Principal investigator Silvia Finnemann of Fordham University in New York said the results from her study suggest age-related vision loss is a result of cumulative, oxidative damage over time.
"A lifelong diet enriched in natural antioxidants, such as those in grapes, appears to be directly beneficial for retinal pigment epithelium cells and retinal health and function," Finnemann said in a statement.
Age-related macular degeneration is a progressive eye condition, leading to the deterioration of the center of the retina -- the macula -- and it is the leading cause of blindness in the elderly.
Mice prone to developing retinal damage in old age in much the same way as humans do received a grape-enriched diet, a diet with added lutein, or a normal diet.
The study, published in Free Radical Biology and Medicine, found the grape-enriched diet protected against oxidative damage of the retina and prevented blindness in those mice consuming grapes. The lutein was also effective, but grapes were found to offer significantly more protection, Finnemann said.
Lutein -- found in dark green leafy vegetables and egg yolks -- is a carotenoid, not a vitamin, popular as a dietary supplement to help prevent macular degeneration or to help support healthy eyesight.
The study was funded by the California Table Grape Commission.