학술논문
Fluctuations in dietary methionine intake do not alter plasma homocysteine concentration in healthy men.
Document Type
Journal Article
Author
Source
Subject
*METHIONINE
*HOMOCYSTEINE
*PHYSIOLOGY of men
*PHYSIOLOGY
*CLINICAL trials
*COMPARATIVE studies
*DIET
*INGESTION
*RESEARCH methodology
*MEDICAL cooperation
*QUESTIONNAIRES
*RESEARCH
*VITAMIN B12
*EVALUATION research
*BODY mass index
*RANDOMIZED controlled trials
*FOOD diaries
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*
Language
ISSN
0022-3166
Abstract
A moderate elevation in plasma total homocysteine (tHcy) has been established as an independent risk factor for vascular disease. An important exogenous source of homocysteine is methionine found in foods rich in animal protein. We investigated the response of tHcy to fluctuations in methionine intake in a cross-over intervention trial (two arms). Healthy men (n = 52; 19-29 y) were screened for habitual methionine intake using a food-frequency questionnaire. Subjects in the top quartile for methionine intake (n = 13), with a baseline fasting tHcy of 7.01 +/- 1.84 micromol/L (mean +/- SD), were randomly assigned to receive either a low-methionine intervention diet for 1 wk followed by a control diet for 1 wk or vice-versa. Simultaneously, those in the bottom quartile for methionine intake (n = 11), with a fasting plasma tHcy of 9.79 +/- 7. 20 micromol/L (mean +/- SD), received either a high methionine intervention diet for 1 wk followed by a control diet or vice-versa. All subjects had serum folate, red-cell folate, serum vitamin B-12 and plasma pyridoxal phosphate (PLP) concentrations within normal ranges. During the intervention, subjects in the top quartile for methionine intake reduced their daily methionine intake 79%, from 1969 +/- 639 to 407 +/- 83 mg/d (P: = 0.001), and those in the bottom quartile almost doubled their methionine intake, from 1155 +/- 401 to 2112 +/- 379 mg/d (P: = 0.001). Despite these changes in methionine intake, no corresponding changes in plasma tHcy were observed. These results suggest that in the absence of an obvious deficiency of relevant B-vitamins, fasting plasma tHcy is unaffected by intermediate-term fluctuations (up to 100% of usual intake) in dietary methionine. [ABSTRACT FROM AUTHOR]