Dietary glycemic index and the risk of age-related macular degeneration

Am J Clin Nutr. 2008 Oct;88(4):1104-10. doi: 10.1093/ajcn/88.4.1104.

Abstract

Background: Dietary factors are known risk factors for age-related macular degeneration (AMD) -- the leading cause of visual loss among persons aged > or =65 y. High-glycemic-index diets have been hypothesized as a risk factor for AMD, but prospective data are unavailable.

Objective: The objective was to examine the association between dietary glycemic index and the 10-y incidence of AMD in the Blue Mountain Eye Study population.

Design: This was a population-based cohort study with 3,654 participants (> or =49 y) examined at baseline (1992-1994); 2,335 patients were reexamined after 5 y and 1952 after 10 y. The Wisconsin System was used to grade 10-y incident early and late AMD from retinal photographs. A food-frequency questionnaire was used to collect dietary information at baseline, and an Australian database was used to calculate the mean glycemic index.

Results: Over 10 y, 208 of 1,810 persons (cumulative incidence: 14.1%) developed early AMD. After age, smoking, other risk factors, and dietary constituents were adjusted for, a higher mean dietary glycemic index was associated with an increased 10-y risk of early AMD in a comparison of quartiles 1 and 4 [relative risk (RR): 1.77; 95% CI: 1.13, 2.78; P for trend = 0.03]. Conversely, a greater consumption of cereal fiber (RR: 0.68; 95% CI: 0.44, 1.04; P for trend = 0.05) and breads and cereals (predominantly lower glycemic index foods such as oatmeal) (RR: 0.67; 95% CI: 0.44, 1.02; P for trend = 0.03) was associated with a reduced risk of incident early AMD. No relation was observed with late AMD.

Conclusions: A high-glycemic-index diet is a risk factor for early AMD -- the recognized precursor of sight-threatening late AMD. Low-glycemic-index foods such as oatmeal may protect against early AMD.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aged
  • Cohort Studies
  • Dietary Carbohydrates / administration & dosage*
  • Dietary Carbohydrates / classification
  • Dietary Carbohydrates / metabolism
  • Dietary Fiber / administration & dosage*
  • Dietary Fiber / classification
  • Dietary Fiber / metabolism
  • Feeding Behavior*
  • Female
  • Follow-Up Studies
  • Glycemic Index*
  • Humans
  • Incidence
  • Macular Degeneration / epidemiology*
  • Macular Degeneration / etiology
  • Macular Degeneration / prevention & control
  • Male
  • Middle Aged
  • Multivariate Analysis
  • New South Wales / epidemiology
  • Prospective Studies
  • Risk Factors
  • Surveys and Questionnaires

Substances

  • Dietary Carbohydrates
  • Dietary Fiber