Fatty acids and macular degeneration

High dietary levels of omega-3 long-chain polyunsaturated fatty acids and fish might reduce the risk of age-related macular degeneration (AMD). Macular degeneration is a medical condition predominantly found in elderly adults in which the centre of the inner lining of the eye (retina), known as the macula, undergoes thinning and atrophy. This results in loss of central vision, which leads to an inability to see fine details, to read, or to recognise faces. Neovascular or exudative AMD, the wet form of advanced AMD, causes vision loss due to abnormal blood vessel growth, ultimately leading to blood and protein leakage below the macula. Bleeding, leaking, and scarring from these blood vessels eventually cause irreversible damage to the photoreceptors and rapid vision loss if left untreated. The findings are largely supportive of previous work linking omega-3 long-chain polyunsaturated fatty acids and foods rich in these fatty acids can block or slow age-related macular degeneration. The current study involved an analysis of data for 4,519 American subjects who participated in the Age-Related Eye Disease Study (AREDS). A self-administered food frequency questionnaire was used to assess the subjects' diet content in the year prior to study enrollment. After accounting for overall calories and other variables, those with the highest levels of total omega-3 long-chain polyunsaturated fatty acids in their diet had a 39-percent reduced risk of neovascular age-related macular degeneration compared with those with the lowest dietary levels. The corresponding risk reduction for dietary levels of docosahexaenoic acid, a retinal omega-3 long-chain polyunsaturated fatty acid, was 46 percent. High levels of fish, in general, and broiled or baked fish cut the risk of neovascular age-related macular degeneration by 39 percent and 35 percent, respectively. By contrast, the intake of arachidonic acid, an omega-6 fatty polyunsaturated acid found in phospholipids, cell membrane and brain seemed to increase the risk of neovascular age-related macular degeneration. When compared to subjects with the lowest dietary levels, those with the highest levels had a 54-percent increased risk. The findings suggest that modifying the diet to include more foods rich in omega-3 long-chain polyunsaturated fatty acids and fish reduces the risk of vision loss due to neovascular age-related macular degeneration.