There are two views on the current status of omega-3 oils and their effects on eye health. There is the view of the research and there is the view of the researchers. The research has over and over demonstrated that fish oils (EPA and DHA) have a positive impact on protecting our eyes and helping them continue to function longer throughout our lives. The reason the researchers haven’t made definitive recommendations that people should use fish oils for eye health is that there aren’t enough good randomized, double-blind, crossover, placebo-controlled trials validating these results. I understand the hesitancy of the researchers to take a definitive stance because they are constrained by the standards of the scientific community, but if you were to ask individual researchers if it makes sense to add fish oil to one’s diet to support eye health, they would agree.
Fish oil studies have shown benefits to numerous aspects of eye health. For example, a 2010 study by Matesanz et al showed that EPA and DHA improved nitric oxide production in the eye and reduced the production of the superoxide free radical. Also in 2010, Li et al from the Louisiana State University Health Sciences department examined the effects of fish oil on dry eye in a mouse model by examining one of the downstream metabolites of EPA known as RvE1. Their conclusion was that “RvE1 promotes tear production, corneal epithelial integrity, and a decrease in inflammatory inducible COX-2.” Researchers reproduced similar results in humans in 2011 at the University of Texas Southwestern Medical Center at Dallas in a double-blind, placebo-controlled study on dry eye. In this study, 70% of the subjects in the treatment group were asymptomatic by the end of the study while only 7% were asymptomatic in the placebo group. The omega-3 group was also objectively shown to increase tear volume and tear production. In 2011, a study from the Sainte-Justine University Hospital Research Center in Montreal by Jacques et al even showed that mothers who consumed greater amounts of fish improved the child’s vision development. The researchers stated that “DHA is particularly important for the early development and long-term function of the visual parvocellular pathway.” Again in 2011 in Neurology of Aging, Stough et al in a triple-blind placebo-controlled randomized repeated-measures trial showed that subjects receiving EPA and DHA had significantly better visual acuity by the end of the trial than those receiving a placebo. In a very impressive epidemiological study looking at the food diaries of over 38,000 women published in the Archives of Ophthamology in 2011, researchers examined whether or not the consumption of fish or fish oils would affect the occurrence of age-related macular degeneration (AMD). The data revealed that the women who consumed the greatest amount of fish were the least likely to develop AMD.
These examples have only been a very small sampling of the existing research—there are many more studies. Interestingly, even though the researchers’ conclusions often state the positive effects of fish oil, the researchers still hesitate to state that physicians should begin recommending fish oil to their patients. This does not mean the scientists aren’t doing great work because they are. They are simply less likely to make definitive recommendations to the medical community without huge, double-blind studies. Remember, it was only a few years ago that cardiologists began recommending omega-3s for heart health. The massive medical bureaucracies may be slow to act, but we as consumers can make our own decisions and anyone concerned about their eye health should add fish oil to their supplement program.
Invest Ophthalmol Vis Sci. 2010 Dec;51(12):6815-25. Epub 2010 Aug 11.Docosahexaenoic acid improves the nitroso-redox balance and reduces VEGF-mediated angiogenic signaling in microvascular endothelial cells.Matesanz N, Park G, McAllister H, Leahey W, Devine A, McVeigh GE, Gardiner TA, McDonald DM.
Centre for Vision and Vascular Science, Queen's University Belfast, Northern Ireland, United Kingdom
J Ocul Pharmacol Ther. 2010 Oct;26(5):431-9.Resolvin E1 improves tear production and decreases inflammation in a dry eye mouse model.Li N, He J, Schwartz CE, Gjorstrup P, Bazan HE.
Neuroscience Center of Excellence and the Department of Ophthalmology, Louisiana State University Health Sciences Center , New Orleans, LA 70112, USA.
J Pediatr. 2011 Jan;158(1):83-90, 90.e1. Epub 2010 Aug 25.Long-term effects of prenatal omega-3 fatty acid intake on visual function in school-age children.Jacques C, Levy E, Muckle G, Jacobson SW, Bastien C, Dewailly E, Ayotte P, Jacobson JL, Saint-Amour D.Sainte-Justine University Hospital Research Center, Montreal, Quebec, Canada.
Cornea. 2011 Mar;30(3):308-14.Pilot, prospective, randomized, double-masked, placebo-controlled clinical trial of an omega-3 supplement for dry eye.Wojtowicz JC, Butovich I, Uchiyama E, Aronowicz J, Agee S, McCulley JP.Department of Ophthalmology, The University of Texas Southwestern Medical Center at Dallas, Dallas, TX 75390-9057, USA.
Neurobiol Aging. 2011 Apr 30. [Epub ahead of print]The effects of 90-day supplementation with the Omega-3 essential fatty acid docosahexaenoic acid (DHA) on cognitive function and visual acuity in a healthy aging population.Stough C, Downey L, Silber B, Lloyd J, Kure C, Wesnes K, Camfield D.
National Institute of Complementary Medicine (NICM) Collaborative Centre for Neurocognition, Brain Sciences Institute, Swinburne University of Technology.
Int Ophthalmol. 2011 Feb;31(1):73-82. Epub 2010 Sep 23.Prevention of age-related macular degeneration.Wong IY, Koo SC, Chan CW.Eye Institute, University of Hong Kong, Hong Kong, Hong Kong. ianyhwong@gmail.com
Arch Ophthalmol. 2011 Mar 14. [Epub ahead of print]Dietary {omega}-3 Fatty Acid and Fish Intake and Incident Age-Related Macular Degeneration in Women.Christen WG, Schaumberg DA, Glynn RJ, Buring JE.Schaumberg, Glynn, and Buring) and Aging (Dr Buring), Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, the Department of Biostatistics, Harvard School of Public Health (Dr Glynn), and the Department of Ambulatory Care and Prevention, Harvard Medical School (Dr Buring), Boston, Massachusetts.
Prostaglandins Leukot Essent Fatty Acids. 2009 Aug-Sep;81(2-3):151-8. Epub 2009 Jun 7.Toward optimizing vision and cognition in term infants by dietary docosahexaenoic and arachidonic acid supplementation: a review of randomized controlled trials.Hoffman DR, Boettcher JA, Diersen-Schade DA.Retina Foundation of the Southwest, 9900 N. Central Expwy, Dallas, TX 75231, USA. dhoffman@retinafoundation.org