Omega-3 Helps Prevent Macular Degeneration
The addition of omega-3 fatty acid to the diet can help prevent the development of age-related macular degeneration vision loss by more than 30 percent, according to a new study from the National Eye Institute. Macular degeneration is the leading cause of blindness in people older than 50.
Age-related macular degeneration is a degenerative eye disease that affects central vision and leaves only peripheral sight. An estimated 2 million Americans and 25 to 30 million people worldwide have macular degeneration, and as the Baby Boomer generation ages, the incidence is expected to rise significantly.
Of the two types of macular degeneration - wet and dry - the dry form accounts for 85 to 90 percent of cases. Dry macular degeneration occurs when normal tissues in the macula, the portion of the retina responsible for central vision, slowly deteriorates. The wet form develops when blood vessels under the macula grow abnormally, eventually leak, and scar the macula. Wet macular degeneration is the form that typically results in more severe vision loss.
The current study, which was published online in the American Journal of Clinical Nutrition, supports the results of an earlier (2008) study which reported that high intake of omega-3 fatty acids and fish may reduce the risk of macular degeneration by up to 38 percent. According to that research, the advantages of consuming omega-3 were most prominent in people who had advanced disease, while eating fish twice weekly was associated with a reduced risk of both early and late stage macular degeneration.
In the new study, the researchers evaluated a subgroup of the Age-Related Eye Disease Study (AREDS), a major study conducted by the National Eye Institute that produced strong evidence that certain nutrients could help prevent or slow progression of dry macular degeneration. The first results were released in 2001, and a second study, AREDS2, is currently underway. The scientists in the new study looked at 1,837 people who participated in phase 3 of the AREDS and who had a moderate to high risk of advanced macular degeneration.
The scientists found that over 12 years, the participants who had the highest omega-3 intakes had a 30 percent lower risk of developing both types of macular degeneration compared with people who had the lowest intakes. Since omega-3 fatty acids cannot be manufactured by the body, it is essential that people get them through their diet. Sources of omega-3 fatty acids include fish such as salmon, herring, tuna, halibut, and sardines, and nut oils (e.g., walnuts, Brazil nuts, macadamia nuts).
Consumption of omega-3 fatty acids has also been found to provide other health benefits, including:
* Reducing the risk of heart disease
* Lowering blood pressure
* Aiding in weight loss
* Helps improve bone strength
* Fights depression
* Reduces arthritis symptoms
* Helps people with diabetes
* May benefit people with attention deficit hyperactivity disorder (ADHD)
The findings in this study support earlier research and thus significantly strengthen the argument that omega-3 fatty acids are an essential part of the diet. Along with helping to prevent or slow macular degeneration, inclusion of foods rich in omega-3 fatty acids and/or taking omega-3 supplements appears to be a wise choice for health-conscious consumers, especially those concerned about macular degeneration.
Chong EW et al. Archives of Ophthalmology 2008 Jun; 126(6): 826-33
National Eye Institute
SanGiovanni JP et al. American Journal of Clinical Nutrition 2009 October doi: 10.3945/ajcn.2009.27594