Here's a study out of the USDA Nutrition Research Center on Aging at Tufts University and paid for by the NIH (National Institutes of Health) and also included AREDS (Age Related Eye Disease Study) researchers showed that a diet of the ''low'' glycemic index along with certain nutrients i.e. omega-3 fatty acids, zinc, lutein, zeaxanthin and vitamin's C and E was best at protecting early and advanced AMD or Macular Degeneration.
First Study Of Combined Dietary Factors Finds Reduced AMD Risks - Science Daily