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Rafii M, Paoletti A, He H, Porto B, Szwiega S, Pencharz PB, Ball RO, Kong D, Xu L, Elango R, Courtney-Martin G. Dietary lysine requirements of older adults stratified by age and sex. J Nutr 2024:S0022-3166(24)00237-2. [PMID: 38735574 DOI: 10.1016/j.tjnut.2024.04.034] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2024] [Revised: 04/17/2024] [Accepted: 04/26/2024] [Indexed: 05/14/2024] Open
Abstract
BACKGROUND Current recommendation for lysine in older adults, 30 mg. kg-1.d-1, is based on young adult data. Evidence suggests that amino acid requirements may differ between young and old adults with both sex and age having an effect in the elderly OBJECTIVES: 1) Define the lysine requirements in healthy older adults using the indicator amino acid oxidation (IAAO) method with L-[1-13C]phenylalanine as the indicator and 2) compare the derived estimates based on age: 60-69y and >70y METHODS: Fourteen healthy males and 16 healthy females (> 60y, BMI=26.3 kg.m-2) were randomly assigned to receive 3 to 7 lysine intakes from 10 to 80 mg. kg-1. d-1. Subjects were adapted to a standard liquid diet providing 1.0 g. kg-1.d-1 protein and adequate energy, for 2 days, with indicator oxidation measurements performed on day three. The rate of release of 13CO2 from the oxidation of L-[1-13C] phenylalanine was measured in breath. A two-phase linear mixed effect model, and parametric bootstrap were used to determine mean lysine requirements and the 95% confidence intervals (CI). The overlap of the 95% CI between the 2 age groups were used to compare the requirement estimates. The null hypothesis was accepted if the interval contained zero RESULTS: The mean and upper 95% CI of the lysine requirement for females were 32.9 and 40.9, and 46.2 and 53.7 mg. kg-1.d-1 for those 60-69 and >70y, respectively. The mean and upper 95% CI of the lysine requirement for the 2 groups of males were not different, so was combined to yield a mean and 95% CI of 32.2 and 38.2 mg. kg-1.d-1 CONCLUSIONS: This is the first study to report on the lysine requirement in older adults >60y. These results provide a basis from which the adequacy of diets to meet lysine needs of older adults can be assessed. THE TRIAL WAS REGISTERED AT CLINICAL TRIALS REGISTRY: # NCT02008955, https://clinicaltrials.gov/study/NCT02008955.
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Affiliation(s)
- Mahroukh Rafii
- Research Institute, Hospital for Sick Children, Toronto, Ontario, Canada M5G 1X8
| | - Alyssa Paoletti
- Research Institute, Hospital for Sick Children, Toronto, Ontario, Canada M5G 1X8
| | - Henry He
- Research Institute, Hospital for Sick Children, Toronto, Ontario, Canada M5G 1X8
| | - Beatriz Porto
- Research Institute, Hospital for Sick Children, Toronto, Ontario, Canada M5G 1X8
| | - Sylwia Szwiega
- Research Institute, Hospital for Sick Children, Toronto, Ontario, Canada M5G 1X8
| | - Paul B Pencharz
- Research Institute, Hospital for Sick Children, Toronto, Ontario, Canada M5G 1X8; Departments of Nutritional Sciences; Paediatrics, University of Toronto, Toronto, Ontario, Canada M5S 2Z9
| | - Ronald O Ball
- Department of Agriculture, Food and Nutritional Science, University of Alberta, Edmonton, Alberta, Canada, T6G 2P5
| | | | - Libai Xu
- School of Mathematical Sciences, Soochow University, Suzhou,Jiangsu, China, 215006
| | - Rajavel Elango
- Department of Pediatrics, School of Population and Public Health, University of British Columbia, Vancouver, BC, Canada;; BC Children's Hospital Research Institute, BC Children's Hospital, Vancouver, BC, Canada, V5Z 4H4
| | - Glenda Courtney-Martin
- Research Institute, Hospital for Sick Children, Toronto, Ontario, Canada M5G 1X8; Departments of Nutritional Sciences.
