DHA, EPA, Low Glycemic Index Help in Macular Degeneration
They are linked to lower risk for progression to advanced disease regardless of supplementation
THURSDAY, June 25 (HealthDay News) -- Diets that contain more omega-3 fatty acids and have a lower glycemic index may help prevent progression to advanced age-related macular degeneration (AMD), according to research published online June 12 in the British Journal of Ophthalmology.
C-J Chiu, Ph.D., of Tufts University in Boston, and colleagues analyzed data from 2,924 participants in the Age-Related Eye Disease Study (AREDS), in which subjects were randomized to receive antioxidants; zinc and copper; antioxidants plus zinc; or placebo. Subjects filled out a food frequency questionnaire at baseline and underwent stereoscopic fundus photographs of the macula regularly over the eight-year trial period.
The researchers found that the greater intakes of docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA), and a lower dietary glycemic index, were linked to a lower risk for progression to advanced AMD, independent of the type of supplementation. For each of the omega-3s, those in the highest quartile range of intake had roughly 25 percent decreased risk. To prevent early disease progression, only those in the placebo group showed a benefit from higher DHA intake.
"One may speculate that a diet rich in omega-3 fatty acids or omega-3 fatty acid supplementation, without the AREDS supplement, might be most protective against progression of early AMD if started at the earliest stages of AMD, while, when combined with the AREDS supplement, it might be most protective with regard to preventing progression to advanced AMD," the authors conclude.