High-glycemic index carbohydrate increases nuclear factor-kappaB activation in mononuclear cells of young, lean healthy subjects.
BACKGROUND
High-glycemic index diets have been linked to greater risk of cardiovascular disease and type 2 diabetes. Postprandial glycemia within the normal range may promote oxidative stress and inflammatory processes underlying the development of disease.


OBJECTIVE
We explored acute differences in the activation of the inflammatory marker nuclear factor-kappaB after consumption of 2 carbohydrate meals matched for macronutrient and micronutrient composition but differing in glycemic index.


METHODS
After an overnight fast, 10 young, lean healthy subjects were fed in random order 3 meals providing 50 g of available carbohydrate as glucose, white bread, or pasta. Venous blood samples were collected at 0, 1, 2, and 3 h, and nuclear proteins were extracted from mononuclear cells. Changes in nuclear factor-kappaB-p65 proteins were detected by Western blotting. Acute changes in other markers of oxidative stress (nitrotyrosine and soluble intercellular adhesion molecule-1) were also assessed.


RESULTS
The maximum increase in nuclear factor-kappaB activation was similar after the bread meal [mean (+/-SEM) area under the curve: 69 +/- 16% optical density x h] and the glucose challenge (75 +/- 9% optical density x h), but was 3 times higher than after the pasta meal (23 +/- 5% optical density x h) (P < 0.05). Similarly, changes in nitrotyrosine, but not soluble intercellular adhesion molecule-1, were higher after glucose and bread than after pasta (P = 0.01 at 2 h).


CONCLUSIONS
The findings suggest that high-normal physiologic increases in blood glucose after meals aggravate inflammatory processes in lean, young adults. This mechanism may help to explain relations between carbohydrates, glycemic index, and the risk of chronic disease.
Dickinson
Scott
S
Boden Institute of Obesity, Nutrition and Exercise, University of Sydney, NSW, Australia.
Hancock
Dale P
DP
Petocz
Peter
P
Ceriello
Antonio
A
Brand-Miller
Jennie
J
D000293:Adolescent; D000328:Adult; D019540:Area Under Curve; D001786:Blood Glucose / Q000032:analysis / Q000378:metabolism*; D015153:Blotting, Western; D018592:Cross-Over Studies; D004040:Dietary Carbohydrates / Q000493:pharmacokinetics / Q000494:pharmacology*; D005260:Female; D038321:Glycemic Index; D006801:Humans; D007249:Inflammation / Q000378:metabolism; D008297:Male; D009000:Monocytes / Q000378:metabolism; D016328:NF-kappa B / Q000032:analysis / Q000378:metabolism*; D018384:Oxidative Stress / Q000187:drug effects*; D019518:Postprandial Period; D013851:Thinness
D001786:Blood Glucose; D004040:Dietary Carbohydrates; D016328:NF-kappa B