title: Serotonin precursor influenced by type of carbohydrate meal in healthy adults.
abstract: We compared the effects on the ratio of plasma tryptophan to large neutral amino acids (trp:LNAA) of two different carbohydrate meals (sucrose or starch, 120 g) and a contrasting meal of fat + protein given at breakfast to 10 healthy adults. Plasma glucose and insulin were also measured. The trp:LNAA ratio rose after both carbohydrate meals (p less than 0.001). Glucose and insulin peaks were higher after sucrose than starch, and trp:LNAA rose correspondingly higher (sucrose +34% and starch +20%, p less than 0.05). The ratio declined 45% after the fat + protein meal. At 180 min, absolute ratio values were twofold higher after carbohydrate (sucrose 0.133 and starch 0.127) than after fat + protein (0.057). Similar results were found with the same meals given in the evening. Our results suggest that high-carbohydrate meals have an influence on serotonin synthesis. We predict that carbohydrates with a high glycemic index would have a greater serotoninergic effect than carbohydrates with a low glycemic index.
authors.affiliation: Department of Biochemistry, University of Sydney, NSW, Australia.
authors.forename: P M
authors.initials: PM
authors.lastname: Lyons
authors.forename: A S
authors.initials: AS
authors.lastname: Truswell
mesh_terms: D000328:Adult; D000596:Amino Acids / Q000097:blood*; D001786:Blood Glucose / Q000378:metabolism; D004040:Dietary Carbohydrates / Q000494:pharmacology*; D004041:Dietary Fats / Q000494:pharmacology; D004044:Dietary Proteins / Q000494:pharmacology; D005260:Female; D005502:Food; D006801:Humans; D007328:Insulin / Q000097:blood; D008297:Male; D012701:Serotonin / Q000096:biosynthesis*; D013213:Starch / Q000494:pharmacology; D013395:Sucrose / Q000494:pharmacology; D014364:Tryptophan / Q000097:blood*
chemical_list: D000596:Amino Acids; D001786:Blood Glucose; D004040:Dietary Carbohydrates; D004041:Dietary Fats; D004044:Dietary Proteins; D007328:Insulin; D012701:Serotonin; D013395:Sucrose; D014364:Tryptophan; D013213:Starch