Abstract
Purpose :
There is growing evidence of the importance of nutrition in age-related macular degeneration (AMD), but few studies have explored associations with folate and B vitamins. No effective therapeutic strategy for geographic atrophy (GA) is available and prevention could be of great value. We hypothesized that higher dietary intake of folate and B vitamins could reduce progression to GA, and that these associations could be modified by genetic susceptibility.
Methods :
Among 2525 subjects (4663 eyes) in the Age-Related Eye Disease Study, 405 subjects (528 eyes) progressed to GA over 13 years (mean follow up: 8.7 years). Folate and B vitamins were log transformed and calorie-adjusted separately for men and women. Ten loci in seven AMD genes (CFH, ARMS2, C2, C3, CFB, COL8A1, and RAD51B) were examined. Survival analysis was used to assess associations between incident GA and dietary intake of folate and B vitamins. Interaction effects between these nutrients and genetic variation on AMD risk were also evaluated.
Results :
There was a lower risk of progression to GA with increasing intake of thiamin, riboflavin, and folate after adjusting for age, sex, and total energy intake (P trend=0.01, 0.03, and 0.001, respectively). After adjustment for demographic, behavioral, ocular, and genetic covariates, trends remained significant for folate (hazard ratio [HR]: 0.70; 95% confidence interval [CI]: 0.52-0.95; P trend=0.007) and were borderline for thiamin (P trend=0.05). Riboflavin did not retain statistical significance in these multivariate analyses (P trend=0.20). Dietary folate intake was significantly associated with a lower risk of incident GA among subjects homozygous for the C3 R102G non-risk genotype (CC) (HR: 0.43; 95% CI: 0.27-0.70; P =0.0005), but subjects carrying the risk allele (G) did not appear to benefit (HR: 0.94; 95% CI: 0.62-1.42; P=0.76). Neither folate nor any B vitamin was significantly associated with neovascular AMD.
Conclusions :
Our study suggests that high dietary folate intake is associated with a reduced risk of progression to GA. This benefit might be modified by genetic susceptibility, particularly related to C3 R102G. Eating a healthy diet rich in folate could contribute to the reduction and prevention of visual loss due to atrophic macular degeneration.
This is an abstract that was submitted for the 2016 ARVO Annual Meeting, held in Seattle, Wash., May 1-5, 2016.