Retinitis Pigmentosa Slows with Omega-3 Plus Vitamin A

Vision of person with retinitis pigmentosa
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A significant slowing of vision loss is possible among people who have retinitis pigmentosa if they eat a diet rich in omega-3 fatty acids along with taking vitamin A, according to a study published Online First by Archives of Ophthalmology. The combination of omega-3 and vitamin A had a positive impact on both distance and retinal visual acuities.

Omega-3 plus vitamin A offers hope for retinitis pigmentosa

Retinitis pigmentosa is a term that refers to a group of inherited diseases that cause a degeneration of the retina. Individuals who have retinitis pigmentosa experience a gradual loss of vision because their photoreceptor cells (cones and rods) die.

Currently there is no cure for retinitis pigmentosa, although research continues in a variety of areas, including gene therapy. More immediate, however, are other treatments, including vitamin A, which has been a standard treatment since the early 1990s. Vitamin A palmitate helps slow the progression of the disease.

Now it appears that adding omega-3 to a management course that already includes four to six years of taking vitamin A can result in significant reduction in the decline of distance and retinal visual acuities in adults.

To arrive at this conclusion, the authors evaluated the visual acuity data from three trials that involved a total of 357 patients with typical retinitis pigmentosa. All the individuals were taking 15,000 IU of vitamin A palmitate daily.

All the participants completed the Willett food frequency questionnaire at screening and at their annual follow-up visits, during which they underwent a comprehensive eye examination. Based on the information from the questionnaire, the patients were grouped according to omega-3 intake as high (at least 0.2 grams per day, 215 patients) or low (less than 0.2 grams per day, 142 patients).

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Their findings?

  • Individuals with a diet high in omega-3 fatty acids had a 40% slower average annual rate of decline in distance visual acuity than individuals whose diet was low in omega-3s
  • Individuals with a high intake of omega-3s had nearly a 50% slower rate of decline in central visual field sensitivity than those consuming a low amount of omega-3s

Foods that provide the greatest levels of omega-3 fatty acids are cold water fatty fish, such as tuna, salmon, herring, sardines, and mackerel. In this study, the definition of high intake of omega-3 was one to two 3-ounce servings of fatty fish per week, and low was considered to be less than one 3-ounce serving per week.

For individuals who do not like fish, omega-3 supplements are available. Non-fish food sources of omega-3 fatty acids include walnuts and walnut oil, flaxseeds, pumpkin seeds and oil, algae, and soybeans.

The challenge with non-fish sources, however, is that the body must convert the form of omega-3 found in these sources (ALA, or alpha-linolenic acid) to the forms found in fatty fish—eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), both of which the body can utilize much more effectively than ALA.

Anyone with retinitis pigmentosa should discuss their omega-3 needs and how to get a sufficient amount with their physician.

The take-home message from the study is this: The combination of vitamin A and a diet rich in omega-3 fatty acids “should make it possible for many patients with typical retinitis pigmentosa to retain both visual acuity and central visual field for most of their lives,” according to the researchers.

SOURCES:
Berson EL, Rosner B, Sandberg MA, Weigel-DiFranco C, Willett WC. Omega-3 intake and visual acuity in patients with retinitis pigmentosa receiving vitamin A. Archives of Ophthalmology 2012 Feb 13 published online. DOI:10.1001/archophthalmol.2011.2580
Gamel JW, Barr CC. A randomized trial of vitamin A and vitamin E supplementation for retinitis pigmentosa. Archives of Ophthalmology 1993 Nov; 111(11): 1462-63

Image: Courtesy of Wikimedia Commons

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