Can You Prevent Age-Related Macular Degeneration?
Although the causes of age-related macular degeneration (AMD) are not yet clearly understood, a combination of genetic and environmental influences are thought to contribute to the disease. While some risk factors can't be controlled, such as age and genetic makeup, there are some measures you can take to lessen your chances of developing AMD. Other risk factors include cigarette smoking and poor diet.
Age-Related Eye Disease Studies - AREDS and AREDS2
In 2001, the National Eye Institute (NEI) completed the Age-Related Eye Disease Study (AREDS) and found that a high potency combination of antioxidants and zinc reduced the risk of
advanced age-related macular degeneration (AMD) by 25 percent. This formulation contained:
- Vitamin C – 500 milligrams
- Vitamin E – 400 International Units (IU)
- Beta carotene – 15 milligrams (25,000 IU) – not recommended for smokers
- Zinc – 80 milligrams and Copper – 2 milligrams (must be included when taking zinc)
In 2006, the same research group at NEI launched a second large study called AREDS2 to learn if they could improve the AREDS formulation by adding omega-3 fatty acids and replacing beta carotene with two antioxidants, lutein and zeaxanthin.
Both AREDS and AREDS2 were carried out in clinical centers throughout the United States. In Portland, the research was a joint effort between the Devers Eye Institute and the Casey Eye Institute.
What are lutein, zeaxanthin and beta carotene?
These pigmented compounds belong to a family of nutrients known as carotenoids. Carotenoids are made by plants and found in green, yellow and orange fruits and vegetables. Although our bodies are unable to make lutein and zeaxanthin, they are highly concentrated in the macula of healthy retinas. In past studies, researchers found that the diets of some patients with AMD were lacking in lutein and zeaxanthin.
In the body, beta carotene is used to make Vitamin A, which is required by the retina to detect light and convert it into electrical signals. Beta carotene is not found in the eye. In contrast, lutein and zeaxanthin are found in the retina and lens, where they may act as natural antioxidants and help absorb damaging, high-energy blue and ultraviolet light.
What are omega-3 fatty acids?
Omega-3 fatty acids are found in cold-water fish, such as salmon and tuna, and included in fish oil supplements. Previous research suggested they may help protect against AMD.
What were the results of AREDS2?
The following are key results of the AREDS2 trial, published online May 5, 2013 in the Journal of the American Medical Association:
- Adding omega-3 fatty acids or lutein/zeaxanthin had no overall effect on AMD.
- Adding lutein/zeaxanthin may help people with very low levels of lutein/zeaxanthin in their diet.
- There is a link between beta carotene use and increased lung cancer risk in smokers and former smokers.
- Removing beta carotene or zinc did not lessen its effectiveness.
What You Should Know about AREDS Supplements
- If you are at high risk of developing advanced AMD, consider taking AREDS supplements. You cannot obtain these helpful vitamins and minerals by just the foods you eat. These formulations may slow your progression to advanced AMD and help you keep your vision longer if you have intermediate AMD or advanced AMD in one eye. The participants in the first AREDS trial were followed for 10 years, and the benefits of the AREDS formulation have persisted over this time. Your eye doctor can verify if you are at increased risk for developing advanced AMD.
- The supplements are not helpful if you have early AMD or healthy eyes. However, be sure to have your eyes checked every year to make sure your AMD isn't getting worse. Your eye doctor can tell you what stage you are in.
- Check with your eye doctor about which format is best for you. The AREDS supplements are available without a prescription in pharmacies and other stores that sell dietary supplements. You also can purchase the ingredients separately. For most cases, we recommend the AREDS2 formula that includes lutein, zeaxanthin, zinc, copper, vitamin C, and vitamin E.
The original AREDS study found few possible side effects from taking the dietary supplements. However, beta carotene is not recommended for smokers or those who have recently quit, as it may increase the risk of lung cancer. Currently, we do not recommend AREDS vitamin formulas that include beta carotene.
To learn more about AREDS2 and its results, visit www.areds2.org
Remember: See your eye doctor for a dilated eye exam and to find out if you are a candidate for the AREDS eye vitamins.
A Healthy Diet
Eating whole, natural foods is considered the safest and most effective way to obtain eye-healthy nutrients. Try to eat several servings a day of green leafy vegetables and other yellow, orange and green fruits and vegetables. For overall health, a diet low in cholesterol, saturated and trans fat, sugar and salt are recommended.