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Paoletti A, Pencharz PB, Ball RO, Kong D, Xu L, Elango R, Courtney-Martin G. Corrigendum to "The dietary requirement for total sulfur amino acids in adults aged >60 years appears to be higher in males than in females" [Am J Clin Nutr 118(3) 2023 538-548]. Am J Clin Nutr 2023; 118:1243. [PMID: 37844874 DOI: 10.1016/j.ajcnut.2023.10.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2023] Open
Affiliation(s)
- Alyssa Paoletti
- Research Institute, Hospital for Sick Children, Toronto, Ontario, Canada
| | - Paul B Pencharz
- Research Institute, Hospital for Sick Children, Toronto, Ontario, Canada; Department of Nutritional Sciences, University of Toronto, Toronto, Ontario, Canada; Department of Paediatrics, University of Toronto, Toronto, Ontario, Canada
| | - Ronald O Ball
- Department of Agriculture, Food, and Nutritional Science, University of Alberta, Edmonton, Alberta, Canada
| | - Dehan Kong
- Department of Statistical Sciences, University of Toronto, Toronto, Ontario, Canada
| | - Libai Xu
- Department of Statistical Sciences, University of Toronto, Toronto, Ontario, Canada
| | - Rajavel Elango
- Department of Pediatrics, School of Population and Public Health, University of British Columbia, Vancouver, BC, Canada; BC Children's Hospital Research Institute, BC Children's Hospital, Vancouver, BC, Canada
| | - Glenda Courtney-Martin
- Research Institute, Hospital for Sick Children, Toronto, Ontario, Canada; Department of Nutritional Sciences, University of Toronto, Toronto, Ontario, Canada.
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Paoletti A, Pencharz PB, Ball RO, Kong D, Xu L, Elango R, Courtney-Martin G. The Minimum Methionine Requirement for Adults Aged ≥60 Years Is the Same in Males and Females. Nutrients 2023; 15:4112. [PMID: 37836396 PMCID: PMC10574673 DOI: 10.3390/nu15194112] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2023] [Revised: 09/18/2023] [Accepted: 09/21/2023] [Indexed: 10/15/2023] Open
Abstract
The minimum methionine requirement in the presence of excess dietary cysteine has not been determined in older adults. This study aimed to determine the minimum methionine requirement in healthy older adults using the indicator amino acid oxidation (IAAO) method. Fifteen healthy adults ≥ 60 years of age received seven methionine intakes (0 to 20 mg/kg/d) plus excess dietary cysteine (40 mg/kg/d). Oxidation of the indicator, L-[1-13C]phenylalanine (F13CO2), was used to estimate the mean minimum methionine requirement using a change-point mixed-effect model. There was no statistical difference between male and female requirement estimates, so the data were pooled to generate a mean of 5.1 mg/kg/d (Rm2 = 0.46, Rc2 = 0.77; p < 0.01; 95% CI: 3.67, 6.53 mg/kg/d). This is the first study to estimate the minimum methionine requirement in healthy older adults, which is the same between the sexes and as our lab's previous estimate in young adults. The findings are relevant considering current recommendations for increased consumption of plant foods, which will help to establish the appropriate balance of methionine and cysteine intake required to satisfy the sulphur amino acid requirements of older adults.
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Affiliation(s)
- Alyssa Paoletti
- Research Institute, Hospital for Sick Children, Toronto, ON M5G 1X8, Canada; (A.P.); (P.B.P.)
- Department of Nutritional Sciences, University of Toronto, Toronto, ON M5S 1A8, Canada
| | - Paul B. Pencharz
- Research Institute, Hospital for Sick Children, Toronto, ON M5G 1X8, Canada; (A.P.); (P.B.P.)
- Department of Nutritional Sciences, University of Toronto, Toronto, ON M5S 1A8, Canada
- Department of Pediatrics, University of Toronto, Toronto, ON M5S 1X8, Canada
| | - Ronald O. Ball
- Department of Agriculture, Food and Nutritional Science, University of Alberta, Edmonton, AB T6G 2P5, Canada;
| | - Dehan Kong
- Department of Statistical Sciences, University of Toronto, Toronto, ON M5S 1X6, Canada;
| | - Libai Xu
- School of Mathematical Sciences, Soochow University, Suzhou 215006, China;
| | - Rajavel Elango
- Department of Pediatrics, School of Population and Public Health, University of British Columbia, Vancouver, BC V6H 0B3, Canada;
- British Columbia Children’s Hospital Research Institute, British Columbia Children’s Hospital, Vancouver, BC V6H 3N1, Canada
| | - Glenda Courtney-Martin
- Research Institute, Hospital for Sick Children, Toronto, ON M5G 1X8, Canada; (A.P.); (P.B.P.)
