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  • Mediterranean Diet Slows GA

    By Jean Shaw
    Selected by Andrew P. Schachat, MD
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    Journal Highlights

    Ophthalmology Retina, September 2022

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    Can diet have an effect on the speed at which the area of geographic atrophy (GA) enlarges? Agrón et al. set out to determine whether close adherence to a Mediterranean diet could help answer this question. They found that the diet was associated with slower GA enlargement, particularly in those who had a higher intake of whole fruits and monounsaturated fats and a lower intake of red meat and alcohol.

    For this post hoc analysis of the Age-Related Eye Disease Study 2 (AREDS2), the researchers evaluated 1,155 eyes (850 participants) with GA at two or more visits. The area of GA was measured from color fundus pho­tographs taken at each annual visit. An alternative Mediterranean diet index (aMedi) was calculated for each partic­ipant, using a food frequency ques­tionnaire. The intake of nine dietary components was assessed (whole fruits, vegetables, whole grains, nuts, legumes, fish, red meat, alcohol, and the ratio of monounsaturated fatty acid to saturat­ed fatty acid [MUFA:SFA]). For each component, sex-specific intake quar­tiles (1-4) were calculated, with quartile 4 representing the lowest intake of red meat, moderate intake of alcohol, and the highest intake of MUFAs and the other components. Mixed-model re­gression was performed for the square root of the GA area. The main outcome measure was the change in square root of the GA area over time.

    Over a mean follow-up of 3.1 years, the mean rate in GA enlargement was .282 mm/year (95% confidence interval [CI], .270-.293). For those in groups 1, 2, and 3, the mean rates of enlargement were .298 (.280-317), .290 (.268-.311), and .256 (.236-.276) mm/year, respec­tively, suggesting a dose-response to the diet. With regard to individual dietary components, GA enlargement occurred more slowly in those who ate more whole fruits and more quickly in those who ate greater amounts of red meat. No statistically significant interaction was observed for fish intake, in contrast to earlier AREDS2 dietary evaluations.

    In their discussion, the authors note that the difference in enlargement rates “could be clinically important over the long time periods taken for GA to enlarge.” Given the paucity of cur­rent treatments for GA, they add that dietary modification “might represent an important strategy to delay disease progression in patients affected by GA.”

    The original article can be found here.