People suffering from a specific type of age-related macular degeneration (AMD) may benefit from a specific combination of vitamins and minerals. Taking these nutritional supplements may help slow the progression of this eye disease. Age-related macular degeneration (AMD) is an eye disease that causes central vision to become blurry. It happens when the macula, the part of the eye that controls sharp, straight-ahead vision, deteriorates with age. The macula is a component of the retina (the light-sensitive tissue at the back of the eye).
When compared to the original AREDS formula, the AREDS2 dietary supplement formula not only reduces the risk of lung cancer due to beta-carotene, but it is also more effective at reducing the risk of AMD progression.
The Age-Related Eye Disease Studies (AREDS and AREDS2) established that dietary supplements can slow progression of age-related macular degeneration (AMD), the most common cause of blindness in older Americans. In a new report, scientists analyzed 10 years of AREDS2 data. They show that the AREDS2 formula, which substituted antioxidants lutein and zeaxanthin for beta-carotene, not only reduces risk of lung cancer due to beta-carotene, but is also more effective at reducing risk of AMD progression, compared to the original formula. A report on the study, funded by the National Institutes of Health, published in JAMA Ophthalmology.
Because beta-carotene increased the risk of lung cancer 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.
Emily Chew
“Because beta-carotene increased the risk of lung cancer 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 Emily Chew, M.D., director of the National Eye Institute’s Division of Epidemiology and Clinical Application and lead author of the study report. “This 10-year data confirms that the new formula is not only safer, but it is also better at slowing AMD progression.”
AMD is a degenerative disease that affects the retina, which is the light-sensitive tissue at the back of the eye. Blindness is caused by the progressive death of retinal cells in the macula, the part of the retina that provides clear central vision. Treatment can slow or reverse vision loss; however, no cure for AMD exists.
The original AREDS study, launched in 1996, showed that a dietary supplement formulation (500 mg vitamin C, 400 international units vitamin E, 2 mg copper, 80 mg zinc, and 15 mg beta-carotene) could significantly slow the progression of AMD from moderate to late disease. However, two concurrent studies also revealed that people who smoked and took beta-carotene had a significantly higher risk of lung cancer than expected.
In AREDS2, begun in 2006, Chew and colleagues compared the beta-carotene formulation to one with 10 mg lutein and 2 mg zeaxanthin instead. Like beta-carotene, lutein and zeaxanthin are antioxidants with activity in the retina. The beta-carotene-containing formation was only given to participants who had never smoked or who had quit smoking.
At the end of the five-year AREDS2 study, the researchers concluded that lutein and zeaxanthin did not increase the risk of lung cancer and that the new formation could reduce the risk of AMD progression by about 26%. Following the completion of the five-year study period, all study participants were given the final AREDS2 formulation, which included lutein and zeaxanthin instead of beta-carotene.
In this new study, the researchers followed up with 3,883 of the original 4,203 AREDS2 participants for an additional five years after the study ended in 2011, collecting information on whether their AMD had progressed to late disease and whether they had been diagnosed with lung cancer.
Even though all of the participants had switched to the lutein and zeaxanthin formula by the end of the study, the follow-up study found that beta-carotene nearly doubled the risk of lung cancer in people who had ever smoked. Lung cancer risk was not increased in those who received lutein/zeaxanthin. Furthermore, after 10 years, the group initially assigned to receive lutein/zeaxanthin had a 20% lower risk of progression to late AMD compared to those initially assigned to beta-carotene.
“These findings validated our decision to switch from beta-carotene to lutein and zeaxanthin in our formula,” Chew said.
