Abstract
Purpose :
No approved treatments exist to slow geographic atrophy (GA) enlargement. The aim was to determine whether closer adherence to a Mediterranean diet (and its individual components) was associated with altered speed of GA enlargement.
Methods :
The design was a cohort study within the AREDS2 clinical trial. The study population comprised 1155 eyes (of 850 participants, mean age 74.9 years) with GA at two or more consecutive visits. GA area was measured by planimetry from color fundus photographs collected at annual study visits. A modified Alternative Mediterranean Diet Index (aMedi) score was calculated for each participant by food frequency questionnaire at baseline. Mixed-model regression analyses of square root GA area were performed according to aMedi. The outcome measure was change in square root of GA area over time.
Results :
Over mean follow-up of 3.1 years from first appearance of GA, the mean GA enlargement rate was 0.282 mm/year (95% confidence interval 0.270-0.293). GA enlargement was significantly slower in those with higher aMedi, at 0.256 mm/year (0.236-0.276), 0.290 (0.268-0.311), and 0.298 (0.280-0.317; P=0.008), for aMedi tertiles 3, 2, and 1, respectively. Of the nine aMedi components considered separately, significant differences in GA enlargement rate were observed for four: whole fruit (P = 0.0004), red meat (P = 0.0002), alcohol (P = 0.006), and monounsaturated: saturated fatty acid (MUFA: SFA; P = 0.040). GA enlargement was slower in those with higher whole fruit, lower red meat, moderate alcohol, and higher MUFA: SFA intake (Table).
Conclusions :
A Mediterranean-type diet was associated with slower GA enlargement. Such diet patterns may therefore lead to clinically meaningful delays in vision loss, particularly for individuals without foveal involvement. Several components contributed most to this protective association, in a pattern that differed from those most associated with decreased progression to GA. Hence, the Mediterranean diet is associated with protection against both faster progression to GA and faster enlargement of GA, but for partially distinct reasons. Understanding the mechanisms responsible may provide insights into the underlying biology and lead to the development of dietary recommendations and nutritional supplements.
This abstract was presented at the 2022 ARVO Annual Meeting, held in Denver, CO, May 1-4, 2022, and virtually.