In the news: Array of Nutrients May Impact Risk of AMD Progression

Nutrient Association with Risk of AMD Progression

Age related macular degeneration (AMD) arises from a complex interplay between aging, genetics, and environmental factors, including dietary factors. The AREDS 1 and 2 trials showed that supplementation with specific combinations of antioxidants and minerals decreases progression from intermediate to late AMD, particularly neovascular AMD.

However, it is possible that other nutrients or bioactive components in food could provide additional protection against progression to late AMD. Recent analyses of the AREDS and AREDS2, for example, showed that closer adherence to a Mediterranean dietary pattern, and to its fish component, were highly associated with a slower progression to late AMD, geographic atrophy especially.

Against this backdrop, researchers from the National Eye Institute analyzed data from AREDS 1 and 2 to assess whether dietary intake of various vitamins, minerals and other nutrients are linked to progression to late AMD, progression to large drusen, and whether any nutrients interact with AMD genotypes(1).

Methods

This post hoc analysis included participants with no late AMD at baseline in AREDS (n=4,504) and in AREDS 2 (n=3,738), for a total of 14,135 eyes. Fundus photographs were collected at annual study visits and graded centrally for late AMD. Dietary intake of multiple nutrients was calculated for each participant from food frequency questionnaires.

Results

Over a median follow-up of about 10 years, one third of the eyes advanced to late AMD.

The highest vs. lowest intake of 9 nutrients were significantly (p< 0.0005) associated with decreased risk for late AMD: vitamins A, B6, and C, folate, β-carotene, lutein/zeaxanthin, magnesium, copper, and alcohol.

The highest intake of three nutrients were associated with increased risk: saturated fatty acid, monosaturated fatty acids, and the mono-unsaturated fatty acid oleic acid.

Similar results were seen for geographic atrophy.

For neovascular AMD, 9 nutrients were nominally associated with lower risk: vitamins A and B6, β- carotene, lutein/zeaxanthin, magnesium, copper, omega-3 fatty acid, DHA and alcohol, while the same three fatty acids linked to late AMD progression were also associated with increased risk of progression to neovascular AMD.

These associations were stronger for geographic atrophy than for neovascular AMD. In separate analyses, many of the same nutrients also tended to have protective associations against large drusen development.

The researchers also found that strong genetic interactions exist for some nutrient-genotype combinations, particularly omega 3 fatty acids and CFH (complement factor H) genotype.

Comments

The most consistent finding from over 300 previous prospective studies have included a decreased risk of late AMD associated with higher levels of DHA/EPA and lutein/zeaxanthin intake. The current study lends credence to the protective impact of these long chain fatty acids and carotenoids, but also broadens the array of nutrients linked to slower progression of AMD.

According to the authors, “these data may justify further research into underlying mechanism and randomized trials of supplementation.

References

1. Agrón E, et al. Dietary nutrient intake and progression to late age-related macular degeneration in the Age-Related Eye Disease Studies 1 and 2. Ophthalmol. Online ahead of print Aug. 25, 2020.