The study was observational, so it's too early to recommend that people start changing their diet to prevent AMD, the authors note.
But they say their findings support earlier research linking slower progression of AMD to consumption of fish rich in omega-3 fatty acids such as salmon, trout, sardines, herring and tuna.
"Other than giving up cigarette smoking or never starting smoking, there are no known ways to prevent AMD," said coauthor William G. Christen of the Brigham and Women's Hospital in Boston.
For a study published online today in the Archives of Ophthalmology, Christen and colleagues used questionnaire data from the Women's Health Study.
After 10 years, 235 out of 38,022 women aged 45 and older at baseline had developed AMD severe enough to damage their vision.
When the researchers looked at all food sources of the important fatty acids, the risk of AMD was 38% lower in women with highest tertile of intake vs. the lowest. For those who got a lot of EPA, the risk was 34% lower.
"We also looked at the food intake of (just) fish and the data were consistent there," said Christen.
The results support the need for randomised trials, said Christen. In the meantime, he adds, "The best advice we have at this point is, don't smoke."(Reuters Health/ March 2011)
Omega 3 vs. Omega 6