Could There Be Another Reason to Get Hooked on Fish Oil?November 25th, 2013
by Trevor Stump, PharmD student
Fish oil supplements have obtained an impressive track record within scientific literature for improving heart health and lowering triglyceride levels.1 However, the scope of the benefits of these supplements may expand further, as research has recently suggested that the anti-inflammatory effects of omega-3 fatty acids found in fish oil may reduce symptoms of macular degeneration.2 Age-related macular degeneration (AMD) results from damage to the cells of the macula, or central section of the retina, in the eye. This portion of the eye processes close up visual information, so as it deteriorates tasks such as reading or recognizing faces become strenuous. AMD comes in either a dry or wet form, and up to this point, there are no treatment options available for dry AMD. While the cause of the disease is not fully understood, researchers believe that both oxidative stress and inflammation play key roles in its progression.2 As scientists have developed an understanding of the body’s inflammatory response, they have recognized the importance of a certain class of inflammatory mediators known as resolvins, which decrease inflammation by limiting the production of both inflammatory cells and chemicals and inhibiting their transport to sites of inflammation. These mediators are produced through the breakdown of omega-3 fatty acids which are found in large quantities in fish oil supplements.3
A recent article in Natural Standard examines a pilot study conducted to examine the potential for the treatment of dry AMD with high doses of omega-3 fatty acids from fish oil supplements.4 The study, published in PharmaNutrition, gave patients daily high-dose omega-3 fatty acid supplements. The patients were then evaluated for visual acuity using an eye examination every six weeks for six months. The results showed that every patient examined showed at least one line of improvement by the end of the six month period with patients improving by an average of two lines.2 With a 100% improvement rate, this study demonstrates the promise that fish oil supplements provide for the treatment of dry AMD. 
While this article certainly shows fish oil’s potential, the study has its fair share of limitations. The study is classified as a preliminary pilot study, thus it lacked many key aspects needed in a well-designed clinical trial. The researchers involved freely acknowledge these limitations, and explain that better controlled studies will be necessary to make any substantial claims. First, the study sample was too small to provide enough statistical power to get significant results. Furthermore this study did not include a placebo-control group, meaning the researchers had nothing to compare the experimental results to. In addition, the dosage of fish oil administered in this study was relatively high compared to the dosage available over the counter. Because there was such limited control, the conclusions drawn from this study are certainly restricted. As the researchers involved noted, there is a need for further research before any definitive conclusions can be drawn. While several studies evaluate AMD symptom alleviation from dietary fish intake or fish oil in combination with other products, few if any studies examine fish oil supplements alone for the treatment of AMD. On top of this, up to this point the research that is available has produced inconclusive evidence.5,6,7 Because of the conflicting evidence, I am hesitant to support the claims in the article from Natural Standard. It appears that there is some promise for the use of fish oil in treatment for AMD, but the evidence is clearly insufficient at this point, and further research is necessary before healthcare providers can be confident in its effectiveness for this indication.
While the evidence for fish oil supplements in the treatment of AMD is certainly conflicting, fish oil has been found to have limited side effects, and very few if any serious side effects.8 Since there is no indicated treatment for dry AMD and these supplements have been shown to be well tolerated, the potential reward seems to greatly outweigh any risk involved. In light of this, I could understand the reasons a healthcare provider might recommend the supplement for alleviating dry AMD symptoms. Still, without solid evidence to back it up, any recommendation must be accompanied with patient education on the supplement in order to temper a patient’s expectations. Patients must understand that while the supplement will likely not harm them, it may not help them either. With no other treatment options available, the research behind this promising avenue for the treatment of dry AMD becomes even more important. As research continues, hopefully more conclusive evidence will be produced, giving healthcare providers a better understanding of what to expect from this product.
What do you think? Should healthcare providers recommend fish oil for AMD even though the research is inconclusive?
1. Krinsky, D. L., Berardi, R. R., & Ferreri, S. P. (2011). Handbook of nonprescription drugs: An interactive approach to self-care (17th ed.). Washington, D.C: American Pharmacists Association.
2. Georgiou T, Neokleous A, Nicolaou D, Sears B. Pilot study for treating dry age-related macular degeneration (AMD) with high-dose omega-3 fatty acids. PharmaNutrition. 2013. Accessed November 15, 2013.
3. Serhan CN, Hong S, Gronert K, et al. Resolvins: A Family of Bioactive Products of Omega-3 Fatty Acid Transformation Circuits Initiated by Aspirin Treatment that Counter Proinflammation Signals. Journal of Experimental Medicine. 2002;196(8):1025-1037. Accessed November 15, 2013.
4. Natural Standard. Omega 3 fatty acids may reduce symptoms of macular degeneration. Natural Standard. 2013. http://www.naturalstandard.com/news/news201311006.asp. Accessed November 15, 2013.
5. Seddon JM, Cote J, Rosner B. Progression of age-related macular degeneration: association with dietary fat, transunsaturated fat, nuts, and fish intake. Arch Ophthalmol. 2003;121(12):1728-37. Accessed November 15, 2013.
6. Sangiovanni JP, Chew EY, Clemons TE, et al. The relationship of dietary lipid intake and age-related macular degeneration in a case-control study: AREDS Report No. 20. Arch Ophthalmol. 2007;125(5):671-9. Accessed November 15, 2013.
7. Lutein + zeaxanthin and omega-3 fatty acids for age-related macular degeneration: the Age-Related Eye Disease Study 2 (AREDS2) randomized clinical trial. JAMA. 2013;309(19):2005-15.
8. Villani AM, Crotty M, Cleland LG, et al. Fish oil administration in older adults: is there potential for adverse events? A systematic review of the literature. BMC Geriatr. 2013;13(1):41.