Vitamins E, C May Not Reduce Risk for Vision Loss

Supplementation with vitamins E and C may not reduce the risk for age-related macular degeneration, according to a new study.

Macular degeneration is a degenerative disease of the retina (a thin layer of nerve cells that lines the back of the eyeball) that causes progressive loss of central vision. Like other antioxidants, vitamin E has been suggested to prevent, slow progression or improve macular degeneration. The scientific evidence in this area is not conclusive, although there is some suggestion that vitamin E alone or in combination with beta-carotene, may not be beneficial. There is also a lack of evidence showing the beneficial effects of vitamin C alone for this condition. Further research is warranted.

In a new study, researchers evaluated data on 14,236 healthy male physicians 50 years-old or younger without age-related macular degeneration at the start of the study. Each participant was randomly assigned to receive 400 international units of vitamin E or placebo every other day and 500 milligrams of vitamin C or placebo daily for eight years. Each participant reported any diagnosis of age-related macular degeneration. Questionnaires and medical records were also reviewed.

The researchers found that throughout the eight-year study, a total of 193 cases of age-related macular degeneration were diagnosed. The authors noted that there were close to an equal number of diagnoses of the disorder in both the vitamin E and C groups when compared to the placebo groups.

The authors concluded that longer-term vitamin E and C supplementation may have no effect on the risk for age-related macular degeneration. Further research in this area is warranted.

In addition to vitamins E and C, many other therapies have been reviewed for their potential preventative effects in age-related macular degeneration. Melatonin may exert antioxidant effects, which may contribute to its beneficial effects on the eyes. According to clinical research, melatonin may play a role in protecting the retina to delay macular degeneration. However, data are not conclusive. There is also preliminary research that suggests ginkgo may improve eye blood flow, although it remains unclear if macular degeneration is significantly affected by ginkgo.

For more information about integrative therapies for age-related macular degeneration, please visit Natural Standard's Comparative Effectiveness Database.

For more information about vitamins E or C, please visit Natural Standard's Foods, Herbs & Supplements Database.

Comments

[MS]

I always thought that vitamin A had a relation with maintenance of vision. In another study looking at "The Relationship of Dietary Carotenoid and Vitamin A, E, and C Intake With Age-Related Macular Degeneration in a Case-Control Study" they did not find a relation between these vitamins and decrease in age related macular degeneration. Although they did see improvement in the lutein/zeaxanthin intake group, both are major diet-based macular carotenoids. The study full text link: http://archopht.jamanetwork.com/article.aspx?articleid=419811

[ks]

This is very interesting. I think focus should be on preventing vision loss. Many people suffer from vision problems, but I think the key is prevention and education on what causes vision loss and how to avoid it. I have always heard that eating plenty of carrots (which contain beta carotene) will help strengthen your eyes. However, beta carotene has a Natural Standard scientific evidence grade of D for macular degeneration. I learn something new from NS everyday!

[ns]

I find this very interesting. This is a large sample size and the length of study was very long, which is important in assessing a degenerative disease such as macular degeneration. Although, these supplements might not help with this disease they do have other benefits. It does seem that antioxidants are being shown in a few studies that they are not beneficial in vision loss.

[AB]

Melatonin was brought up as a possible contributor to the protection of retina. Melatonin has a Natural Standard evidence grade of C. In previous studies melatonin has been shown to have the ability to control eye pigmentation and regulate the amount of light reaching the photoreceptors, scavenge hydroxyradicals and protect retinal pigment epithelium cells from oxidative damage.

[Charles]

It's a shame that these two vitamins don't reduce vision loss. However, vitamin A may help those that suffer from Retinitis Pigmentosa or Xerophthalmia (dry eye). A sweet potato a day may keep the optometrist away!

[JW]

This is an interesting study because it shows long-term use of Vitamin E and C. Evidence in long-term studies shows whether products actually have benefit or not. Although these vitamins did not prevent macular degeneration, others have brought up a good point whether it will help slow the progression of the disease. More studies of people with the disease will be needed to be able to determine whether it has other benefits with the disease. I am also surprised that Lutein is evidence level of C, something that I also assumed had more evidence to support its use. This shows that its important to see evidence behind different products to see whether they are beneficial or not.

[KM]

I used Natural Standards Comparative Effectiveness Database and also saw that spinach could potentially be used for macular degeneration. Thats because spinach contains things like lutein and zeaxanthin which are compounds highly concentrated in the eye. Specifically, these compounds are found in and area of the high that has the highest acuity. So maybe looking into other products that have high concentrations of lutein and zeaxanthin would also help to reduce macular degeneration?

[LB]

This is really interesting. The size of the study and the length help to support the results. Maybe the products used in combination with other supplements would be more beneficial. Like jared pointed out i'm curious what effects they might have on the progression of the disease.

[LT]

There was recently a study done on a sample group of male physicians to see the effectiveness of vitamin E and C on the prevention of macular degeneration. This is interesting study because it found that there was no significant benefit or harm from taking vitamin E and C. Some other interesting options for macular degeneration that were remarkable were melatonin, gingko, and shark cartilage.

[BA]

This study brings more controversy to the benefits of antioxidants for vision loss. If you look at the AREDS study design they compared zinc alone, antioxidants alone and a combo of both(formula mentioned above). The combo reduced the risk by 25% vs. zinc alone 21% and antioxidants alone 17%. There might be something about the combination that gives additive effect. I also looked at the monographs in Natural Standard website to see what kind of evidence is available but it is also controversial

[Jared]

I've dispensed the AREDS formula eye multivitamins in my pharmacy many times, so I was wondering how this new study compares to the AREDS study. The AREDS study and formula contains 500 mg vitamin C, 400 IU vitamin E, 15 mg beta-carotene, 80 mg zinc, and 2 mg copper. The AREDS study found a significant reduction in the risk of advanced macular degeneration in people who were at high risk or had already developed macular degeneration. I wonder if vitamins C and E only help once the macular degeneration disease process has begun.