Glycemic index and glycemic load in relation to food and nutrient intake and metabolic risk factors in a Dutch population.

BACKGROUND: Previous studies on the glycemic index (GI) and glycemic load (GL) reported inconsistent findings on their association with metabolic risk factors. This may partly have been due to differences in underlying dietary patterns.

OBJECTIVE: We aimed to examine the association of GI and GL with food and nutrient intake and with metabolic risk factors including blood glucose, insulin, lipids, and high-sensitivity C-reactive protein (CRP).

DESIGN: The study entailed cross-sectional analyses of data from 2 joint observational studies, the CoDAM Study and the Hoorn Study.

RESULTS: In total, 974 subjects aged 42-87 y were included in the study. The mean (+/-SD) GI was 57 +/- 4 and the mean GL was 130 +/- 39. Dairy products, potatoes and other tubers, cereal products, and fruit were the main predictive food groups for GI. GL was closely correlated with intake of total carbohydrates (r(s) = 0.97), which explained >95% of the variation in GL. After adjustment for potential confounders, GI was significantly inversely associated with HDL cholesterol and positively associated with fasting insulin, the homeostasis model assessment index of insulin resistance, the ratio of total to HDL cholesterol, and CRP. No association was observed between GL and any of the metabolic risk factors, except for a borderline significant positive association with CRP.

CONCLUSIONS: In this population, a low-GI diet, which is high in dairy and fruit but low in potatoes and cereals, is associated with improved insulin sensitivity and lipid metabolism and reduced chronic inflammation. GL is highly correlated with carbohydrate intake and is not clearly associated with the investigated metabolic risk factors.