Question: Who is susceptible to macular degeneration and what causes it?
Age-related macular degeneration (AMD) affects Canadians over the age of 50 and the incidence is expected to increase by 50 per cent over the next two decades. It's a chronic disease that attacks the central part of the retina called the macula, which controls fine, detailed vision. The condition results in progressive loss of visual sharpness, making it difficult to drive a car, read a book or recognize faces.
It's thought to be caused by a number of factors such as genetics, family history, cigarette smoking, high blood pressure, excessive sunlight exposure, and a diet low in antioxidants.
Question: What did this new study find?
Inflammation is also thought to play a role in the development of AMD. One omega-3 fatty acid in fish, called DHA (docosahexaenoic acid), is concentrated in the retina where it's thought to prevent damage through its anti-inflammatory and antioxidant properties.
In the study, researchers investigated omega-3 fatty acid intake among 1,837 older adults with AMD. Those with the highest omega-3 fat intake - mainly from fish and seafood - were 30 per cent less likely to progress to advanced AMD over 12 years than their peers who consumed the least. Previous studies have linked higher intakes of fish with a lower risk of developing AMD.
I would recommend eating oily fish like salmon, trout or sardines twice per week. If you don't like fish, consider taking a fish oil capsule once or twice daily. If you're a vegetarian, DHA supplements made from algae are available.
Question: Which other foods may help prevent macular degeneration?
Nuts. Eating nuts has been linked to a lower risk of macular degeneration. Nuts, which have anti-inflammatory and antioxidant effects, may reduce the risk of cardiovascular disease and type 2 diabetes - diseases linked to AMD. Include 1 serving (1/4 cup) of nuts in your diet a few times each week.
Lutein-rich foods. This phytochemical, abundant in leafy greens, is concentrated in the macula where it protects from damaging UV light. A high intake of lutein from foods has been linked with a lower risk of AMD. The best sources of lutein are spinach, swiss chard, kale, collard greens, and rapini but you'll also find some in green peas, broccoli, Brussels sprouts, nectarines and oranges.
Low glycemic foods. Evidence hints that a diet based on refined (white) carbohydrates and sugary foods, or high glycemic foods, boosts the risk of early AMD. It's thought that these foods may contribute to inflammation and oxidative damage in the retina. Include low glycemic foods such as beans, lentils, nuts, pasta, brown rice, sweet potatoes, steel-cut or large flake oatmeal, oat bran, and bran cereals at meals. Other low glycemic foods include apples, oranges, peaches, pears, berries, yogurt, milk and soy beverages.
Question: Do supplements help?
To prevent getting AMD, the research shows that antioxidants from normal foods can help. However, people who have AMD should discuss antioxidant supplementation with their eye care doctor. A landmark study, called The Age-Related Eye Disease Study, found that a special high-dose antioxidant supplement with vitamin C, vitamin E, beta-carotene and zinc delayed the onset of advanced AMD by 25 per cent. The formula is sold under the brand name Vitalux (Novataris) in drug stores. Smokers with AMD should choose a beta-carotene free formula.
The AREDS formula is not intended for healthy people who don't have AMD. This supplement was shown only to benefit people with intermediate or advanced AMD. Researchers don't yet know if the formula is effective in people with early stages of the disease.
