Antioxidant Supplement Could Slow Progression of Blinding Eye Disease

AREDS2 supplements require caution, despite promising results, experts warn.

A mixture of antioxidants appears to slow the progression of an eye disorder called dry age-related macular degeneration (AMD), even once it’s reached the advanced stage.

AMD is a condition that, if untreated, can eventually lead to blindness. There is no cure for the disease and currently available pharmaceutical treatments can be expensive and invasive.

55 Percent Reduction in Disease Progression

Two major clinical trials, known as AREDS and AREDS2, examined the association between particular antioxidants and AMD progression. Those trials identified six supplements linked to eye health and slow  AMD progression.

The AREDS trial showed that a supplement combining antioxidants (vitamins C and E, plus beta-carotene) with zinc and copper could slow the advancement of AMD from intermediate to late stages. The AREDS2 study found that replacing beta-carotene with lutein and zeaxanthin (naturally occurring carotenoids) enhanced the supplement’s effectiveness while reducing potential risks.

While those trials found taking the six nutrients reduced risk of progression from intermediate to advanced AMD by 25 percent, there was no indication in the original AREDS study that they could slow progression once the disease had advanced to geographic atrophy, the most advanced stage of dry AMD.

A follow-up post-hoc analysis of the AREDS/AREDS2 clinical trials aimed to find evidence that the antioxidant formulation could help even in cases of advanced dry AMD. The findings demonstrate that over a three-year period, the eyes of patients with geographic atrophy who took AREDS antioxidants showed only 50.7 microns of disease progression—the physical distance the condition advanced over that period of time—compared with 72.9 microns in the eyes of those given a placebo. This is a 55 percent reduction in disease progression without pharmaceutical intervention.

AREDS2 Supplements–Use With Caution: Expert

While the ingredients making up the AREDS2 supplement are generally safe and well-tolerated, caution is necessary when using it, Dr. Yu Hyon Kim, attending physician, retina and assistant professor of ophthalmology and visual sciences at Montefiore Einstein Medical Center in New York, told The Epoch Times.

“Especially if you are also taking other medications or supplements containing the same ingredients or if you have kidney or liver conditions,” he said. “For example, high-dose vitamin C may increase the risk of kidney stones, particularly in patients with pre-existing kidney problems,” Kim noted.

High-dose vitamin E may increase the risk of bleeding, which is why patients on blood thinners like Coumadin or Plavix should be closely monitored. Zinc can also interact with certain antibiotics, such as quinolones (broad-spectrum antibiotics) and tetracyclines (used to treat pneumonia and other respiratory tract infections), reducing their absorption and effectiveness, he added.

“Additionally, some blood pressure medications, including ACE inhibitors and thiazides, may decrease zinc absorption, potentially diminishing the effectiveness of the AREDS 2 supplement,” Kim said.

Although, he said, overall, he considers the AREDS2 formulation to be a safe and potentially effective way to reduce the risk of developing advanced AMD.

“It is one of the few, if not the only, dietary supplements with robust scientific evidence supporting its ability to prevent a devastating disease,” he said. “Previously, we understood that AREDS2 supplements could help reduce the risk of progression to neovascular (wet) AMD.” However, he added, this new finding shows that the benefits also extend to delaying the progression of dry AMD.

Kim said he recommends this supplement formulation only to his at-risk patients. “It is important to note that the AREDS 2 study involved patients who met specific criteria, namely intermediate or late AMD.” There is still no evidence that AREDS2 supplementation will prevent AMD in people with no signs of the disease, Kim noted.

AMD Is a Leading Cause of Blindness

AMD is a leading cause of blindness in Americans over 50, typically affecting people 55 and older.

2 Main Types of AMD

• Dry AMD: The most common type, it gradually damages light-sensitive cells in the macula.
• Wet AMD: Less common but more severe, it involves abnormal blood vessel growth and fluid leakage.

Dry AMD currently has no available treatment. Wet AMD can be treated with injections, which suppress vascular endothelial growth factor (VEGF), called anti-VEGF agents. High levels of VEGF in the eye are linked to abnormal blood vessel growth that causes vision loss.