Two studies have found that a combination of vitamin C, E, beta-carotene, zinc and copper could reduce the risk of age-related macular degeneration (AMD).
The clinical trials were conducted by the NIH National Eye Institute for a five year period, finding that supplementation with the key nutrients could delay the onset of AMD in elderly adults.
They also found that the progression of AMD for those who already have it could be slowed by supplementing with the nutraceutical mix.
The first of the two studies, named AREDS by the NIH, found that the vitamin and mineral combination didn't prevent AMD's onset, but reduce the risk of disease progression by 25%.
To follow up this positive results, AREDS2 was conducted, but instead of beta-carotene, the researchers incorporated lutein and zeaxanthin — two other common carotenoids.
They found that this swap reduced the progression risk even further, and was less risky for those who had previously smoked, as excessive beta-carotene consumption can be linked to lung cancer in former smokers.
After a ten year follow-up assessment post-AREDS2, the benefits on participants' quality of vision was still observed.
Preserving vision with lutein and zeaxanthin
To further explore the benefits of lutein and zeaxanthin on eye health, researchers looked into their impact on geographic atrophy, an advanced form of AMD.
Geographic atrophy usually results in lesions inside the retina, which can damage an affected individual's vision.
It was found that, for those who had geographic atrophy away from the centre of the macula, lutein and zeaxanthin supplementation slowed the progression of geographic atrophy.
This means that the carotenoids could help preserve central vision in users.
Director of the Division of Epidemiology and Clinical Applications at the National Eye Institute, Dr Emily Chew, commented: “We are excited that these post-hoc analyses demonstrate a potential for the use of AREDS2 supplements in patients who have developed the late form of dry AMD, geographic atrophy,”
“These are exploratory analyses and we anticipate conducting a prospective study to test this potential new indication for AREDS2 supplements.”