Until now, research from the National Eye Institute and others has shown benefit to taking macular degeneration supplements only after you've developed dry macular degeneration, but before you develop wet macular degeneration.
But a study in the June 2008 issue of the professional journal, Archives of Ophthalmology has finally shown the benefit to previously healthy people in the prevention of both mild and severe forms of macular degeneration.
Researchers from Australia and Singapore published a study entitled, “Dietary Omega-3 Fatty Acid and Fish Intake in the Primary Prevention of Age-Related Macular Degeneration: A Systematic Review and Meta-analysis.”
This meta-analysis consisted of a mathematical evaluation of the results from nine previous studies of nearly 89,000 people, of which more than 3000 developed macular degeneration. The authors found that high dietary intake of Omega-3 fatty acids was associates with a 38% reduction in the risk of late macular degeneration (exudative AMD, wet macular degeneration or geographic atrophy). Furthermore, people who ate fish twice weekly not only reduced their risk of late AMD, but also early AMD (soft drusen or retinal pigmentary changes).
How do Omega-3 Fatty Acids Help Prevent Macular Degeneration?
Omega-3 Fatty acids are called “essential” fatty acids, because humans don't have the ability to synthesize them in their bodies. Therefore, they must get these essential fatty acids from diet or nutritional supplements. Omega-3 fatty acids include alpha-linolenic acid (ALA), docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA). Both DHA and EPA are long-chain omega-3 fatty acids, that protect against oxidative, inflammatory and age-related degenerative changes. These three damaging processes result in the development of age-related macular degeneration. Furthermore, long-chain omega-3 fatty acids, and especially DHA, form a critical part of the healthy retina.
Who Should Take Omega-3 Fatty Acids based on the current study?
The current study found benefit in the prevention of macular degeneration in people that were 49 years or older. This is a very important fact. Because macular degeneration most commonly develops after age 60, this study informs us that ingesting omega-3 fatty acids at least 10 years before that has an important benefit in the prevention of a potentially blinding eye disease.
How does this study compare with AREDS (Age-Related Eye Disease Study)?
The Age-Related Eye Disease Study was completed by the National Eye Institute, part of the United States National Institutes of Health in 2001.
There are two important ways in which this study differs from AREDS.
1. AREDS looked at the benefit to taking nutritional supplements on the progression of macular degeneration in people that already had the disease. In contrast, the omega-3 study evaluated people before they had the disease in an effort to determine whether macular degeneration could be prevented.
2. AREDS was a randomized, prospective double-blind study (neither the participant nor scientists knew whether the the person was receiving real supplement or placebo). The current study of omega-3 essential fatty acids was a meta-analytic mathematical evaluation of prior research that had already been completed. A prospective study is widely considered by the scientific community to be the standard of excellence in research. Nevertheless, the study of omega-3 fatty acids was based upon nine studies that by themselves, were considered to be of excellent design.
Because of the apparent benefits of Omega-3 fatty acids in this and previous studies, the National Eye Institute is currently performing the Age Related Eye Disease Study 2, which is looking at the benefit of omega-3 essential fatty acids, but also of the carotenoids, Lutein and Zeaxanthin.
Reference: Dietary ω-3 Fatty Acid and Fish Intake in the Primary Prevention of Age-Related Macular Degeneration: A Systematic Review and Meta-analysis. Chong E, Kreis A, Wong T, Simpson J, Guymer R. Archives of Ophthalmology, 126(6):826-833. June 2008.