HEALTH NEWS

Study Title:

Omega 3 and Macular Degeneration

Study Abstract

Age-related macular degeneration (AMD) is one of the leading cause of blindness among the elderly; however, current therapy options are limited. Epidemiological studies have shown that a diet that is high in -3 polyunsaturated (n-3) fatty acids can slow disease progression in patients with advanced AMD. In this study, we evaluated the effect of such a diet on the retinas of Ccl2–/–/Cx3cr1–/– mice, a model that develops AMD-like retinal lesions that include focal deep retinal lesions, abnormal retinal pigment epithelium, photoreceptor degeneration, and A2E accumulation. Ccl2–/–/Cx3cr1–/– mice that ingested a high n-3 fatty acid diet showed a slower progression of retinal lesions compared with the low n-3 fatty acids group. Some mice that were given high levels of n-3 fatty acids had lesion reversion. We found a shunted arachidonic acid metabolism that resulted in decreased pro-inflammatory derivatives (prostaglandin E2 and leukotriene B4) and an increased anti-inflammatory derivative (prostaglandin D2). We also measured lower ocular TNF- and IL-6 transcript levels in the mice fed a diet of high n-3 fatty acids. Our findings in these mice are in line with human studies of AMD risk reduction by long-chain n-3 fatty acids. This murine model provides a useful tool to evaluate therapies that might delay the development of AMD.

From press release:

Current research suggests that a diet high in omega-3 fatty acids may help prevent one of the leading causes of legal blindness among the elderly. The related report by Tuo et al, "A high omega-3 fatty acid diet reduces retinal lesions in a murine model of macular degeneration," appears in the August 2009 issue of the American Journal of Pathology.

Age-related macular degeneration (AMD), loss of vision in the center of the visual field (macula) due to retinal damage, is one of the leading causes of legal blindness among the elderly. Approximately 10% of people from 66 to 74 years of age will develop some level of macular degeneration, making it difficult for them to read or even recognize faces.

A diet high in omega-3 fatty acids has been found to protect against a variety of diseases including atherosclerosis and Alzheimer's disease. Retrospective studies have suggested that diets high in fish oil or omega-3 fatty acids may also contribute to protection against AMD. A group led by Dr. Chi-Chao Chan at the National Eye Institute in Bethesda, MD examined the direct effect of omega-3 fatty acids on a mouse model of AMD. A diet with high levels of omega-3 fatty acids resulted in slower lesion progression, with improvement in some lesions. These mice had lower levels of inflammatory molecules and higher levels of anti-inflammatory molecules, which may explain this protective effect.

Tuo et al suggest that "a diet enriched in EPA and DHA can ameliorate the progression of retinal lesions in their mouse model of AMD" and that "the results in these mice are in line with the epidemiological studies of AMD risk reduction by long chain n-3 fatty acids." The results "further provide the scientific basis for the application of omega-3 fatty acids and their biologically active derivatives in the prevention and treatment of AMD." In future studies, Dr. Chan and colleagues plan to use this murine model "to evaluate [other] therapies that might delay the development of AMD." Their ongoing projects include the "testing of systematic delivered pharmacochaperones and antioxidative molecules, as well as intraocularly delivered gene therapies."

Study Information

Jingsheng Tuo, Robert J. Ross, Alexandra A. Herzlich, Defen Shen, Xiaoyan Ding, Min Zhou, Steven L. Coon, Nahed Hussein, Norman Salem, Jr and Chi-Chao Chan.
A High Omega-3 Fatty Acid Diet Reduces Retinal Lesions in a Murine Model of Macular Degeneration.
American Journal Of Pathology
2009 July
National Institutes of Health, Bethesda, Maryland.