Visit any pharmacy or health shop and you run the risk of being submerged in supplements, diet pills, fish oil and vitamins. There are options for nearly every condition, every diet, and for every nonsense theory on the internet.
However, as we do not have time for snake oil or holistic gibberish, we only go for medically proven science with a record of application in ophthalmology. That is why we investigated the use of health supplements in both dry and wet age-related macular degeneration (AMD). They are routinely used to help improve the symptoms of AMD, but are they as effective as they’re made out to be?
Age-Related Macular Degeneration (AMD)
AMD is one of the leading causes of visual impairment. It is an insidious condition which builds over time with little to no symptoms during the initial stages. It causes blurred vision in the center of the visual field — and while it doesn’t directly cause blindness, AMD makes it difficult to recognize faces and to carry out day-to-day tasks, like driving and reading.
There are two types of AMD; dry and wet. Dry AMD causes the macula cells to slowly stop working, whereas with wet AMD, the cells stop working and the eye grows new blood vessels to compensate. Neither has a cure, however treatments are available to slow the progression of wet AMD. This has fueled research into the condition, as well as the supplements and medicines that could be used to combat AMD.
The Age-Related Eye Disease Study (AREDS)
The first comprehensive study into AMD and supplements is the Age-Related Eye Disease Study (AREDS) by the National Eye Institute in the U.S. The study examined AMD risk factors and whether supplements like beta-carotene, vitamin C, vitamin E and zinc, among others, could slow AMD progression.
AREDS found that taking supplements could significantly slow the progress of AMD.1 The findings of a follow-up study, AREDS 2, were released in May 2013 and showed the results of tweaking the list of supplements used to combat AMD.
The AREDS 2 study added omega-3 fatty acids as well as the antioxidants lutein and zeaxanthin, all of which are in the same category of nutrients as beta-carotenes. This was particularly important as beta-carotene can lead to an increased risk of lung cancer in smokers, a common underlying cause of AMD. The study showed that omega-3 fatty acids had little effect, but that lutein and zeaxanthin were safe alternatives to beta-carotene.2
Supplements and their Success
Lutein and zeaxanthin have become standard medicine for AMD. Both perform antioxidant functions for the body and protect against free radical molecules.
Lutein in particular has proven popular in treating AMD. A common xanthophyll, it is frequently encountered in fruit, cereals and vegetables — and in particular egg yolks. According to one study published in 2018, Lutein has a remarkable effect on slowing the progression of AMD:3
The authors carried out a number of experiments on patients with AMD at various stages. In one intervention trial 37 patients with dry AMD in one or two eyes were provided with an 8mg Lutein dose. Significant improvement in visual acuity was observed over six months, a result corroborated by other trials carried out by the study.
A number of studies also point to the efficacy of these supplements in improving general eyesight quality. According to a study published in the Journal of Optometry, patients with AMD who consumed 8mg of zeaxanthin per day over the course of one year saw an average improvement of 1.5 lines on their visual acuity.4
New Ideas Emerge
Scientific consensus remains in favor of using supplements to treat AMD. A number of recent studies have continued to emphasize the importance of using supplements. Geographic location does however cause variance in treatment.
One study, “Do Nutritional Supplements Have a Role in Age Macular Degeneration Prevention?” noted that doses of vitamins and minerals to treat AMD are lower in Europe than in the United States. The study concluded that patient outcomes could therefore vary and called for a European focused study.5
In April 2019, another study examined what nutrients can be used to prevent macular degeneration and eye-related diseases. Similar to the aforementioned study, it found that nutrients like vitamin E and zinc are beneficial in patient treatment.
However, it also found that in most of the studies it covered, vitamin and mineral supplements failed to significantly improve eye condition or AMD in patients. In its conclusions, this study also called for more research focused on the use of specific formulas with a combination of antioxidants to prevent early AMD development.6
This study points to an emerging trend in research and academic papers, where the value of applying nutritional supplements to prevent and alleviate both types of AMD is beginning to be challenged.
More research is required before the standard application of supplements to treat AMD changes, but we are likely to see more research challenging the use of said supplements. For now, the vast bulk of scientific research and evidence suggests that supplements like lutein and zeaxanthin should continue to be applied against AMD.
References
1. Bressler NM, Bressler SB, Congdon NG, et al. The Age-Related Eye Disease Study (AREDS). Control Clin Trials. 1999;20(6):573–600.
2. Chew EY, Clemons T, SanGiovanni JP, et al. The Age-Related Eye Disease Study 2 (AREDS2). Ophthalmology. 2012;119(11):2282–2289.
3. Buscemi S, Corleo D, Di Pace F, et al. . The Effect of Lutein on Eye and Extra-Eye Health. Nutrients. 2018;10(9):1321.
4. Mousavi M, Armstrong RA. Genetic Risk Factors and Age-Related Macular Degeneration (AMD). J Optom. 2013; 6(4): 176–184.
5. Pinazo-Duran MD, Gomez-Ulla F, Arias L, et al. Do Nutritional Supplements Have a Role in Age Macular Degeneration Prevention? J Ophthalmol. 2014;901686.
6. Eng Khoo E, Suan Ng H, Yap W-S, et al. .Nutrients for Prevention of Macular Degeneration and Eye-Related Diseases. Antioxidants (Basel). 2019;8(4).