Dietary glycemic index and carbohydrate in relation to early age-related macular degeneration.
BACKGROUND
Several dietary factors have been linked to age-related maculopathy (ARM), the early form of age-related macular degeneration, and there is reason to think that dietary carbohydrate may play a role in the development of ARM.


OBJECTIVE
The purpose of the present study was to examine the relation between dietary carbohydrate quality, as measured by dietary glycemic index (GI) or total carbohydrate intake, and ARM.


METHODS
From the Nurses' Health Study, 1036 eyes from 526 Boston-area participants without a previous ARM diagnosis were included in the present study. The presence and degree of ARM were classified by the Age-Related Eye Diseases Study system. Long-term dietary information was based on data from an average of 4 food-frequency questionnaires collected over a 10-y period before the assessment of ARM. With eyes as the unit of analysis, we used a generalized estimating approach to logistic regression to estimate the odds ratios for ARM in a manner that accounted for the lack of independence between the 2 eyes from the same subject.


RESULTS
After multivariate adjustment, dietary GI was related to ARM (specifically to retinal pigmentary abnormalities), whereas total carbohydrate intake was not. The odds ratio for ARM being in the highest tertile of dietary GI (> or =77.0) versus the lowest (<74.6) was 2.71 (95% CI: 1.24, 5.93; P for trend = 0.01). Neither dietary GI nor total carbohydrate intake was related to drusen.


CONCLUSIONS
Our results suggest that dietary GI may be an independent risk factor for ARM.
Chiu
Chung-Jung
CJ
Jean Mayer US Department of Agriculture Human Nutrition Research Center on Aging at Tufts University, 711 Washington Street, Boston, MA 02111, USA.
Hubbard
Larry D
LD
Armstrong
Jane
J
Rogers
Gail
G
Jacques
Paul F
PF
Chylack
Leo T
LT
Hankinson
Susan E
SE
Willett
Walter C
WC
Taylor
Allen
A
D000368:Aged; D000375:Aging / Q000378:metabolism / Q000473:pathology; D001900:Boston / Q000453:epidemiology; D015331:Cohort Studies; D004032:Diet; D004040:Dietary Carbohydrates / Q000009:adverse effects* / Q000378:metabolism* / Q000592:standards; D005260:Female; D038321:Glycemic Index; D006801:Humans; D008137:Longitudinal Studies; D008268:Macular Degeneration / Q000453:epidemiology / Q000209:etiology* / Q000378:metabolism; D008875:Middle Aged; D015999:Multivariate Analysis; D009749:Nutrition Surveys; D016017:Odds Ratio; D015593:Retinal Drusen / Q000453:epidemiology / Q000209:etiology / Q000378:metabolism; D012307:Risk Factors; D011795:Surveys and Questionnaires
D004040:Dietary Carbohydrates