![[Feedback]](/icons/banner/feedbackACT.gif){kind=icon}
![[For Subscribers]](/icons/banner/subscriberACT.gif){kind=icon}
![[Archive]](/icons/banner/archiveACT.gif){kind=icon}
![[Search]](/icons/banner/searchACT.gif){kind=icon}
![[Contents]](/icons/banner/tocACT.gif){kind=icon}
|
|
|
|
|
||
,,,3
* Department of Nutritional Sciences, University of Toronto, Toronto, Ontario, Canada M5S 3E2;
The Research Institute, The Hospital for Sick Children, Toronto, Ontario, Canada M5G 1X8;
** School of Dietetics and Human Nutrition, McGill University, Ste-Anne-de-Bellevue, Quebec, Canada H9X 3V9;
Department of Agricultural, Food and Nutritional Sciences, University of Alberta, Edmonton, Alberta, Canada T6G 2P5; and
Department of Paediatrics, University of Toronto, Toronto, Ontario, Canada M5G 1X8
3To whom correspondence should be addressed. E-mail: paul.pencharz{at}sickkids.ca
Previous recommendations for branched-chain amino acids (BCAA), based on nitrogen balance studies, were found to be low in a series of stable isotope–labeled amino acid studies. The BCAA requirement was increased in the new dietary reference intake (DRI) report on the basis of a series of stable isotope studies examining the requirement of leucine and valine individually, but not isoleucine. To reduce the possibility of interactions among these amino acids and imbalances in the mixture affecting the estimate of requirements, we decided to determine the requirement for the total BCAA of young healthy adult men, receiving a mixture of BCAA based on the proportion of these amino acids in egg protein, by use of indicator amino acid oxidation. Seven men were assigned to receive nine graded intakes of a BCAA mixture in random order: 34, 50, 66, 80, 100, 120, 140, 160 and 180 mg/(kg · d). The rate of release of 13CO2 from the oxidation of L-[1-13C]phenylalanine (F 13CO2) was measured and a two-phase linear regression crossover model was applied to determine total BCAA requirement. The mean requirement and population-safe level (upper limit of 95% confidence interval) of the total BCAA were 144 and 210 mg/(kg · d), respectively. Based on the balance of BCAA in egg protein, our estimate for the mean leucine requirement is 55 mg/(kg · d), which is substantially higher than the 34 mg/(kg · d) recommended by the DRI.
KEY WORDS: • amino acid requirements • branched-chain amino acids • indicator amino acid oxidation
This article has been cited by other articles:
|
|
 |
|
  M. A Humayun, R. Elango, R. O Ball, and P. B Pencharz Reevaluation of the protein requirement in young men with the indicator amino acid oxidation technique Am. J. Clinical Nutrition, October 1, 2007; 86(4): 995 - 1002. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
R. Elango, M. A Humayun, R. O Ball, and P. B Pencharz Lysine requirement of healthy school-age children determined by the indicator amino acid oxidation method Am. J. Clinical Nutrition, August 1, 2007; 86(2): 360 - 365. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 M. A. Humayun, R. Elango, S. Moehn, R. O. Ball, and P. B. Pencharz Application of the Indicator Amino Acid Oxidation Technique for the Determination of Metabolic Availability of Sulfur Amino Acids from Casein versus Soy Protein Isolate in Adult Men J. Nutr., August 1, 2007; 137(8): 1874 - 1879. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
M. A Humayun, J. M Turner, R. Elango, M. Rafii, V. Langos, R. O Ball, and P. B Pencharz Minimum methionine requirement and cysteine sparing of methionine in healthy school-age children. Am. J. Clinical Nutrition, November 1, 2006; 84(5): 1080 - 1085. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
J. W-C. Hsu, W. Kriengsinyos, L. J. Wykes, M. Rafii, L. A. Goonewardene, R. O. Ball, and P. B. Pencharz Leucine Is Not a Good Choice as an Indicator Amino Acid for Determining Amino Acid Requirements in Men J. Nutr., April 1, 2006; 136(4): 958 - 964. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
D. R. Mager, L. J. Wykes, E. A. Roberts, R. O. Ball, and P. B. Pencharz Mild-to-Moderate Chronic Cholestatic Liver Disease Increases Leucine Oxidation in Children J. Nutr., April 1, 2006; 136(4): 965 - 970. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
J. M Turner, M. A Humayun, R. Elango, M. Rafii, V. Langos, R. O Ball, and P. B Pencharz Total sulfur amino acid requirement of healthy school-age children as determined by indicator amino acid oxidation technique Am. J. Clinical Nutrition, March 1, 2006; 83(3): 619 - 623. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
Y. Shimomura, Y. Yamamoto, G. Bajotto, J. Sato, T. Murakami, N. Shimomura, H. Kobayashi, and K. Mawatari Nutraceutical Effects of Branched-Chain Amino Acids on Skeletal Muscle J. Nutr., February 1, 2006; 136(2): 529S - 532S. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
D. R. Mager, L. J. Wykes, E. A. Roberts, R. O. Ball, and P. B. Pencharz Branched-Chain Amino Acid Needs in Children with Mild-to-Moderate Chronic Cholestatic Liver Disease J. Nutr., January 1, 2006; 136(1): 133 - 139. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
A. V. Kurpad, M. M. Regan, T. Raj, and J. V. Gnanou Branched-Chain Amino Acid Requirements in Healthy Adult Human Subjects J. Nutr., January 1, 2006; 136(1): 256S - 263S. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 D. H. Baker Inaugural Article: Comparative nutrition and metabolism: Explication of open questions with emphasis on protein and amino acids PNAS, December 13, 2005; 102(50): 17897 - 17902. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
A. V Kurpad, M. M Regan, T. D. Raj, J. V Gnanou, V. N Rao, and V. R Young The daily valine requirement of healthy adult Indians determined by the 24-h indicator amino acid balance approach Am. J. Clinical Nutrition, August 1, 2005; 82(2): 373 - 379. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
D. H. Baker Tolerance for Branched-Chain Amino Acids in Experimental Animals and Humans J. Nutr., June 1, 2005; 135(6): 1585S - 1590S. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 R. Riazi, M. Rafii, J. T. R. Clarke, L. J. Wykes, R. O. Ball, and P. B. Pencharz Total branched-chain amino acids requirement in patients with maple syrup urine disease by use of indicator amino acid oxidation with L-[1-13C]phenylalanine Am J Physiol Endocrinol Metab, July 1, 2004; 287(1): E142 - E149. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
P. B. Pencharz and R. O. Ball Amino Acid Needs for Early Growth and Development J. Nutr., June 1, 2004; 134(6): 1566S - 1568S. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
R. Riazi, M. Rafii, L. J. Wykes, R. O. Ball, and P. B. Pencharz Valine May Be the First Limiting Branched-Chain Amino Acid in Egg Protein in Men J. Nutr., November 1, 2003; 133(11): 3533 - 3539. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
D. R. Mager, L. J. Wykes, R. O. Ball, and P. B. Pencharz Branched-Chain Amino Acid Requirements in School-Aged Children Determined by Indicator Amino Acid Oxidation (IAAO) J. Nutr., November 1, 2003; 133(11): 3540 - 3545. [Abstract] [Full Text] [PDF]
|
|
