Dietary supplements can decrease the the advancement of age-related macular degeneration (AMD), the most common cause of blindness in older Americans, according to the Age-Related Eye Disease Studies (AREDS and AREDS2). Scientists have examined ten years of AREDS2 data in a new report.
They found that the AREDS2 formula, which replaced beta-carotene with antioxidants lutein and zeaxanthin, not only reduced the risk of lung cancer caused by beta-carotene, but also reduced the risk of progression of the disease. AMD compared to the original formula. JAMA Ophthalmology released a report on the study, which was funded by the National Institutes of Health.
“Because beta-carotene increased the risk of lung cancer in 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 he smokes or not,” Emily Chew said. , MD, director of the Division of Epidemiology and Clinical Application at the National Eye Institute (NEI) and lead author of the study report. “These 10-year data confirm that not only is the new formula safer, it is actually better at slowing the progression of AMD.”
The retina, the light-sensitive tissue at the back of the eye, is affected by AMD, which is a degenerative disease. Blindness results from the death of retinal cells in the macula, the part of the retina that provides sharp central vision. Although treatment can reduce or reverse visual loss, there is no cure for AMD.
The first AREDS trial, which began in 1996, found that a dietary supplement formulation (500 mg of vitamin C, 400 international units of vitamin E, 2 mg of copper, 80 mg of zinc and 15 mg of beta-carotene ) could significantly reduce the progression of AMD. from moderate to late disease. People who smoked and took beta-carotene, on the other hand, had a significantly higher risk of lung cancer than expected, according to two separate studies.
Chew and colleagues compared the beta-carotene formulation to a formulation containing 10 mg of lutein and 2 mg of zeaxanthin in AREDS2, which debuted in 2006. Lutein and zeaxanthin, like beta-carotene, are antioxidants that have activity in the retina. Only those who had never smoked or who had recently quit received the beta-carotene-rich formulation.
The researchers determined that lutein and zeaxanthin did not increase the risk of lung cancer during the five-year study period of AREDS2, and that the new formulation may reduce the risk of developing AMD about 26%. After the five-year trial period ended, all study participants received the final formulation of AREDS2, which contained lutein and zeaxanthin instead of beta-carotene.
In this new report, researchers stayed in contact with 3,883 of the original 4,203 AREDS2 participants five years after the study ended in 2011.
They wanted to know if their AMD had gotten worse and if they had been diagnosed with lung cancer. Even though all study participants switched to the formula containing lutein and zeaxanthin at the end of the study, the follow-up study showed that beta-carotene nearly doubled the risk of lung cancer in people who had ever smoked. People who took lutein/zeaxanthin did not have a higher risk of developing lung cancer.
Additionally, after 10 years, the group that initially received lutein/zeaxanthin had a 20% lower chance of developing late-onset AMD than the group that initially received beta-carotene.
“These results confirmed that switching our formula from beta-carotene to lutein and zeaxanthin was the right choice,” Chew said.
The work was funded through the NEI intramural program (EY000546) and contracts (AREDS2 contract HHS-N-260-2005-00007-C; ADB contract NO1-EY-5-0007; AREDS contract NOI-EY-0 -2127, and contract HHS-N-263-2013-00005-C).
The National Institutes of Health’s Office of Dietary Supplements, the National Center for Complementary and Integrative Health, the National Institute on Aging, the National Heart, Lung, and Blood Institute, and the National Institute of Neurological Disorders and Strokes have all contributed funding to the AREDS2 contracts. The research was conducted at the National Institutes of Health Clinical Center.