Cataracts and age-related macular degeneration (AMD) are the leading causes of visual impairment and acquired blindness in the U.S, affecting millions of aging Americans. Nutrition is one promising way to prevent or delay the progression of these diseases.
Two carotenoids, lutein (pronounced loo-teen) and zeaxanthin (pronounced zee-uh-zan-thin), are antioxidants that are located in the eye. Green leafy vegetables, as well as other foods such as eggs, contain these important nutrients. Many studies have shown that lutein and zeaxanthin reduce the risk of chronic eye diseases, including AMD and cataracts.
Lutein and zeaxanthin filter harmful high-energy blue wavelengths of light and help protect and maintain healthy cells in the eyes. Of the 600 carotenoids found in nature, only these two are deposited in high quantities in the retina (macula) of the eye.
The amount of lutein and zeaxanthin in the macular region of the retina is measured as macular pigment optical density (MPOD). Recently, MPOD has become a useful biomarker for predicting disease and visual function.
Unfortunately, the human body does not naturally make the lutein and zeaxanthin it needs. This is why eating green vegetables is important. Getting daily amounts of lutein and zeaxanthin through your diet or nutritional supplements can help maintain good eye health.
The crystalline lens (the natural lens in the eye) primarily collects and focuses light on the retina. To do this throughout your life, the lens must remain clear. Oxidation of the lens is a major cause of cataracts, which cloud the lens.
Antioxidant nutrients neutralize free radicals (unstable molecules) that are associated with oxidative stress and retinal damage. This is why the antioxidants lutein and zeaxanthin likely play a role in preventing cataracts. In fact, a recent study demonstrated that higher dietary intake of lutein and zeaxanthin and vitamin E was associated with a significantly decreased risk of cataract formation.
There is a lot of evidence that lutein and zeaxanthin reduce the risk of AMD. In fact, in the Age-Related Eye Disease Studies (AREDS and AREDS2), the National Eye Institute found that taking certain nutritional supplements every day reduces the risk of developing late AMD. Beyond reducing the risk of eye disease, separate studies have shown that lutein and zeaxanthin improve visual performance in AMD patients, cataract patients and people in good health.
If you are not getting enough lutein and zeaxanthin through your diet alone, consider taking daily supplements. Although there is no recommended daily intake for lutein and zeaxanthin, most recent studies show health benefits in taking 10 mg/day of a lutein supplement and 2 mg/day of a zeaxanthin supplement. .
Most Western diets are low in lutein and zeaxanthin, which can be found in spinach, corn, broccoli and eggs. The USDA Nutrient Database offers comprehensive information on raw and prepared foods.
*At this time, the AOA is unaware of any studies that have examined interactions between medications and lutein and zeaxanthin. The AOA also is not aware of any adverse health reports from interactions between medications and lutein and zeaxanthin. However, the AOA recommends consulting with a health care professional before beginning any supplementation regiment.