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 AREDS 2
In 2001, the National Eye Institute (NEI) completed the Age-Related Eye Disease Study (AREDS) and found that a high dose combination of antioxidants and zinc reduced the risk of advanced AMD by 25 percent.
In 2006, the same research group launched a second large study called AREDS 2 to learn if they could improve the AREDS formula by adding omega-3 fatty acids and replacing beta carotene with two antioxidants, lutein and zeaxanthin.
Both AREDS and AREDS 2 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 AREDS 2?
The following are key results of the AREDS 2 trial:
- Adding omega-3 fatty acids or lutein/zeaxanthin did not help or hurt.
- Adding lutein/zeaxanthin may help people with very low levels of lutein/zeaxanthin in their diet.
- Smokers and former smokers who took AREDS with beta-carotene had a higher incidence of lung cancer.
What You Should Know about AREDS 2 Supplements
- If you are at high risk of developing advanced AMD, consider taking AREDS 2 supplements. You cannot get these helpful vitamins and minerals by just the foods you eat. The supplements 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 supplements have persisted over time.
- The original study found few possible side effects from taking the dietary supplements. However, beta-carotene is not recommended for smokers or those who have frequently quit, as it may increase the risk of lung cancer.
- 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.
- Talk to your family doctor or eye doctor before starting the regimen, which has high levels of antioxidants and zinc. This is especially important if you are taking several medications for chronic diseases.
- The AREDS 2 supplements are available without a prescription in pharmacies and other stores that sell dietary supplements. You also can purchase the ingredients separately. Both smokers and non-smokers should take supplements that replace beta carotene with lutein. Supplements based on AREDS 2 contain the following daily servings:
- Vitamin C - 500 milligrams
- Vitamin E - 400 IU
- Zinc - 80 mg and Copper - 2 mg (must be included when taking zinc)
- Lutein - 10 mg
- Zeaxanthin - 2 mg
Remember: See your eye doctor for a dilated eye exam and to find out if you are a candidate for the AREDS 2 eye vitamins.
Learn more about AREDS 2
A Healthy Diet
Medical science has yet to identify specific foods that protect against AMD. However, new evidence is emerging that shows your eating habits may play a role. A recent large-scale study found that the traditional Western diet markedly increases your chances of early or advanced AMD, while a more heart-healthy diet is strongly associated with lower odds for early or advanced AMD. A traditional Western diet includes a higher intake of red meat, processed meat, high-fat dairy products, French fries, refined grains and eggs. A heart-healthy diet emphasizes vegetables, legumes, fruit, whole grains, tomatoes and seafood. The healthier diet also helps with other chronic diseases, such as diabetes, and is comparable to such heart-healthy eating plans as the Mediterranean Diet and DASH Eating Plan.
Learn more about the DASH Eating Plan.