Study: Supplements May Slow Progression of Age-Related Macular Degeneration
Over a period of 10 years, substituting antioxidants lutein and zeaxanthin for beta-carotene was found to be more effective at lowering the risk of AMD progression.
Dietary supplements may help to slow the progression of age-related macular degeneration (AMD), which is the most common cause of blindness in older Americans, according to the Age-Related Eye Disease Studies (AREDS and AREDS2), which were funded by the National Institutes of Health and published in JAMA Ophthalmology.
AREDS2 data showed that over a period of 10 years, substituting antioxidants lutein and zeaxanthin for beta-carotene was more effective at lowering the risk of AMD progression versus the original formula.
The original AREDS study used a dietary supplement formulation of 500 mg vitamin C, 400 international units of vitamin E, 2 mg copper, 80 mg zinc, and 15 mg beta-carotene. Additionally, 2 concurrent studies showed that individuals who smoked and took beta-carotene had a significantly higher risk of lung cancer than expected.
“Because beta-carotene increased the risk of lung cancer for current smokers in two NIH-supported studies, our goal with AREDS2 was to create an equally effective supplement formula that could be used by anyone, whether or not they smoke,” said lead study author Emily Chew, MD, director of the Division of Epidemiology and Clinical Application at the National Eye Institute (NEI), in the press release. “This 10-year data confirms that not only is the new formula safer, it is actually better at slowing AMD progression.”
Chew and colleagues compared the beta-carotene formulation to 10 mg lutein and 2 mg zeaxanthin in the AREDS2 study. Beta-carotene was only administered to participants who had never smoked or who had quit smoking.
The researchers observed that by the end of the 5-year AREDS2 study period, lutein and xeaxanthin did not increase the risk for lung cancer and that the new formation could lower the risk of AMD progression by approximately 26%. The study participants were also offered the final AREDS2 formation consisting of lutein and zeaxanthin instead of beta-carotene.
The new report followed up with 3883 out of the original 4203 AREDS2 participants after an additional 5 years from the end of the AREDS2 study in 2011. The researchers analyzed whether the patients’ AMD progressed to late disease and whether they had been diagnosed with lung cancer.
The findings showed that beta-carotene increased the risk of lung cancer for individuals who smoked in their lifespan by double, however, there was no increased risk of lung cancer in those who were administered lutein/zeaxanthin. Additionally, after 10 years, the group originally administered lutein/zeaxanthin had a 20% lower risk of progression to late AMD versus individuals originally assigned to receive beta-carotene.
“These results confirmed that switching our formula from beta-carotene to lutein and zeaxanthin was the right choice,” Chew said in the press release.
NIH study confirms benefit of supplements for slowing age-related macular degeneration. NIH National Eye Institute. June 2, 2022. Accessed June 7, 2022. https://www.nei.nih.gov/about/news-and-events/news/nih-study-confirms-benefit-supplements-slowing-age-related-macular-degeneration