Dietary nitrate could help stop the progression of age-related macular degeneration (AMD), according to recent research.
Dr Geoffrey Broadhead, from the US National Eye Institute and the Save Sight Institute in Sydney, and colleagues examined the association between dietary nitrate intake and AMD progression.
dietary nitrate intake was associated with a reduced risk for progression to late AMD
They used data from the prospective Age-Related Eye Disease Study (AREDS) and AREDS2 randomised clinical trial cohorts and extended follow-up studies. Data were included for 7,788 participants in the combined AREDS/AREDS2 cohort, with 13,511 eligible eyes.
The patients in both trials had AMD that had not reached the late stage of the disease in at least one eye.
The researchers found that in the combined AREDS/AREDS2 cohort, dietary nitrate intake was associated with a reduced risk for progression to late AMD (hazard ratio, 0.77 for quartile four versus one of intake); the risks for geographic atrophy (GA) and neovascular AMD (nAMD) were also reduced (hazard ratios, 0.71 and 0.85, respectively).
“The findings of this cohort study suggest that nitrate intake was associated with a decreased risk of progression to late AMD, including both late AMD subtypes,” the authors concluded.
“This association persisted even after accounting for lutein and zeaxanthin intake as a potential confounder and was strongest among individuals with lower adherence to a fruit and vegetable–rich diet pattern. A protective association was also seen against the development of large drusen, suggesting that the benefit of dietary nitrates may extend across a wide spectrum of AMD severities,” the authors said.
However, the authors did not see evidence that supported adding nitrate as a supplement. They explained that the study outcome was “attributed to plant-based dietary patterns in general, such as a Mediterranean diet”.
1. Broadhead G.K., Agrón E., Peprah D., et al., Association of dietary nitrate and a Mediterranean diet with age-related macular degeneration among US adults. The Age-Related Eye Disease Study (AREDS) and AREDS2. JAMA Ophthalmol. Published online December 22, 2022. doi:10.1001/jamaophthalmol.2022.5404.