Dietary compound score and risk of age-related macular degeneration in the age-related eye disease study.
OBJECTIVE
Because foods provide many nutrients that may interact to modify risk for multifactorial diseases such as age-related macular degeneration (AMD), we sought to develop a composite scoring system to summarize the combined effect of multiple dietary nutrients on AMD risk. This has not been done previously.


METHODS
Cross-sectional study.


METHODS
From the 4003 participants in the Age-Related Eye Disease Study (AREDS), there were 7,934 eyes included in this study.


METHODS
Considering dietary intakes of vitamins C and E, zinc, lutein/zeaxanthin, docosahexaenoic acid, eicosapentaenoic acid, and low-dietary glycemic index (dGI) from AREDS baseline information, we assigned each nutrient a percentile rank score then summed them into a compound score for each participant. Using eye as the unit of analysis, we evaluated the association between the compound score and risk of prevalent AMD. Validation, fitness, and performance of the model were evaluated using bootstrapping techniques, adjusted quasi-likelihood under the independence model criterion, and the c-index, respectively.


METHODS
Stereoscopic fundus photographs of the macula were taken and graded at baseline using the AREDS protocol and AMD Classification System.


RESULTS
Our results showed that higher compound scores were associated with lower risk for early AMD, indicated by drusen, and advanced AMD. Validation analyses indicated that these relationships are robust (the average 50-time bootstrapping per quartile odds ratios = 0.727, 0.827, and 0.753, respectively, for drusen, and 0.616, 0.536, and 0.572, respectively, for advanced AMD). Model selection analyses suggested that the compound score should be included, but that measures of dietary beta-carotene should not be included.


CONCLUSIONS
We found that consuming diets that provide low dGI and higher intakes of these nutrients were associated with the greatest reduction in risk for prevalent drusen and advanced AMD, whereas dietary beta-carotene did not affect these relationships. These findings warrant further prospective studies.


BACKGROUND
Proprietary or commercial disclosure may be found after the references.
Chiu
Chung-Jung
CJ
Jean Mayer United States Department of Agriculture Human Nutrition Research Center on Aging, Department of Ophthalmology School of Medicine, Tufts University, 711 Washington Street, Boston, MA 02111, USA. cj.chiu@tufts.edu
Milton
Roy C
RC
Klein
Ronald
R
Gensler
Gary
G
Taylor
Allen
A
D000368:Aged; D000369:Aged, 80 and over; D001205:Ascorbic Acid / Q000008:administration & dosage; D003430:Cross-Sectional Studies; D004032:Diet; D004034:Diet Surveys; D019587:Dietary Supplements; D004281:Docosahexaenoic Acids / Q000008:administration & dosage; D015118:Eicosapentaenoic Acid; D002149:Energy Intake; D005231:Fatty Acids, Unsaturated / Q000008:administration & dosage; D005247:Feeding Behavior; D005260:Female; D038321:Glycemic Index; D006801:Humans; D014975:Lutein / Q000008:administration & dosage; D008268:Macular Degeneration / Q000453:epidemiology* / Q000209:etiology; D008297:Male; D008875:Middle Aged; D015593:Retinal Drusen / Q000453:epidemiology* / Q000209:etiology; D018570:Risk Assessment; D014810:Vitamin E / Q000008:administration & dosage; D024341:Xanthophylls / Q000008:administration & dosage; D065146:Zeaxanthins; D015032:Zinc / Q000008:administration & dosage
D005231:Fatty Acids, Unsaturated; D024341:Xanthophylls; D065146:Zeaxanthins; D014810:Vitamin E; D004281:Docosahexaenoic Acids; D015118:Eicosapentaenoic Acid; D015032:Zinc; D001205:Ascorbic Acid; D014975:Lutein