AREDS Studies Revisited
Friday, February 10, 2017
The American Society for Nutrition just published a review article from the Moran Eye Center, University of Utah School of Medicine, titled "The Age-Related Eye Disease 2 Study: Micronutrients in the Treatment of Macular Degeneration."
The purpose was to examine the science behind the nutritional factors included in this and other interventional studies and the reasons for considering their inclusion to lower the rate of AMD progression.
The background discussion
“Age-related macular degeneration (AMD) is one of the leading causes of vision loss [notice they did not say blindness] in the elderly in the country.
“With an increasingly aged population worldwide, the need for the prevention of AMD is rising. Multiple studies investigating AMD with the use of animal models and cell culture have identified oxidative stress-related retinal damage as an important contributing factor".
In general, diet is an excellent source of the antioxidants, vitamins and minerals necessary or healthy living; moreover, the general public is often receptive to recommendations made by physicians and health care workers regarding diet and supplements as a means of empowering themselves to avoid common and worrisome ailments such as AMD, which has made epidemiologists and clinicians enthusiastic about dietary intervention studies.
“A wide variety of nutrients, such as minerals, vitamins, omega-3 fatty acids and various carotenoids have been associated with reducing the risk of AMD."
Micronutrient discussion high points
“Initial results from the first AREDS study indicated that supplementation with antioxidants (B-carotene and vitamins C and E) and zinc was associated with a reduced risk of AMD progression. The AREDS2 follow-up study, designed to improve upon the earlier formulation, tested the addition of lutein, zeaxanthin and omega-3 fatty acids EPA and DHA.”
The review looked at vitamins including C, E, B6, B12 and folic acid. They reported that low vitamin C levels were associated with an increased risk of AMD, but high concentrations were not protective and did not significantly affect the progression of AMD.
The review discusses vitamin E and its role in controlling oxidative stress. The authors suggested that, “deprivation of vitamin E could lead to lipofuscin accumulation, retinal damage and loss of photoreceptors. Vitamin E deficiency accelerates with age, and epidemiologic studies also suggest a beneficial effect of vitamin E on the progression of AMD. Other studies have shown that vitamin E has no adverse or protective effect on early AMD incidence and progression.”
The review also focused on the 2009 study that indicated daily supplementation with folic acid, vitamins B6 and B12 decreased the risk of AMD in women. This particular study was supported by a 10-year follow-up in the Blue Mountains Eye Study, suggesting that deficiencies of folic acid and B12 increase AMD risk.
They did a great job of separating the singlet oxygen nullifying functions of the hydrocarbon carotenoid, B-carotene, and the macular pigment density enhancing / blue light-protecting xanthophyll carotenoids lutein and zeaxanthin. They pointed out that under certain conditions, B-carotene can have pro-oxidant activity and act as a tumor promoter. They also discussed the competitive absorption of carotenes over xanthophyll carotenoids.
As for zinc, they reported again that the group in the AREDS2 study formulation assigned with low zinc compared to the high amount of zinc included in the first ARED study showed the same results. Copper was added as an afterthought to the AREDS formulation to balance the large amount of zinc. [Given that 25 mg of zinc proved to be as effective as 80 mg, far smaller amounts of copper is required for biochemical balance, depending on the quality of the zinc included in the formulation.]
They reported that no significant AREDS2 correlation was established for omega-3 EPA and DHA supplementation with the progression of AMD. However, in contrast with the AREDS2 result, the Nutritional AMD Treatment-2 study, in which patients were administered 840 mg DHA and 270 mg EPA for three years, suggested that the choroidal neovascularization incidence was markedly reduced in DHA-supplemented patients.
Based on the AREDS2 study results, the AREDS2 formulation with 10 mg lutein and 2 mg zeaxanthin is now the standard of care for reducing the probability of advanced AMD patients with substantial risk factors for progression to severe visual loss. The AREDS2 failed to show that fish oil supplements had any benefits, and the B-carotene in the original AREDS formula is no longer recommended because of potential lung cancer risks, as well as the absorption competition between B-carotene and lutein and zeaxanthin.
They pointed out that ARED2 was not designed to determine whether or not individuals without signs of symptoms of AMD should take supplements, but clinicians should definitely advise everyone concerned about developing AMD to practice a healthy, vigorous lifestyle by avoiding smoking, getting regular physical activity and maintaining a diet rich in colorful fruits and vegetables and oily fish.
They also discussed other nutritional interventions against AMD and the unlikelihood of there ever being a study on the scale of the AREDS2 to support their efficacy. A few sentences were devoted to the growing concern among clinicians that excessive intake of fat-soluble and water-soluble vitamins and micronutrients and minerals may be associated with toxicity, including undesirable interactions with pharmaceutical drugs.
Therefore, they stressed the importance of practitioners educating themselves and patients about the benefits of supplements and why a certain supplement is being recommended for individual use, as well as the risks involved when supplements are consumed in excess.
Because clinicians and the public should be concerned about potential micronutrient toxicity, Biosyntrx makes it a point of never exceeding the Academy of Sciences’ Institute of Medicine safe upper limit (UL) of the micronutrients included in our multiple products.
Ellen Troyer with Spencer Thornton, MD, David Amess and the Biosyntrx staff
DALK Cannula M8201