The most common cause of blindness among the elderly age-related macular degeneration may be averted or further deterioration halted by eating foods rich in antioxidants, according to a study by Brigham Young University and Cornell University.
The research, online now and scheduled to be published Friday in the Journal of Biological Chemistry, shows that two processes which each damage vision are almost exponentially more destructive when found together. But eating antioxidant-packed foods such as blueberries, asparagus, artichokes and almonds can disrupt the process.
It won't bring back vision that has been lost but can prevent further damage, according to Heidi Vollmer-Snarr, a chemist and assistant professor at BYU who has been investigating macular degeneration since her post-doctoral days at Columbia University.
An estimated 1.75 million elderly Americans have age-related macular degeneration, which typically leads to loss of central vision. That donut hole of missing sight can widen to destroy peripheral vision as well.
Cellular energy is stored in mitochondria, but over time, oxidation damages it. A vitamin A derivative, called A2E, also causes oxidative damage. Vollmer-Snarr said that when you have both of these age-triggered processes going on, the increase in destruction is significant. The A2E breaks up the energy production in mitochondria, which in turn stops the daily cleaning and maintenance of retinal cells, leading to more A2E buildup and a new round of damage.
Using vision cells from rats, cows and humans, the researchers showed that antioxidants stopped the harm, although they didn't reverse it. That finding indicates that antioxidant-rich foods could be used as both a prevention for age-related macular degeneration and to halt the slide for those who have already developed the common eye disease, Vollmer-Snarr said.
In a BYU news release explaining the research, University of Utah Moran Eye Center's Dr. Paul Bernstein noted that the mechanisms of macular degeneration have not been well known. This research, he said, "suggests the possibility of interventions which could prove to be powerful ways to prevent or delay age-related macular degeneration."
For the research, the scientists used the vitamin E derivative called trolox.
Other studies also have shown the value of antioxidants against age-related macular degeneration. For instance, the carotenoid antioxidant compound lutein, also fat-soluble, acts in a similar fashion. The role of antioxidants vitamins E and C and zinc have been highlighted in a large, multiyear, multicenter clinical study.
This new research sheds light on the mechanism for macular degeneration and confirms that the vision loss is the result of the oxidative damage that happens in cells over time, Vollmer-Snarr said. Understanding that process offers targets for treatment.
She noted that eye cells are nonreplicating, and once they're damaged, they're damaged. That's one reason many researchers believe that stem cells offer the best hope for an actual reversal of damage or outright cure. But such therapies are in the future, and far from sure. In the meantime, she said, "eat foods rich in antioxidants."BYU graduate student Junping Gao was a co-author on the study. Joining as co-authors were Cornell medical researchers Silvia C. Finnemann, Cristofol Vives-Bauza, Monika Anand, Arash K. Shirazi, Jordi Magrane and Giovanni Manfredi.
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