Glycemia and insulinemia in healthy subjects after lactose-equivalent meals of milk and other food proteins: the role of plasma amino acids and incretins

• Published in: The American journal of clinical nutrition Vol. 80; no. 5; pp. 1246 - 1253
• Main Authors: Nilsson, M, Stenberg, M, Frid, A.H, Holst, J.J, Bjorck, I.M.E
• Format: Journal Article
• Language: English
• Published: Bethesda, MD American Society for Clinical Nutrition 01.11.2004; American Society for Clinical Nutrition, Inc
• Subjects: administration & dosage; Adult; Amino Acids; Amino Acids - blood; Area Under Curve; Biological and medical sciences; blood; blood glucose; Blood Glucose - drug effects; breads; Carbohydrates; cheeses; cod (fish); Diet; dried milk; drug effects; Feeding. Feeding behavior; Female; food serving methods; Fundamental and applied biological sciences. Psychology; glucagon-like peptides; Glucose; Glycemic Index; Hormones; Humans; hyperinsulinemia; Insulin; Insulin - blood; lactose; lysine; Male; Meals; Milk; milk proteins; Milk Proteins - administration & dosage; Milk Proteins - pharmacokinetics; Milk Proteins - pharmacology; Nutrition; Peptides; pharmacokinetics; pharmacology; Plasma; Postprandial Period; Proteins; reconstituted milk; valine; Vertebrates: anatomy and physiology, studies on body, several organs or systems; wheat gluten; whey; whey powder; Human; insulin index; Pancreatic hormone; Healthy subject; Meal; amino acids; Glycemic index; Index; Whey; Insulin; Blood plasma; insulinotropic amino acids; Lactose; Milk protein; Aminoacid; food proteins; incretin hormones; Glycemia; Food; Milk
• ISSN: 0002-9165; 1938-3207
• DOI: 10.1093/ajcn/80.5.1246

Background: Milk products deviate from other carbohydrate-containing foods in that they produce high insulin responses, despite their low GI. The insulinotropic mechanism of milk has not been elucidated. Objective: The objective was to evaluate the effect of common dietary sources of animal or vegetable proteins on concentrations of postprandial blood glucose, insulin, amino acids, and incretin hormones glucose-dependent insulinotropic polypeptide (GIP) and glucagon-like peptide 1 in healthy subjects. Design: Twelve healthy volunteers were served test meals consisting of reconstituted milk, cheese, whey, cod, and wheat gluten with equivalent amounts of lactose. An equicarbohydrate load of white-wheat bread was used as a reference meal. Results: A correlation was found between postprandial insulin responses and early increments in plasma amino acids; the strongest correlations were seen for leucine, valine, lysine, and isoleucine. A correlation was also obtained between responses of insulin and GIP concentrations. Reconstituted milk powder and whey had substantially lower postprandial glucose areas under the curve (AUCs) than did the bread reference (-62% and -57%, respectively). Whey meal was accompanied by higher AUCs for insulin (90%) and GIP (54%). Conclusions: It can be concluded that food proteins differ in their capacity to stimulate insulin release, possibly by differently affecting the early release of incretin hormones and insulinotropic amino acids. Milk proteins have insulinotropic properties; the whey fraction contains the predominating insulin secretagogue.