- Department of Nutritional Sciences, University of Toronto, Toronto, ON M5S 1A8, Canada
- Faculty of Kinesiology and Physical Education, University of Toronto, Toronto, ON M5S 3J7, Canada
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Paoletti A, Pencharz PB, Ball RO, Kong D, Xu L, Elango R, Courtney-Martin G. The dietary requirement for total sulfur amino acids in adults aged ≥60 years appears to be higher in males than in females. Am J Clin Nutr 2023; 118:538-548. [PMID: 37356549 DOI: 10.1016/j.ajcnut.2023.06.015] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2022] [Revised: 05/09/2023] [Accepted: 06/22/2023] [Indexed: 06/27/2023] Open
Abstract
BACKGROUND The total sulfur amino acid (TSAA) recommendation in older adults is based on data from young adults. Physiological evidence suggests that older adults have a higher requirement than young adults. OBJECTIVES The objective of this study was to determine the TSAA requirement in healthy men and women aged ≥60 y. METHODS The TSAA requirement was determined using the indicator amino acid oxidation method with L-[1-13C]phenylalanine as the indicator. At recruitment, 15 older adults (n = 7 men and n = 8 women; BMI < 30 kg/m2) were assigned to receive 7 methionine intakes (5, 10, 15, 19, 25, 35, and 40 mg/kg/d) without dietary cysteine. Intake levels were randomly assigned to each subject. Following enrollment, 2 subjects completed 2 intakes and 3 completed 3, while the remainder completed all 7. Mean TSAA requirement was determined from oxidation of L-[1-13C]phenylalanine using a mixed-effect change-point model. The 95% CI was calculated using parametric bootstrap. To test whether breakpoints were different between men and women, the overlap in the 95% CI was calculated. RESULTS The mean TSAA requirement was 26.2 (Rm2 = 0.39, Rc2 = 0.89; P < 0.001) and 17.1 mg/kg/d (Rm2 = 0.22, Rc2 = 0.79; P < 0.001) for men and women, respectively. The requirement was significantly higher in men than in women (difference in CI: 9.1 ± 8.85). CONCLUSIONS To our knowledge, this is the first study to determine the TSAA requirement in older adults. The requirement in older women is similar to current recommendations but is 75% higher in older men. These findings are important given recommendations for increased plant protein consumption. They will help in the assessment of diet quality and provide the basis of dietary guidelines for older adults consuming a plant-based diet. This trial was registered at clinicaltrials.gov as NCT04595188.
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Affiliation(s)
- Alyssa Paoletti
- Research Institute, Hospital for Sick Children, Toronto, Ontario, Canada
| | - Paul B Pencharz
- Research Institute, Hospital for Sick Children, Toronto, Ontario, Canada; Department of Nutritional Sciences, University of Toronto, Toronto, Ontario, Canada; Department of Paediatrics, University of Toronto, Toronto, Ontario, Canada
| | - Ronald O Ball
- Department of Agriculture, Food, and Nutritional Science, University of Alberta, Edmonton, Alberta, Canada
| | - Dehan Kong
- Department of Statistical Sciences, University of Toronto, Toronto, Ontario, Canada
| | - Libai Xu
- Department of Statistical Sciences, University of Toronto, Toronto, Ontario, Canada
| | - Rajavel Elango
- Department of Pediatrics, School of Population and Public Health, University of British Columbia, Vancouver, British Columbia, Canada; BC Children's Hospital Research Institute, BC Children's Hospital, Vancouver, British Columbia, Canada
| | - Glenda Courtney-Martin
- Research Institute, Hospital for Sick Children, Toronto, Ontario, Canada; Department of Nutritional Sciences, University of Toronto, Toronto, Ontario, Canada.
