk of developing cataracts. These include: age, family history and ethnicity (African Americans have a higher risk for developing and becoming blind from cataracts). Some studies also suggest that women may be at a slightly higher risk than men. Research also shows that there are several risk factors for cataracts that we can control by changing certain behaviors. These preventive actions include: not smoking, reducing exposure to sunlight by wearing UVA/UVB protective eyewear and wide brimmed hats, controlling other diseases such as diabetes and eating a healthy diet.
Nutrition LinkSeveral research studies show that the antioxidant properties of vitamins C and E may protect against the development and progression of cataracts. Early evidence also suggests that the carotenoids lutein (pronounced loo-teen) and zeaxanthin (pronounced zee-uh-zan-thin), which are also antioxidants, may also be protective against cataracts.
Research – Antioxidant VitaminsSome recent studies compared diet and supplement intake of the antioxidant vitamins C and E with the development of cataracts. Many of these studies have shown that these antioxidants may decrease the development or progression of this disease. Some of the results are listed below:
- The Nutrition and Vision Project found that higher intakes of vitamin C led to a reduced risk for cortical and nuclear cataracts. Results also showed that people who used vitamin C and E supplements for more than ten years had decreased progression of nuclear cataracts.
- A recent analysis of results from a national dietary study (Second National Health and Nutrition Examination Survey) found that higher levels of vitamin C in the diet were associated with lower risk of cataracts.
- In the Nurses’ Health Study, the need for cataract surgery was lower among women who used vitamin C supplements for ten years or longer.
- The Roche European American Cataract Trial found that an antioxidant supplement with vitamins C and E and beta-carotene lead to a small decrease in the progression of cataracts in less than 3 years.
- In the Longitudinal Study of Cataract, vitamin E supplement use for at least a year was associated with a reduced risk of nuclear cataracts becoming more severe.
- The five year follow-up to the Beaver Dam Eye Study showed a reduced isk for nuclear and cortical cataracts among people using multivitamins or any supplement containing vitamins C and E.
Research – Lutein and ZeaxanthinLutein and zeaxanthin are promising nutrients in the fight against cataracts. Lutein and zeaxanthin are the only carotenoids found in the lens. Several recent studies have examined these two nutrients and their relationship to reducing the risk of developing cataracts:
- The Nurses’ Health Study found that high amounts of lutein+zeaxanthin were associated with a reduced need for cataract surgery. On average, people had intakes around 6 milligrams (mg) of lutein+zeaxanthin each day.
- The Health Professional’s Follow-Up Study also found that eating foods with high amounts of lutein+zeaxanthin (6.9 mg per day) were correlated with a reduced need for cataract surgery.
- The five-year follow-up to the Beaver Dam Eye Study showed that people with the highest intakes of lutein+zeaxanthin had a significantly lower risk for developing new cataracts than those with the lowest intakes.
- A recent study in England found that people with the highest amount of lutein in their blood, resulting from regular consumption of good food sources of lutein, had the lowest risk for posterior subcapsular cataracts.