Seafood diet may keep vision loss at bay

Eating more seafood rich in omega-3 fatty acids - such as oysters, crabs and tuna - appears to slow advanced macular degeneration, a common cause of age-related blindness, according to new research published in Ophthalmology.

The findings are consistent with previous research suggesting omega-3 supplements and omega-rich diets protect vision in some people, says study author Bonnielin Swenor of the Wilmer Eye Institute at Johns Hopkins School of Medicine.

"Our study shows a dietary effect, that people who had the highest weekly intake of fish and shellfish high in omega-3 fatty acids were significantly less likely to have advanced disease," Swenor says.

The observational study included 2,390 participants ages 65 to 84 on Maryland's Eastern Shore. They were asked to complete a questionnaire about diet habits in the previous year, including how much fish and shellfish they ate. Then they were evaluated for macular degeneration.

Although all of the participants averaged at least one serving of fish or shellfish a week, 68 people who had advanced macular degeneration, including blood vessel problems and atrophy in the retina, were significantly less likely to consume high omega-3 fish and seafoods. That suggests a fish-rich diet helps vision, Swenor says. Another 153 had intermediate-stage disease and 227 had early stages, while 1,942 had no macular degeneration.

"It's an important piece of evidence in the omega-3 story," says Steven Schwartz, Ahmanson professor of ophthalmology at the University of California, Los Angeles' Jules Stein Eye Institute. "It's biologically plausible that the protective effect is from the omega-3s, but it's important to keep in mind that there are potentially other factors at play - genetics, environment and unknowns."

"The fact that it's consistent with other published reports makes it more credible," Massachusetts Eye and Ear Infirmary retina specialist Ivana Kim says. She cautions that the small percentage of people in the study with advanced disease (3 percent) may lead to false conclusions.

Nixing tobacco, controlling blood pressure, eating leafy green veggies and nuts, and seeing a retina specialist if you've already been diagnosed with macular degeneration are other lifestyle recommendations Schwartz says he offers patients. He cautions against self-dosing with omega-3 supplements, though.

"We don't recommend patients go out on their own and supplement like crazy. Talk with your ophthalmologist and get a personalized plan," Schwartz says.

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