Written by Marcia J. Egles, MD. A clinical trial has reported a benefit of lutein supplementation to the established vitamin A treatment of retinitis pigmentosa.

A recent clinical trial has reported a benefit of lutein supplementation to the established vitamin A treatment of retinitis pigmentosa (1). Retinitis pigmentosa is an eye disease that gradually leads to blindness. An estimated one in 4000 persons in the United States is affected. The visual loss is due to progressive and permanent degeneration of rod and cone photoreceptors in the retina. Many with this affliction are legally blind with loss of peripheral vision by the age of forty. Often the remaining central vision is lost after the age of sixty.

A previous randomized trial of vitamin A and vitamin E supplementation by mouth for adults with retinitis pigmentosa found a slower rate of disease progression in those who received 15,000 IU per day (high dose) of vitamin A palmitate (2). Those given vitamin E at 400 IU per day had a faster worsening (therefore vitamin E supplementation is not currently recommended). The dietary data from that study also suggested a possible benefit of the nutrient lutein.

Lutein is a carotenoid found in leafy, dark-green vegetables such as spinach. Lutein is a component of the pigment of the retina. There is no established dietary recommended intake for lutein, however 6 milligrams per day has been associated with a reduced risk of cataracts and age-related macular degeneration (3,4,5). It is estimated that most Americans only ingest 1 to 2 milligrams of lutein daily in their diet (6).

After several years of preliminary research to establish lutein’s safety in nonsmoking, nonpregnant adults, a dosage of 12 milligrams per day of supplemental lutein was selected as optimal to achieve both serum and retinal elevations of lutein. In July of 2003, the four year double-blinded, randomized, controlled trial of lutein was commenced in patients with retinitis pigmentosa who were already receiving vitamin A. Two hundred and twenty-five men and women with retinitis pigmentosa, aged 18 to 60 and from multiple eye clinics across the United States, were randomly assigned to receive either a 12 milligram per day lutien tablet or a cornstarch tablet control. All the patients continued to receive their usual 15000 IU per day dose of vitamin A. One year into the study, all the patients were also advised to eat 1-2 servings per week of oily fish as a trial of DHA (Docosahexaenoic Acid) supplementation had shown its benefit to retinitis pigmentosa patients (7). Eye exams with visual field testing and assessments of retinal pigment levels were conducted in the four year follow-up. Capsule counts indicated a 92 to 95 per cent compliance rate of the participants consuming their assigned tablets. Ninety per cent reported eating the fish as advised, up from 54 per cent at the start of the study.

A significant ( p equal to 0.05) reduction in the rate of visual loss in the mid-peripheral visual field of the patients receiving lutein was observed. Patients receiving lutein lost an average of 27 points of visual field per year while those without lutein supplement lost 34 points per year. With these losses, the average patient who began at age forty to take lutein could expect to lose the midperipheral field by age 61. In comparision, the same patient without lutein would be expected to have the same loss by age 51.

For central vision, no differences in the rates of visual loss were demonstrated between the two groups.

To avoid the possibility of vitamin A toxicity, retinitis pigmentosa patients require annual serum vitamin A levels and liver function tests. There has been concern that a high dose of vitamin A is not appropriate for smokers or for pregnant women (8). As the long-term safety of higher dose lutein has not been established, no patients should exceed 12 milligrams of lutein per day (1).

Source: Berson, Eliot L., et al. “Clinical trial of lutein in patients with retinitis pigmentosa receiving vitamin A.” Archives of Ophthalmology 128.4 (2010): 403.

© 2010 American Medical Association. All rights reserved.

Posted May 6, 2010.

References:

  1. Berson, EL Clinical Trial of Lutein in Patients WithRetinitis Pigmentosa Receiving Vitamin A Arch Ophthalmol 2010: 128(40: 403-411.
  2. Berson EL. Et al . A randomized trial of Vitamin A and vitamin E supplementation for retinitis pigmentosa. Arch Ophthalmol. 1993;111(6):761-772. Free Radicals and Aging. Basel, Switzerland: Birkhauser; 1992.
  3. Brown L, Rimm EB, Seddon JM, et al. A prospective study of carotenoid intakeand risk of cataract extraction in US men. Am J Clin Nutr. 1999;70(4):517-524.
  4. Chasan-Taber L, Willett WC, Seddon JM, et al. A prospective study on vitaminsupplement intake and cataract extraction among US women. Epidemiology. 1999; 10(6):679-684.
  5. Seddon JM, Ajani UA, Sperduto RD, et al; Eye Disease Case-Control Study Group.Dietary carotenoids, vitamins A, C, and E, and advanced age-related macular degeneration. JAMA. 1994;272(18):1413-1420.
  6. Mohammedshah FY, Douglass JS, Amann MM, Heimbach JM. Dietary intakes of lutein and zeaxanthin and total carotenoids among Americans age 50 and above [abstract]. FASEB J. 1999;13:A554.
  7. Berson EL, Rosner B, Sandberg MA, et al. Further evaluation of docosahexaenoic acid in patients with retinitis pigmentosa receiving vitamin A treatment: subgroup analyses. Arch Ophthalmol. 2004;122(9):1306-1314.
  8. Satia JA, Littman A, Slatore CG, Galanko JA, White E. Long-term use of betacarotene, retinol, lycopene, and lutein supplements and lung cancer risk: results from the VITamins and Lifestyle (VITAL) Study. Am J Epidemiol. 2009;169 (7):815-828.