[excerpted from the book: Natural Eye Care Series: Macular Degeneration for more information click here]
Omega-3 fatty acids. 2,000mg–3,000mg per day. Omega-3 fatty acids are a specific type of essential fatty acid known to reduce inflammation and lower the risk of chronic diseases. Omega-3 fatty acids, found in fish, are a primary component of retinal photoreceptors and of the myelin sheath that surrounds nerve fibers in the eye.
They are so essential to the retina that when omega-3 levels begin to fall, the retina begins to recycle DHA within the eye. The typical American diet is deficient in omega-3 fatty acids but has too much omega-6s (from vegetable oils and refined grains).
There are three types of omega-3 fatty acids: alpha-linolenic acid (ALA), which is found in plant oils; eicosapentaenoic acid (EPA) used primarily in the brain and retina, and docosahexaenoic acid (DHA) used primarily in the heart and circulatory system; the latter two are found in fish oils. EPA and DHA are not naturally present in the body; we can synthesize them from ALA, but this ability declines with age. Therefore, it is important to get adequate EPA and DHA from other sources.
The primary omega-3 fatty acids, DHA and EPA, may protect the retina through expression of genes, retinal cell differentiation, and survival. There has been extensive research about these two omega-3’s and much less about alpha-linolenic acid (ALA). It is likely that the three have very specific and independent roles in protecting against disease.
AMD. DHA has been found to have antioxidative, anti-inflammatory, antiapoptotic, and anti-angiogenic (limiting growth of new blood vessels) effects. While it is known that a low-fat diet (10% from fat) lessens AMD risk, it has been found that omega-3 fatty acids and olive oil further reduce AMD risk.Eighty-five percent of AMD patients over age 70 experienced improved vision after four weeks of supplemental omega-3s. Other reports, such as a meta-analysis of more than 270 studies and papers, a longitudinal study of over 1,800 people over 12 years, and a large 10-year study evaluating the diets of nearly 40,000 women confirmed these findings.A derivative of DHA protects retinal pigment epithelial cells from oxidative stress. Unlike the effect of DHA in other parts of the body such as the liver, it does not appear to be subject to lipid oxidation in the retina.
- DHA reduces inflammation in retinal microcapillaries and in the retina, changing potent inflammatory agents to less powerful ones.[xx] Omega-3s reduce neuroinflammation.
- EPA and DHA have the capacity to regulate formation of blood vessels, which is important with respect to the advanced form of AMD, choroidal neovascularization. They are able to encourage immune cell movement toward the site of extraneous formations of blood vessels that distort vision. The results indicate promising potential for omega-3 as a nutritional therapy that includes other conditions involving both inflammation and neovascularization
- Omega-3 fatty acids are essential for nerve conduction in the retina and for retinal blood flow. Omega-3 DHA is present in large amounts in retinal epithelial cells, acting towards neuroprotection; this understanding presents possibilities for future therapies.
- Cold-water fish, especially mackerel, lake trout, sardines, tuna, and salmon. Also, halibut, river trout, catfish, cod, red snapper, and tuna packed in water.
- Some microalgae, anchovies, salmon, herring, mackerel, tuna, and halibut. Also, liver, fish oil, and eggs from grass fed poultry.