by Craig Weatherby
New findings from the US National Eye Institute suggest that diets rich in omega-3s may slash the risk of the leading cause of age-related blindness by about one-third.
Age-related macular degeneration or AMD eventually leaves a blurry spot in the center of your field of vision. In America and the Western world, AMD is the leading cause of legal blindness among people over 55 years of age.
The macula is a yellow spot near the center of the retina. It’s needed for detailed vision, and also absorbs excess light to protect against UV damage.
There are two types of AMD—wet and dry.
- Wet AMD occurs when blood vessels grow excessively beneath the macula… the blood vessels eventually leaks and the macular is scarred, obscuring vision.
- Dry AMD occurs when normal tissue in the macula slowly disappears. This results in a pale area of the macular.
Prior evidence of benefit
Several sizeable studies already show that omega-3 may protect against the onset of AMD (See “Omega-3s Linked to Eye Health … Again”).
How might omega-3s help?
Omega-3 fatty acids, and particularly DHA, play a crucial role in the health and functioning of nerve cells in the retina.
And a mouse study funded in part by the National Eye Institute found lower levels of pro-inflammatory immune system molecules and higher levels of anti-inflammatory molecules in the eyes of mice fed omega-3s (See “Omega-3s' Eye-Guarding Effects Affirmed”).
Latest study supports USDA dietary recommendations
New research indicates that eating more omega-3 fatty acids from foods or pills may reduce the risk of wet and dry AMD, by 35 and 32 percent respectively. (SanGiovanni JP et al. 2009)
The study authors examined a sub-section of people participating in the Age-Related Eye Disease Study (AREDS), all of whom were considered at a moderate-to-high risk of advanced AMD. They estimated the subjects' omega-3 intakes using a diet questionnaire.
After following them for 12 years, the researchers found that the participants with the highest estimated omega-3 intakes had a 30 percent lower risk of developing either type of AMD, compared to the people with the lowest omega-3 intakes.
These findings bolster conclusions and recommendations published last summer by researchers from the USDA's Human Nutrition Research Center on Aging (Chiu CJ et al. 2009):
- “Recent information suggests that… enhanced intake of omega-3 fatty acids [is]… protective against advanced age-related macular degeneration (AMD)...”
- “A dietary strategy for achieving an optimal [omega-3 intake] level is to consume 2-3 servings per week of cold water fatty fish, such as salmon, tuna, mackerel, sardines, shellfish, and herring.”
- “In order to benefit from higher DHA intakes against early AMD, people should adapt the recommended dietary guideline no later than the age of 60, before the early stages of AMD develop.”
- Chiu CJ, Klein R, Milton RC, Gensler G, Taylor A. Does eating particular diets alter the risk of age-related macular degeneration in users of the Age-Related Eye Disease Study supplements? Br J Ophthalmol. 2009 Sep;93(9):1241-6. Epub 2009 Jun 9.
- SanGiovanni JP, Agrón E, Clemons TE, Chew EY. Omega-3 long-chain polyunsaturated fatty acid intake inversely associated with 12-year progression to advanced age-related macular degeneration. Arch Ophthalmol. 2009 Jan;127(1):110-2.
- SanGiovanni JP, Chew EY, Agrón E, Clemons TE, Ferris FL 3rd, Gensler G, Lindblad AS, Milton RC, Seddon JM, Klein R, Sperduto RD; Age-Related Eye Disease Study Research Group. The relationship of dietary omega-3 long-chain polyunsaturated fatty acid intake with incident age-related macular degeneration: AREDS report no. 23. Arch Ophthalmol. 2008 Sep;126(9):1274-9.
- SanGiovanni JP, Chew EY, Clemons TE, Davis MD, Ferris FL 3rd, Gensler GR, Kurinij N, Lindblad AS, Milton RC, Seddon JM, Sperduto RD; Age-Related Eye Disease Study Research Group. The relationship of dietary lipid intake and age-related macular degeneration in a case-control study: AREDS Report No. 20. Arch Ophthalmol. 2007 May;125(5):671-9.