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Szwiega S, Pencharz PB, Ball RO, Xu L, Kong D, Elango R, Courtney-Martin G. Length of Adaptation Has No Effect on the Threonine Requirement Determined in Healthy Young Adult Males Using the Indicator Amino Acid Oxidation Method. J Nutr 2023; 153:2016-2026. [PMID: 37004875 DOI: 10.1016/j.tjnut.2023.03.033] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2022] [Revised: 03/21/2023] [Accepted: 03/28/2023] [Indexed: 04/03/2023] Open
Abstract
BACKGROUND The indicator amino acid oxidation (IAAO) method is minimally invasive; therefore, it is applicable to study the amino acid (AA) requirements of individuals in various age groups. However, the accuracy of this method has been criticized because of the 8 h (1 d) protocol, which has been suggested to be too short an adaptation time for estimating AA requirements. OBJECTIVES The IAAO method was used to determine whether 3 or 7 d of adaptation to each threonine intake alters the threonine requirement in adult men compared to 1 d of adaptation. METHODS Eleven healthy adult men (19-35 y, body mass index (BMI) 23.4 in kg⋅m-2) were studied at 6 threonine intakes; each intake was studied over a 9 d period. Following 2 d of pre-adaptation to adequate protein intake (1.0 g·kg-1⋅d-1), subjects received experimental diets containing the randomly assigned test threonine intake (5, 10, 15, 20, 25, or 35 mg·kg-1·d-1) for 7 d. IAAO studies were performed on days 1, 3, and 7 of adaptation to the experimental diet. The rate of release of 13CO2 from the oxidation of L-[1-13C]phenylalanine (F13CO2) was measured, and the threonine requirement was determined by applying mixed-effect change-point regression to the F13CO2 data in R version 4.0.5. The 95% confidence interval (CI) was calculated using parametric bootstrap, and the requirement estimates on days 1, 3, and 7 were compared using analysis of variance (ANOVA). RESULTS The mean threonine requirements (upper, lower 95% CI) for days 1, 3, and 7 were 10.5 (5.7, 15.9), 10.6 (7.5, 13.7), and 12.1 (9.2, 15.0 mg·kg-1·d-1), respectively; and these requirements were not statistically different (P = 0.213). CONCLUSIONS We demonstrated that the short, 8 h IAAO protocol results in a threonine requirement that is not statistically different from that obtained on days 3 or 7 of adaptation in healthy adult males. This trial was registered at www. CLINICALTRIALS gov as NCT04585087.
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Affiliation(s)
- Sylwia Szwiega
- Research Institute, Hospital for Sick Children, Toronto, Ontario, Canada
| | - Paul B Pencharz
- Research Institute, Hospital for Sick Children, Toronto, Ontario, Canada; Departments of Nutritional Sciences, University of Toronto, Toronto, Ontario, Canada; Department of Paediatrics, University of Toronto, Toronto, Ontario, Canada
| | - Ronald O Ball
- Department of Agriculture, Food and Nutritional Science, University of Alberta, Edmonton, Alberta, Canada
| | - Libai Xu
- Department of Statistical Sciences, University of Toronto, Toronto, Ontario, Canada
| | - Dehan Kong
- Department of Statistical Sciences, University of Toronto, Toronto, Ontario, Canada
| | - Rajavel Elango
- Department of Pediatrics, School of Population and Public Health, University of British Columbia, Vancouver, British Columbia, Canada; British Columbia Children's Hospital Research Institute, British Columbia Children's Hospital, Vancouver, British Columbia, Canada
| | - Glenda Courtney-Martin
- Research Institute, Hospital for Sick Children, Toronto, Ontario, Canada; Departments of Nutritional Sciences, University of Toronto, Toronto, Ontario, Canada; Faculty of Kinesiology and Physical Education, University of Toronto, Toronto, Ontario, Canada.
