Retinitis Pigmentosa, Omega-3s Slow Vision Loss by 40%
Retinitis Pigmentosa: disease progression strongly slowed thanks to fish oil
The combination of a diet rich in Omega-3 fatty acids Omega-3 and the intake of vitamin A supplements can strongly slow the loss of vision in those suffering from retinitis pigmentosa. This discovery was made by researchers from Harvard University (Boston, USA), thanks to data collected during a study published in the Archives of Ophthalmology. The research found that the consumption of at least 0.2 grams per day of Omega-3 reduces by 40% each year the speed of loss of distance visual acuity. According to the US team led by Eliot Berson, this effect could allow patients to maintain vision for 18 years longer.
Retinitis pigmentosa and vision loss
Retinitis pigmentosa is a genetic disease that affects the eyes. One in every 4,000 people suffers from it, totaling 2 million individuals worldwide affected by the disease. This condition causes night blindness already during adolescence. In young adults, the situation worsens, progressing to loss of peripheral vision. Further symptom worsening manifests as a restriction of the eye’s capacity to tunnel vision, allowing to see only what is in the central part of the visual field. Currently, there is no effective cure for this disease and blindness generally develops by the age of 60.
The clinical study
The discovery by Harvard researchers was made possible by 3 clinical trials that involved, in total, 357 patients affected by retinitis pigmentosa. All participants took a daily vitamin A supplement in the form of palmitate. Berson and colleagues demonstrated that individuals who, in addition to vitamin A, also consume at least 0.2 grams per day of Omega-3 experience a 40% slower decline in distance visual acuity compared to those who intake low amounts of these nutrients. The intake of Omega-3 also reduces by about 50% the speed of loss of sensitivity in the central part of the visual field.
The benefits of Omega-3 for vision
Based on these results, researchers concluded that the combination of a diet rich in Omega-3 and vitamin A intake could allow many individuals affected by retinitis pigmentosa to maintain both visual acuity and a good central visual field for most of their life. Indeed, the action of Omega-3 and vitamin A would allow preserving the central functions of the retina. In particular, Berson hypothesizes that the action of vitamin A is enabled by docosahexaenoic acid (DHA), an Omega-3 present in fish oil. In retinitis pigmentosa, the degeneration of rods – essential elements of the eye for vision – would lead to a deficiency of both vitamin A and DHA. The intake of these two nutrients would counteract the vision damage resulting from this situation.
Source
1. Berson EL, Rosner B, Sandberg MA, Weigel-DiFranco C, Willet WC, “Omega-3 Intake and Visual Acuity in Patients With Retinitis Pigmentosa Receiving Vitamin A”, Arch Ophthalmol., Published online ahead of print, doi:10.1001/archopthalmol.2011.2580
