News - Oily fish may delay the risk of AMD
It is always refreshing to get a different take on the omega 3 story and it now seems, according to a newly published study, that a diet rich in long-chain omega 3 fatty acids may lower the risk of vision loss associated with advanced age-related macular degeneration.
Age-related macular degeneration (AMD) is a debilitating, multi-factorial disease, and the most common cause of blindness in the UK. An estimated 500,000 people in the UK suffer from AMD, and one in fifty people over the age of 65 are blind in one or both eyes due to this condition. This late-onset degenerative disease destroys the central vision required for reading, writing, and driving, leaving just the peripheral vision.
A study, by Bonnielin K. Swenor and colleagues, at Johns Hopkins School of Medicine, analysed data from 2,520 Maryland residents, aged 65 to 84 years.
The volunteers completed dietary food frequency questionnaires and, based on their weekly fish and shellfish consumption, were divided into three groups: less than one serving, one to less than two servings, and two or more servings.
Following completion of dietary assessment, volunteers underwent eye examinations to determine AMD status. In all, 1,942 of the volunteers did not have AMD, 227 had early macular degeneration, 153 had intermediate-stage disease, and 68 had advanced disease.
The results published in the December 2010 issue of Ophthalmology demonstrated that all the volunteers averaged at least one serving of fish or shellfish each week. However, further analysis indicated that those who consumed at least one portion of oily fish each week reduced their risk of advanced AMD by 60% compared to those who ate less than a serving each week.
These findings suggest that a more frequent intake of fish/shellfish high in omega 3 fatty acids may reduce the risk of advanced AMD. This connection is plausible, since studies have shown high levels of omega 3s in the retina. However, because this study was “observational,” it has a number of limitations. Future randomised controlled trials would be preferable in determining if omega 3s really do reduce the risk of AMD. Despite this the study is encouraging, and provides incentive to include omega 3 fatty acids in one’s diet, at least for the purposes of maintaining a healthy lifestyle. Watch this space for future developments.
Swenor BK, Bressler S, Caulfield L, and West SK. The impact of fish and shellfish consumption on age-related macular degeneration. Ophthalmology 2010; 117:2395-401.