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Shoveller AK, Pezzali JG, House JD, Bertolo RF, Pencharz PB, Ball RO. Methionine and cysteine oxidation are regulated in a dose dependent manner by dietary Cys intake in neonatal piglets receiving enteral nutrition. PLoS One 2022; 17:e0275760. [PMID: 36301815 PMCID: PMC9612549 DOI: 10.1371/journal.pone.0275760] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2022] [Accepted: 09/22/2022] [Indexed: 11/18/2022] Open
Abstract
Methionine (Met) is an indispensable amino acid (AA) in piglets. Met can synthesize cysteine (Cys), and Cys has the ability to reduce the Met requirement by 40% in piglets. However, whether this sparing effect on Met is facilitated by downregulation of Cys synthesis has not been shown. This study investigated the effects of graded levels of Cys on Met and Cys oxidation, and on plasma AA concentrations. Piglets (n = 32) received a complete elemental diet via gastric catheters prior to being randomly assigned to one of the eight dietary Cys levels (0, 0.05, 0.1, 0.15, 0.2, 0.25, 0.40, 0.50 g kg-1d-1) with an adequate Met concentration (0.25g kg-1d-1). Constant infusion of L-[1-14C]-Met and L-[1-14C]-Cys were performed for 6 h on d 6 and d 8 to determine Met and Cys oxidation, respectively. Met oxidation decreased as Cys intake increased (P<0.05). At higher Cys intakes (0.15 to 0.5g kg-1d-1), Met oxidation decreased (P<0.05) at a slower rate. Cys oxidation was similar (P>0.05) among dietary Cys intakes; however, a significant polynomial relationship was observed between Cys oxidation and intake (P<0.05, R2 = 0.12). Plasma Met concentrations increased (P<0.05) linearly with increasing levels of dietary Cys, while plasma Cys concentrations changed (P<0.05) in a cubic manner and the highest concentrations occurred at the highest intake levels. Increasing dietary levels of Cys resulted in a reduction in Met oxidation until the requirement for the total sulfur AA was met, indicating the sparing capacity by Cys of Met occurs through inhibition of the transsulfuration pathway in neonatal piglets.
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Affiliation(s)
- Anna K. Shoveller
- Department of Agricultural, Food and Nutritional Science, University of Alberta, Edmonton, Alberta, Canada
- * E-mail:
| | - Julia G. Pezzali
- Department of Animal Biosciences, University of Guelph, Guelph, Ontario, Canada
| | - James D. House
- Department of Food and Human Nutritional Sciences, University of Manitoba, Winnipeg, Manitoba, Canada
| | - Robert F. Bertolo
- Department of Biochemistry, Memorial University of Newfoundland, St. John’s, Newfoundland, Canada
| | - Paul B. Pencharz
- Department of Agricultural, Food and Nutritional Science, University of Alberta, Edmonton, Alberta, Canada
- The Research Institute, The Hospital for Sick Children, Toronto, Canada
- Department of Paediatrics, University of Toronto, Toronto, Ontario, Canada
| | - Ronald O. Ball
- Department of Agricultural, Food and Nutritional Science, University of Alberta, Edmonton, Alberta, Canada
- The Research Institute, The Hospital for Sick Children, Toronto, Canada
- Department of Nutritional Sciences, University of Toronto, Toronto, Ontario, Canada
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Rafii M, Pencharz PB, Boileau K, Ball RO, Tomlinson C, Elango R, Courtney-Martin G. Metabolic Availability of Methionine Assessed Using Indicator Amino Acid Oxidation Method, Is Greater when Cooked Lentils and Steamed Rice Are Combined in the Diet of Healthy Young Men. J Nutr 2022; 152:1467-1475. [PMID: 35218191 DOI: 10.1093/jn/nxac049] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2021] [Revised: 07/20/2021] [Accepted: 02/22/2022] [Indexed: 11/14/2022] Open
Abstract
BACKGROUND Lentil is considered a high protein source. However, it is low in sulphur amino acids (SAA) and their metabolic availability (MA) is further affected by antinutritional factors in lentils. The combination of lentils with grains such as rice can enhance the protein quality of a lentil-based meal but the MA of SAA in lentils must first be known. OBJECTIVES The objectives of the current study were to assess the MA of methionine in lentils and to test the effects of consumption of complementing lentils with rice in young adults. METHODS Five healthy young men [age <30 y, BMI <25 (in kg/m2)] were each studied at 8 or 10 intake amounts of methionine in random order; 4 daily intake amounts of l-methionine: 0.5, 1, 2, and 3 mg.kg-1.d-1 (reference diet), 3 daily intake amounts of methionine from lentils, and 3 daily intake amounts of the mixed meal of lentils + rice (test diets). The MA of methionine and the effects of complementation were assessed by comparing the indicator amino acid oxidation (IAAO) response to varying intakes of methionine in cooked Canadian lentils, and in rice + lentils combined, compared with the IAAO response to l-methionine intakes in the reference protein (crystalline AA mixture patterned after egg protein) using the slope ratio method. l-[1-13C] phenylalanine was used as the indicator. Data were analyzed using the procedure "MIXED" with subject as a random variable, and oxidation day as repeated measure. RESULTS The MA of methionine from lentils was 69%. Complementation of cooked lentils with rice decreased the oxidation of l-[1-13C] phenylalanine by up to 16% (P < 0.05). CONCLUSIONS The content and MA of methionine are low in lentils. However, combination of lentils with rice in a 1:1 ratio can improve the protein quality of lentil-based diets, resulting in increased protein synthesis in young healthy adults. This trial was registered at www.clinical trials.gov as NCT03110913.
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Affiliation(s)
- Mahroukh Rafii
- Research Institute, Hospital for Sick Children, Toronto, Ontario, Canada
| | - Paul B Pencharz
- Research Institute, Hospital for Sick Children, Toronto, Ontario, Canada.,Departments of Nutritional Sciences, University of Toronto, Toronto, Ontario, Canada.,Departments of Paediatrics, University of Toronto, Toronto, Ontario, Canada
| | - Kaylem Boileau
- Research Institute, Hospital for Sick Children, Toronto, Ontario, Canada
| | - Ronald O Ball
- Departments of Nutritional Sciences, University of Toronto, Toronto, Ontario, Canada.,Department of Agriculture, Food and Nutritional Science, University of Alberta, Edmonton, Alberta, Canada
| | - Christopher Tomlinson
- Research Institute, Hospital for Sick Children, Toronto, Ontario, Canada.,Departments of Nutritional Sciences, University of Toronto, Toronto, Ontario, Canada.,Departments of Paediatrics, University of Toronto, Toronto, Ontario, Canada
| | - Rajavel Elango
- Department of Pediatrics, School of Population and Public Health, University of British Columbia, Vancouver, BC, Canada.,BC Children's Hospital Research Institute, BC Children's Hospital, Vancouver, BC, Canada
| | - Glenda Courtney-Martin
- Research Institute, Hospital for Sick Children, Toronto, Ontario, Canada.,Departments of Nutritional Sciences, University of Toronto, Toronto, Ontario, Canada.,Faculty of Kinesiology & Physical Education, University of Toronto, Toronto, Ontario, Canada
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Paoletti A, Fakiha A, Tul-Noor Z, Pencharz PB, Levesque CL, Ball RO, Kong D, Elango R, Courtney-Martin G. Bioavailable Lysine Assessed Using the Indicator Amino Acid Oxidation Method in Healthy Young Males is High when Sorghum is Cooked by a Moist Cooking Method. J Nutr 2021; 152:770-778. [PMID: 34871427 PMCID: PMC8891180 DOI: 10.1093/jn/nxab410] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2021] [Revised: 06/04/2021] [Accepted: 12/01/2021] [Indexed: 11/15/2022] Open
Abstract
BACKGROUND Sorghum is the fifth most consumed cereal grain but limiting in the indispensable amino acid lysine. Complementing sorghum with lentils can improve the quality of sorghum-based diets. However, knowledge of lysine bioavailability in sorghum is lacking. OBJECTIVES The study objectives were to determine the bioavailability of lysine in sorghum and to assess the effect of complementation of sorghum and lentils in a mixed-meal format. METHODS We studied 5 healthy young men (≤30 years; BMI <25 kg/m2) in a repeated-measure design using the indicator amino acid oxidation (IAAO) method, with L-[1-13C] phenylalanine as the indicator. Each subject participated in 8 determinations in random order. On the reference diet, subjects received 4 amounts of L-lysine (5, 8, 12, and 15 mg. kg-1 . d-1) from a crystalline amino acid mixture patterned after egg protein. On the test diet, they received 3 levels of lysine (8.2, 12.5, and 15.7 mg. kg-1 . d-1) from sorghum, and on the complementation diet they received 1 level of lysine from a mixed meal of sorghum and lentils. The bioavailability of lysine in sorghum was estimated by comparing the IAAO response to the test diet with the IAAO response to the reference diet using the slope-ratio method. Effectiveness of complementation was assessed by comparing the IAAO response to the mixed meal to the IAAO response to the test protein. RESULTS The bioavailability of lysine from sorghum was 94%. Upon complementation with lentils, there was a decline in the oxidation of L-[1-13C] phenylalanine by 19% (P < 0.0495), reflecting an improvement in available lysine in the mixed meal due to increased lysine intake. CONCLUSIONS Although the bioavailability of lysine in sorghum is high, its lysine content is limiting. Complementation with lentils in a 1:1 ratio is recommended to achieve the lysine requirement for adult men consuming a sorghum-based diet. This trial was registered at clinicaltrials.gov as NCT03411005.
