Effect of dietary antioxidants on postprandial endothelial dysfunction induced by a high-fat meal in healthy subjects.
BACKGROUND
Persons following current dietary guidelines have a lower risk of mortality from coronary heart disease.


OBJECTIVE
The objective was to compare the short-term effect of a high-fat meal and a high-carbohydrate meal, with and without dietary antioxidants, on vasomotor, antiplatelet, and hemostatic functions of the endothelium in healthy subjects.


METHODS
In an observer-blinded, randomized crossover study, 25 (13 men and 12 women) healthy subjects were given each of 3 meals in random order at 1-wk intervals: a high-fat meal (760 kcal), an isoenergetic high-carbohydrate meal, and a high-fat meal with dietary antioxidants from vegetables (865 kcal). Endothelial functions, as assessed by hemodynamic and rheologic responses to L-arginine--the natural precursor of nitric oxide--were evaluated before and 4 h after each meal.


RESULTS
Unlike the high-carbohydrate meal, the high-fat meal increased the plasma concentrations of triacylglycerol (P < 0.01); both meals activated hemostasis. The high-carbohydrate meal did not modify blood pressure, and platelet aggregation decreased in response to the L-arginine load (-7.1 +/- 2.3 mm Hg and -8.5 +/- 4.5%, respectively). After the high-fat meal, the decrease in blood pressure in response to L-arginine was reduced (-1 +/- 0.8 mm Hg), and platelet aggregation showed a paradoxical increase (4.1 +/- 2.1%; P < 0.01 compared with the high-carbohydrate meal). The high-fat meal with antioxidants partially restored the vascular response to L-arginine.


CONCLUSIONS
Compared with a high-carbohydrate meal, a high-fat meal can modify endothelial functions toward a more atherogenetic profile, which is partially prevented by dietary antioxidants.
Esposito
Katherine
K
Department of Geriatrics and Metabolic Diseases, Second University of Naples, Italy.
Nappo
Francesco
F
Giugliano
Francesco
F
Giugliano
Giovanni
G
Marfella
Raffaele
R
Giugliano
Dario
D
D000328:Adult; D000975:Antioxidants / Q000008:administration & dosage / Q000494:pharmacology*; D001794:Blood Pressure / Q000187:drug effects; D002784:Cholesterol / Q000097:blood; D018592:Cross-Over Studies; D004040:Dietary Carbohydrates / Q000008:administration & dosage / Q000494:pharmacology*; D004041:Dietary Fats / Q000008:administration & dosage / Q000494:pharmacology*; D004730:Endothelium, Vascular / Q000187:drug effects*; D005260:Female; D006801:Humans; D008297:Male; D010974:Platelet Aggregation / Q000187:drug effects; D019518:Postprandial Period
D000975:Antioxidants; D004040:Dietary Carbohydrates; D004041:Dietary Fats; D002784:Cholesterol