Nutrient - Lutein may have the potential to add many years of useful vision
According to the findings of a well-designed study published in the April 2010 Archives of Ophthalmology, supplementing with lutein may help to slow the progression of a degenerative eye disease called ‘retinitis pigmentosa’.
Lutein is a naturally occurring carotenoid, which is present in certain plants and also found in the healthy retina. Retinitis pigmentosa (RP) is an inherited eye disease that causes slow progressive degeneration of the retina, the paper-thin tissue that lines the back of the eye like the film in a camera. It usually starts with night blindness or the inability to see clearly in darkness or dim light. Later peripheral vision (which simply means being able to see out of the corner of your eye) declines leading to what is called ‘tunnel vision’. As the disease progresses, central vision (which is necessary for reading) also deteriorates. It is estimated that RP affects approximately 1 in 3,000 to 4,000 people.
Eliot L. Berson, M.D., a Professor of Ophthalmology at Harvard Medical School in Boston, and colleagues had previously shown, in a six-year study involving 600 patients with RP, that vitamin A slowed the progression of RP by about 20% per year.1Subsequently, they showed that a diet rich in omega-3 fatty acids can further slow progression of RP among patients taking vitamin A.2
Recently, the Harvard research group decided to go one step further and determine whether the addition of lutein, among patients already taking vitamin A and consuming a diet rich in omega-3 fatty acids, could further slow the decline in visual function.3In a randomized, double-blind, placebo-controlled study (the ‘gold standard’ in medical research), 225 non-smoking men and women aged 18-60 years with RP were given 15,000 International Units (IU) of vitamin A per day and either 12 milligrams of lutein or a placebo (dummy) tablet to take daily. All of the study participants were told to eat 1 or 2 servings of oily fish weekly to increase their intake of the omega-3 fatty acids EPA and DHA. Researchers followed the study participants for four years, collecting information from annual eye exams and monitoring blood lutein levels.
The researchers showed that over the course of the 4-year study, all participants experienced some vision loss. However, vision loss was significantly slower among those with the highest blood levels of lutein compared with those who had the lowest. The researchers estimated that a daily supplement of lutein in combination with vitamin A and oily fish could preserve side (mid-peripheral) vision for 3 to 10 additional years among those with RP; and concluded: “The randomized comparisons……provide evidence to support the use of 12mg/d lutein supplementations among adults with typical retinitis pigmentosa also taking 15,000 IU/d of vitamin A palmitate and eating one to two servings of oily fish per week.”
1. Berson EL, Rosner B, Sandberg MA, Hayes KC, Nicholson BW, Weigel-DiFranco C, and Willett W. A randomized trial of vitamin A and vitamin E supplementation for retinitis pigmentosa. Arch Ophthalmol 1993;111:761-72.
2. Berson EL, Rosner B, Sandberg MA, Weigel-DiFranco C, Moser A, Brockhurst RJ, Hayes KC, Johnson CA, Anderson EJ, Gaudio AR, Willett WC, and Schaefer EJ. Further evaluation of docosahexaenoic acid in patients with retinitis pigmentosa receiving vitamin A treatment: subgroup analyses. Arch Ophthalmol 2004;122:1306-14.
3. Berson EL, Rosner B, Sandberg MA, Weigel-DiFranco C, Brockhurst RJ, Hayes KC, Johnson EJ, Anderson EJ, Johnson CA, Gaudio AR, Willett WC, and Schaefer EJ. Clinical trial of lutein in patients with retinitis pigmentosa receiving vitamin A. Arch Ophthalmol 2010;128:403-411.