Dec. 1, 2010 -- New research indicates that diets rich in omega-3 fatty acids from fish and shellfish may be good for the eyes of older Americans, offering protection against age-related macular degeneration, a common cause of blindness in the U.S.
The findings are published in the December issue of Ophthalmology, the journal of the American Academy of Ophthalmology.
Researchers at the Wilmer Eye Institute at Johns Hopkins School of Medicine report that they’ve found that high concentrations of omega-3s in the eye’s retina may be essential for eye health.
“Our study corroborates earlier findings that eating omega-3 rich fish and shellfish may protect against [advanced age-related macular degeneration],” researcher Sheila K. West, PhD, part of the Salisbury Eye Evaluation study, says in a news release.
While participants in study groups averaged at least one serving of fish or shellfish a week, those who had advanced macular degeneration “were significantly less likely to consume high omega-3 fish and seafood,” she says.
The study examined whether dietary zinc from crab and oyster consumption had an impact on advanced macular degeneration risk, but no significant relationship was found.
Zinc also is considered protective against the disorder, though West speculates that her study found no effect because the zinc levels obtain from fish and seafood were low, compared to supplement levels.
Information on the eating of fish and shellfish was examined in the study over a one-year period for 2,391 people 65 to 84 who lived along Maryland’s eastern shore.
After dietary assessments were completed, participants were evaluated for macular degeneration; 1,942 people did not have the disorder and 227 had early macular degeneration. In addition, 153 had intermediate-stage disease and 68 advanced macular degeneration.
The retinas in the advanced group exhibited abnormal blood vessel growth and bleeding, which can lead to blindness or severe vision loss.
People in the group with advanced macular degeneration were significantly less likely to eat omega-3-rich fish and shellfish.
“In conclusion, our results suggest a protective effect of selective fish and shellfish intake against the risk of advanced [age-related macular degeneration], most likely because of their omega-3 fatty acid content,” the researchers write.