Print Email Facebook Twitter Dietary serine and cystine attenuate the homocysteine-raising effect of dietary methionine: A randomized crossover trial in humans Title Dietary serine and cystine attenuate the homocysteine-raising effect of dietary methionine: A randomized crossover trial in humans Author Verhoef, P. Steenge, G.R. Boelsma, E. van Vliet, T. Olthof, M.R. Katan, M.B. TNO Voeding Publication year 2004 Abstract Background: A high plasma total homocysteine (tHcy) concentration is a risk factor for cardiovascular disease. The increase in tHcy induced by methionine, the sole dietary precursor of homocysteine, might be modulated by other amino acids present in dietary proteins. Objectives: Our objectives were to compare the postprandial effect of free and dietary methionine on plasma tHcy concentrations and to investigate whether serine and cystine modify the effect of free methionine on tHcy. Design: We conducted a randomized crossover trial in 24 healthy men. Each subject ingested 4 meals on separate days, which were separated by 1 wk. tHcy concentrations were measured in the fasting state and at 2, 4, 6, 8, 10, and 24 h after meal ingestion. The meals were 1) a low-protein meal fortified with 30 mg methionine/kg body wt (reference, denoted by "Met"), 2) meal 1 additionally fortified with 60.6 mg serine/kg body wt (MetSer), 3) meal 1 additionally fortified with 12.3 mg cystine/kg body wt (MetCys), and 4) a protein-rich meal containing 30 mg methionine, 60.6 mg serine, and 12.3 mg cystine per kg body wt (Protein). Results: The mean (±SD) fasting tHcy concentration was 9.1 ± 2.7 μmol/L. Mean peak tHcy concentrations were 17.9 ± 4.5, 14.3 ± 3.3, 14.8 ± 3.9, and 11.2 ± 3.1 μmol/L after Met, MetSer, MetCys, and Protein, respectively. Compared with the mean 24-h area under the tHcy-by-time curve after Met, the mean curves after MetSer, MetCys, and Protein were 37%, 32%, and 77% smaller, respectively (all P < 0.0005). Conclusions: Dietary methionine increases tHcy much less than does free methionine. Serine and cystine attenuate the tHcy-raising effect of free methionine. Thus, dietary proteins with a high content of serine or cystine relative to methionine may lead to lower postprandial tHcy responses. © 2004 American Society for Clinical Nutrition. Subject NutritionPhysiological SciencesCrossover studyCysteineDietary proteinHomocysteineMethionineSerinecysteinehomocysteinemethionineserinecystineamino acid blood levelarea under the curvearticleattenuationbody weightclinical trialconcentration (parameters)controlled clinical trialcontrolled studydietary intakefood intakehumanmalemealmeasurementnormal humanpostprandial stateprotein restrictionrandomized controlled trialadultanalysis of variancebloodcardiovascular diseasecrossover procedurediet restrictiondrug effectmetabolismprotein intakeAdultAnalysis of VarianceArea Under CurveCardiovascular DiseasesCross-Over StudiesCystineDietary ProteinsFastingHomocysteineHumansMaleMethionineSerine To reference this document use: http://resolver.tudelft.nl/uuid:8b976af3-4b23-47d0-95d8-76c70d8c8f6a TNO identifier 237986 ISSN 0002-9165 Source American Journal of Clinical Nutrition, 80 (3), 674-679 Document type article Files To receive the publication files, please send an e-mail request to TNO Library.