Mediterranean Diet Slows AMD Progression at Every Stage

A focused literature review from researchers distils decades of evidence into clear clinical guidance and the message for optometrists and ophthalmologists is simple: start the conversation about diet at every AMD consultation.

A perspective article accepted by the American Journal of Ophthalmology has synthesised the strongest available evidence on diet and age-related macular degeneration, concluding that a Mediterranean-style eating pattern is associated with slower disease progression across all stages of AMD from early drusen formation through to geographic atrophy (GA).

The paper, authored by researchers at the US National Eye Institute (NEI) and the University of Michigan, draws primarily on data from the landmark Age-Related Eye Disease Studies (AREDS and AREDS2), supplemented by major European and North American epidemiologic cohorts. Lead author Dr Tiarnán Keenan and colleagues argue that the evidence is now robust enough to warrant direct, stage-specific dietary guidance being shared with patients during clinical consultations.

What the data show

Across AREDS participants with early or no AMD, those whose diets most closely resembled a Mediterranean pattern were 21% less likely to develop large drusen over time compared to those with the lowest adherence. For intermediate AMD, the protective association was even stronger, a 23% reduction in risk of progression to late AMD, with the benefit disproportionately skewed toward geographic atrophy (29% risk reduction) compared to neovascular AMD (16%).

Component-level analysis revealed that not all dietary elements carry equal weight. For intermediate AMD, fish intake was the single strongest protective factor, with participants in the highest intake quartile showing a 31% decreased risk of late AMD progression. High vegetable intake followed, associated with a 23% reduced risk, while red meat was the most clearly harmful component, linked to a 20% increased risk.

For patients with established GA, the dietary emphasis shifts. The AREDS2 data showed mean GA enlargement rates were approximately 15% slower in the highest Mediterranean diet adherence tertile compared to the lowest and notably, it was whole fruit and reduced red meat intake that drove most of this benefit, not fish. A Mediterranean diet was also associated with roughly 30% slower GA progression towards the fovea, with vegetable intake identified as the most influential single component.

Supplements remain essential but not sufficient

The paper reinforces the role of the AREDS2 supplement formulation (vitamin C 500 mg, vitamin E 400 IU, zinc oxide 80 mg, copper 2 mg, lutein 10 mg, zeaxanthin 2 mg) for patients with intermediate or advanced AMD. Crucially, the authors emphasise that dietary benefit and supplementation are complementary rather than interchangeable. Supplements preferentially reduce risk of neovascular AMD, while a Mediterranean diet shows stronger protective associations for GA meaning both strategies are required to address the full spectrum of late AMD risk.

The paper also highlights a particularly relevant finding for GA management: post-hoc AREDS analyses suggest the current AREDS2 formulation may slow progression of extrafoveal GA towards the foveal centre by approximately 50%, a figure with meaningful implications for preserving central vision in this difficult-to-treat group. The authors note this finding requires prospective confirmation, and have flagged plans for a dedicated trial within the AREDS3 programme.

Clinical implications for Australian practice

The authors acknowledge the persistent gap between evidence and real-world adherence. Data from the Rotterdam Study found that only 4% of adults met recommended intake quantities for all three key protective food groups vegetables, fruit, and fish. Similar shortfalls are documented across North American and European populations, and there is little reason to assume Australian patients fare better.

For busy optometry and ophthalmology practices, the paper's emphasis on "teachable moments" is particularly useful. Behavioural science evidence suggests patients are most receptive to lifestyle change at the point of a new or worsening diagnosis precisely when practitioners have the patient's full attention.

The authors are explicit that the Mediterranean diet need not be prescribed in its culturally specific form. Patients from diverse backgrounds, including those common in Australian clinical settings, can apply the same underlying principles: high plant food intake, regular fish consumption, minimal processed foods and red meat within their own traditional dietary patterns. Evidence for protective effects has also been reported for Asian and Japanese dietary patterns that share these features.

The bottom line for clinicians

The paper's summary recommendations by AMD stage are clear: a Mediterranean diet for all stages; AREDS2 supplements added from intermediate AMD onwards; strong emphasis on fish for intermediate AMD; and a shift toward abundant fruit and vegetables, reduced red meat, and alcohol avoidance for GA. A predominantly plant-based diet appears particularly important at the GA stage.

Given the absence of disease-modifying therapies for early or intermediate AMD, and the limited options for atrophic disease, dietary counselling represents one of the few genuinely actionable interventions available at the point of diagnosis. The authors frame it plainly: "It may never be too early or too late to adopt a healthy diet."