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Affiliation(s)
- Alyssa Paoletti
- Research Institute, Hospital for Sick Children, Toronto, Ontario, Canada
| | - Abrar Fakiha
- Research Institute, Hospital for Sick Children, Toronto, Ontario, Canada
| | - Zujaja Tul-Noor
- Research Institute, Hospital for Sick Children, Toronto, Ontario, Canada
| | - Paul B Pencharz
- Research Institute, Hospital for Sick Children, Toronto, Ontario, Canada,Department of Nutritional Sciences, University of Toronto, Toronto, Ontario, Canada,Department of Paediatrics, University of Toronto, Toronto, Ontario, Canada,Department of Agricultural, Food and Nutritional Sciences, University of Alberta, Edmonton, Alberta, Canada
| | - Crystal L Levesque
- Department of Animal Science, South Dakota State University, Brookings, South Dakota, USA
| | - Ronald O Ball
- Department of Nutritional Sciences, University of Toronto, Toronto, Ontario, Canada,Department of Agricultural, Food and Nutritional Sciences, University of Alberta, Edmonton, Alberta, Canada
| | - Dehan Kong
- Department of Statistical Sciences, University of Toronto, Toronto, Ontario, Canada
| | - Rajavel Elango
- Department of Pediatrics, School of Population and Public Health, University of British Columbia, Vancouver, BC, Canada,BC Children's Hospital Research Institute, BC Children's Hospital, Vancouver, BC, Canada
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Szwiega S, Pencharz PB, Rafii M, Lebarron M, Chang J, Ball RO, Kong D, Xu L, Elango R, Courtney-Martin G. Dietary leucine requirement of older men and women is higher than current recommendations. Am J Clin Nutr 2020; 113:410-419. [PMID: 33330915 PMCID: PMC7851820 DOI: 10.1093/ajcn/nqaa323] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2020] [Accepted: 10/12/2020] [Indexed: 12/16/2022] Open
Abstract
BACKGROUND Current national (34 mg . kg-1 . d-1) and international (39 mg kg-1 . d-1) recommendations for leucine in older adults are based on data from young adults. Evidence suggests that the leucine requirements of older adults are higher than those of young adults. OBJECTIVE The objective of the current study was to directly determine the leucine requirements in healthy older adult male and female study participants aged >60 y. METHODS Leucine requirement was determined using the indicator amino acid oxidation method (IAAO) with l-[1-13C]phenylalanine as the indicator. Sixteen older adults (n = 7 male and n = 9 female participants) were randomly assigned to receive 3 to 7 leucine intakes from 20 to 120 mg . kg-1 . d-1. The rate of release of 13CO2 from l-[1-13C]phenylalanine oxidation was measured, and breakpoint analysis was used to estimate the leucine requirement. The 95% CI was calculated using the parametric bootstrap method. RESULTS The mean leucine requirement for male participants was 77.8 mg . kg-1 . d-1 (upper 95% CI: 81.0) and for female participants, it was 78.2 mg . kg-1 . d-1 (upper 95% CI: 82.0) with no sex effect based on body weight. The data were therefore combined to yield a mean of 78.5 mg . kg-1 d-1 (upper 95% CI: 81.0 mg . kg-1 . d-1 ) for both sexes. On the basis of fat-free mass, the mean ± SEM leucine requirements were 115 ± 3.2 and 127 ± 2.4 mg . kg-1 . d-1 for male and female participants, respectively (P < 0.005). CONCLUSIONS The estimated leucine requirement of older adults is more than double the amount in current recommendations. These data suggest that leucine could be a limiting amino acid in the diet of older adults consuming the current RDA for protein and those consuming a plant-based diet. In view of the functional and structural role of leucine, especially its importance in muscle protein synthesis, current leucine recommendations of older adults should be revised. This trial was registered at clinicaltrials.gov as NCT03506126.
