Age-Related Eye Disease Studies (AREDS & AREDS2)
The original Age-Related Eye Disease Study (AREDS) performed by the US National Institute of Health (NIH) started in 1996. It involved over 4,000 participants and found that specific high doses of Vitamins C and E, anti-oxidant carotenoid beta-carotene and the minerals zinc and copper (known as the AREDS formulation) can help slow the progression to advanced Age-related Macular Degeneration (AMD).
- Beta-carotene (15mg)
- Vitamin C (500mg)
- Vitamin E (400IU)
- Zinc (80mg)
In this first AREDS trial, the risk of developing advanced AMD was reduced by 25% in those who took the AREDS formulation. The trial lasted for five years until 2001 and was placebo-controlled, meaning the comparison group took a tablet that did not contain the AREDS formulation.
The only contradictions found during the study were that high dose beta-carotene leads to an increased risk of lung cancer in smokers or anyone who has smoked previously. High doses of zinc can cause minor gastro-intestinal disturbances and lower copper levels in the body (this is why the AREDS formula contains copper).
Since then, other ingredients thought to be beneficial to the eyes have been tested. The AREDS2 trial started in 2006 and again involved more than 4,000 participants. Over the next five years, it examined whether these other ingredients could improve the original AREDS formulation. They are two carotenoid vitamins from plant sources, lutein and zeaxanthin and EPA/DHA (omega 3 fatty acids), such as those found in oily fish. The trial also tested the removal of beta-carotene and lower zinc levels than the original formulation as these can cause side effects in some people.
In AREDS2, randomly selected groups took one of the following combinations every day for five years:
- 10mg lutein and 2mg zeaxanthin
- 1,000mg EPA/DHA (omega 3 essential fatty acids)
- 10mg lutein and 2mg zeaxanthin and 1,000mg EPA/DHA
Then each group was further split and people ALSO took one of the following four:
- Original AREDS formulation
- AREDS formulation with no beta-carotene
- AREDS formulation with reduced zinc
- AREDS formulation with no beta-carotene and reduced zinc
The researchers measured the progression to advanced AMD by examining images of the back of the eye for yellow deposits called drusen or by commencing treatment for advanced AMD. The results were announced during a Special Session at ARVO (Association for Research in Vision and Ophthalmology) on May 5th 2013.