Summary of AREDS 2 Results
Analyses of the AREDS2 data showed:
Primary, secondary and subgroup analysis demonstrated no additional beneficial or harmful effects of DHA + EPA (omega 3) for treatment of AMD.
Primary analysis demonstrated no additional beneficial or harmful effects of lutein + zeaxanthin for treatment of AMD.
Daily supplementation with lutein & zeaxanthin, omega 3 (DHA & EPA), or lutein, zeaxanthin & omega 3 (DHA+EPA) in addition to the original AREDS formulation showed no statistically significant overall effect on progression to advanced AMD or changes in visual acuity compared to the original AREDS formula alone.
These results were somewhat of a surprise to most, as other studies and data extrapolation appeared to show that both would be of benefit and offer an additional protective effect in slowing the progression of AMD.
Analysis of the groups that took lutein + zeaxanthin (compared to those that did not) yielded other results worth considering.
Participants with the poorest dietary intake of lutein + zeaxanthin were about 25% less likely to develop advanced AMD when supplemented with lutein + zeaxanthin
Serum (blood) levels of lutein + zeaxanthin were lower in the group who also took beta-carotene meaning there may be competitive absorption of carotenoids in the body.
Participants who received lutein + zeaxanthin and the AREDS formula with no beta-carotene were slightly less likely to progress to advanced AMD than those who received no lutein and zeaxanthin but the original AREDS formula with beta-caotene.
These observations have several implications for supplement use in AMD.
- Supplementation is even more important for people with poor diets
- Care should be taken recommending a supplement which contains a mix of carotenoids as this may be counterproductive. So where a supplement contains the main carotenoids of lutein and zeaxanthin others such as beta-carotene, meso-zeaxanthin or astaxanthin should be avoided.
- Lutein + zeaxanthin could be a suitable substitute for beta-carotene in the original AREDS formula
With regard to beta-carotene the study confirmed that taking the high dose of beta-carotene used in the original AREDS formula is linked to an increased risk of lung cancer in ex-smokers (as well as smokers). Finally, while there appeared to be little difference in the results for the sub-groups receiving higher and lower doses of zinc, there was insufficient evidence to suggest changing the original AREDS formula.
In summary, when announcing these results the team ended by suggesting that the new AREDS2 formulation would be suitable for everyone and should be:
- Vitamin C (500mg)
- Vitamin E (400IU)
- Lutein (10mg)
- Zeaxanthin (2mg)
- Zinc (25mg)