Harvard researchers report a study in mice found greater intake of long-chain omega-3 essential fatty acids (EFAs) protected against blindness attributed to abnormal ocular blood vessel growth.
Their compatriots at Children’s Hospital Boston, the pediatric teaching affiliate of Harvard Medical School, hope to replicate the findings in premature infants at risk for vision loss due to a lack of omega-3s. Results of the murine study were published in a letter to Nature Medicine.
Researchers fed mice diets that either emphasized docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA) - the pre-formed long-chain omega-3s found in fish oil - or omega-6 fatty acids.
Mice on the omega-3 diet had an area with vessel loss 40- to 50-percent smaller than that of mice on the omega-6 diet, significantly decreasing pathological vessel growth and aiding normal vessel re-growth. Researchers further reported a 2-percent change in omega-3 intake was sufficient to decrease disease severity by 50 percent. Also, the omega-3 based diet suppressed production of tumor necrosis factor-alpha (TNF-alpha), reducing the inflammatory response in the retina, and bolstered production of the anti-inflammatory compounds neuroprotectinD1, resolvinD1 and resolvinE1.
Paul A. Sieving, M.D., Ph.D., director of the National Eye Institute (NEI), which provided funding for the study, said: “This study shows the benefit of dietary omega-3 fatty acids in protecting against the development and progression of retinal disease. It gives us a better understanding of the biological processes that lead to retinopathy and how to intervene to prevent or slow disease. It will be interesting to see if human clinical trials show similar beneficial effects.”
The clinical trial at Children’s Hospital Boston will follow premature newborns who are unable to feed and receiving parenteral nutrition, with omega-3 fatty acids as part of their IV solution. The hope is that the omega-3 supplementation will allow the retina and its vessels to develop normally.
In lieu of eating fish, Omega-3 supplements from Neptune Krill Oil provide a healthy, contaminant-free source of DHA and EPA.
Many sight-threatening diseases have two critical phases, vessel loss followed by hypoxia-driven destructive neovascularization. These diseases include retinopathy of prematurity and diabetic retinopathy, leading causes of blindness in childhood and middle age affecting over 4 million people in the United States. We studied the influence of -3- and -6-polyunsaturated fatty acids (PUFAs) on vascular loss, vascular regrowth after injury, and hypoxia-induced pathological neovascularization in a mouse model of oxygen-induced retinopathy1. We show that increasing -3-PUFA tissue levels by dietary or genetic means decreased the avascular area of the retina by increasing vessel regrowth after injury, thereby reducing the hypoxic stimulus for neovascularization. The bioactive -3-PUFA-derived mediators neuroprotectinD1, resolvinD1 and resolvinE1 also potently protected against neovascularization. The protective effect of -3-PUFAs and their bioactive metabolites was mediated, in part, through suppression of tumor necrosis factor-. This inflammatory cytokine was found in a subset of microglia that was closely associated with retinal vessels. These findings indicate that increasing the sources of -3-PUFA or their bioactive products reduces pathological angiogenesis. Western diets are often deficient in -3-PUFA, and premature infants lack the important transfer from the mother to the infant of -3-PUFA that normally occurs in the third trimester of pregnancy2. Supplementing -3-PUFA intake may be of benefit in preventing retinopathy.
Kip M Connor, John Paul SanGiovanni, Chatarina Lofqvist, Christopher M Aderman, Jing Chen, Akiko Higuchi, Song Hong, Elke A Pravda, Sharon Majchrzak, Deborah Carper, Ann Hellstrom, Jing X Kang, Emily Y Chew, Norman Salem, Jr, Charles N Serhan & Lois E H Smith; Increased dietary intake of -3-polyunsaturated fatty acids reduces pathological retinal angiogenesis - pp 868 - 873; Nature Medicine 2007 (ePub June 24; DOI:10.1038/nm1591).