AREDS and AREDS2: do eye supplements help macular degeneration?

What is AMD, and who was studied?

Age-related macular degeneration, or AMD, affects the macula: the small central part of the retina that helps with detail, such as reading and recognising faces. Early, intermediate and late AMD are different stages; a person may have a different stage in each eye. AREDS focused its main AMD comparison on 3,640 people aged 55–80 with existing AMD, from early to advanced in one eye. AREDS2 enrolled 4,203 people aged 50–85 at higher risk of progression, with large retinal deposits in both eyes or advanced AMD in one eye and large deposits in the other.

Neither study asked whether vitamin A pills improve healthy eyes or treat vitamin A deficiency. For difficulty seeing in the dark, see vitamin A and night vision.

If straight lines newly look wavy or crooked, seek eye-care advice right away; this can be a warning sign of late AMD, but it can have other causes. Sudden inability to see from one or both eyes or sudden severe eye pain needs emergency care. Do not wait to see whether a supplement helps.12345

AREDS: what happened over five years?

The original study randomly assigned people to antioxidants plus zinc and copper, antioxidants alone, zinc and copper alone, or a placebo. In the higher-risk group with intermediate AMD or advanced disease in one eye, researchers estimated that by five years advanced AMD developed in about 28 of every 100 people assigned placebo, compared with about 20 of every 100 assigned the antioxidant-and-zinc combination. That is an estimated difference of 8 percentage points in this group, not a promise for an individual. The original combination contained beta-carotene; it was not the same as a vitamin A pill or today’s AREDS2 formula.13

What did AREDS2 add?

AREDS2 tested whether adding lutein and zeaxanthin, omega-3 fatty acids, or both improved outcomes. Most participants also took an AREDS formulation: the primary placebo was a placebo for the added ingredients, not a comparison with no supplement. In the main analysis, the additions did not significantly reduce progression beyond the background formulation. A separate comparison examined removing beta-carotene and changing zinc; these were different questions from the original trial’s placebo comparison.

The later AREDS2 formula uses lutein and zeaxanthin in place of beta-carotene. Lutein and zeaxanthin are carotenoids, but they do not become vitamin A. The trial does not show that any product containing either ingredient has the same effect.2310

Who might benefit, and who was not shown to?

The US National Eye Institute says the AREDS2 formulation may slow progression for some people with intermediate AMD in one or both eyes. If late AMD affects one eye, it may slow progression in the other eye. It does not prevent AMD from starting, and it has not been shown to stop early AMD becoming intermediate AMD. It does not restore lost vision or establish a general benefit for healthy eyes. The studied formulations also did not prevent or slow cataracts. An eye-care professional can explain the stage in each eye and whether the evidence is relevant.93

What about late dry AMD?

A 2024 re-analysis of eye images from selected AREDS and AREDS2 participants looked at geographic atrophy: areas where light-sensitive tissue has been lost in late dry AMD. When the damage had not yet reached the centre of vision, the analysis found slower movement towards the centre among people who had received the study supplements. It found little benefit where damage already involved the centre, and the overall area of atrophy did not grow significantly more slowly in the comparisons reported. This was a later analysis of scans, not a new trial proving restored sight or the same effect for every person with late AMD. Discuss the specific eye and stage with the treating team.78

The comparisons were different: AREDS compared antioxidants with no antioxidants; AREDS2 compared lutein and zeaxanthin with neither among participants assigned an AREDS formulation without beta-carotene. The analysis was supported by the US National Eye Institute and other NIH bodies; the report also disclosed additional support for individual authors and one author’s industry relationships.7

Why does smoking history change the formula?

The original AREDS formula included beta-carotene. In an AREDS2 secondary comparison among people who were not current smokers, more lung cancers were observed in participants assigned a beta-carotene-containing formula than in those assigned a formula without it: 23 cases (2.0%) versus 11 cases (0.9%); most cases occurred in former smokers. This safety finding fits concerns from other high-dose beta-carotene trials in smokers. It does not mean carrots caused the cancers. The NEI advises current and former smokers to avoid the original beta-carotene formula. Discuss the exact product and smoking history with a clinician. For the earlier cancer-prevention trials and food context, read beta-carotene, smoking and cancer.23

Are all eye supplements the same?

No. A label saying “eye health” or listing lutein does not show that a product matches a trial formulation. The standard AREDS2 formulation in the NEI table contains vitamins C and E, zinc, copper, lutein and zeaxanthin, in specified amounts; it does not contain beta-carotene. Formulations and products vary.

Zinc can cause unwanted effects. Vitamin E can interact with medicines, and a second multivitamin may overlap with an eye product. Bring actual packages and a complete medicine list to an eye-care professional or pharmacist. Use the supplement label guide and the interaction guide to prepare.

The table shows the National Eye Institute’s US daily reference amounts for the original AREDS and AREDS2 formulas. Milligrams (mg) measure mass. International units (IU) express the activity of vitamin E. A vitamin E label may use IU or mg; conversion depends on its form, so 400 IU does not mean 400 mg. These are study/reference amounts, not instructions to start a product. Check the labelled serving size and suggested daily use before comparing: a serving and a day’s suggested use may differ, and other supplements may add the same nutrients. A pharmacist or eye-care professional can help compare the actual label.

AREDS2 also compared a 25 mg zinc version with an 80 mg zinc version. Investigators did not find a statistically significant difference. The comparison did not include a no-supplement placebo group. It therefore does not prove the two amounts are equivalent for everyone. Copper was included in zinc-containing study formulas to reduce the risk of copper-deficiency anaemia. High zinc intake can interfere with copper absorption; added copper is not a guarantee against every risk.

High-dose vitamin E can interact with anticoagulant or antiplatelet medicines, such as warfarin, and may increase bleeding risk. That does not establish the risk for a particular person or product. Do not stop or change prescribed medicine on your own; ask an eye-care professional or pharmacist about the actual label and full medicine list. Read more about zinc and copper and vitamin E and medicine interactions.361112

What should I take away?

The question is not simply whether a vitamin is “good for eyes”. It is which eye condition and stage were studied, which combination was used, and what outcome changed. For vitamin A’s normal role and safety, return to the vitamin A overview.3