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Affiliation(s)
- Sylwia Szwiega
- Research Institute, Hospital for Sick Children, Toronto, Ontario, Canada
| | - Paul B Pencharz
- Research Institute, Hospital for Sick Children, Toronto, Ontario, Canada,Department of Nutritional Sciences, University of Toronto, Toronto, Ontario, Canada,Department of Paediatrics, University of Toronto, Toronto, Ontario, Canada
| | - Mahroukh Rafii
- Research Institute, Hospital for Sick Children, Toronto, Ontario, Canada
| | - Mackenzie Lebarron
- Research Institute, Hospital for Sick Children, Toronto, Ontario, Canada
| | - Jessica Chang
- Research Institute, Hospital for Sick Children, Toronto, Ontario, Canada
| | - Ronald O Ball
- Department of Agriculture, Food, and Nutritional Science, University of Alberta, Edmonton, Alberta, Canada
| | - Dehan Kong
- Department of Statistical Sciences, University of Toronto, Toronto, Ontario, Canada
| | - Libai Xu
- Department of Statistical Sciences, University of Toronto, Toronto, Ontario, Canada
| | - Rajavel Elango
- Department of Pediatrics, School of Population and Public Health, University of British Columbia, Vancouver, BC, Canada,BC Children's Hospital Research Institute, BC Children's Hospital, Vancouver, BC, Canada
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10
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Caballero K, Mandal R, Pratap-Singh A, Kitts DD, Ball RO, Pencharz PB, Courtney-Martin G, Elango R. Lysine Bioavailability in School-Age Children Consuming Rice Is Reduced by Starch Retrogradation. J Nutr 2020; 150:3208-3215. [PMID: 33025006 DOI: 10.1093/jn/nxaa276] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2020] [Revised: 07/07/2020] [Accepted: 08/17/2020] [Indexed: 11/13/2022] Open
Abstract
BACKGROUND Rice is one of the most commonly consumed cereal grains and is part of staple diets in the majority of the world. However, it is regarded as an incomplete protein, with lysine being a limiting amino acid. OBJECTIVES Our objectives were to determine the bioavailability of lysine in school-age children consuming cooked white rice and to assess the effect of rice starch retrogradation. METHODS Bioavailability or metabolic availability (MA) of lysine was determined using the indicator amino acid oxidation (IAAO) method in a repeated-measures design. Six healthy school-age children (3 boys, 3 girls) with a mean ± SD age of 6.8 ± 0.98 y randomly received 4 crystalline l-lysine intakes (2, 6, 10, 14 mg · kg-1 · d-1), and 5 rice intakes to provide lysine at 8, 11, or 14 mg · kg-1 · d-1. The 14 mg · kg-1 · d-1 intakes were measured twice as warm rice and once as cold rice (to assess the impact of starch retrogradation on MA). Diets provided protein at 1.5 g · kg-1 · d-1 and calories at 1.7 times the participant's measured resting energy requirement, and were isonitrogenous. Breath samples were collected at baseline and during an isotopic steady state for 13C enrichment measurement. The MA of lysine from rice was determined by comparing the IAAO response of rice with l-lysine using the slope-ratio and single intake methods. Starch retrogradation was characterized using differential scanning calorimetry. RESULTS MA of lysine in warm rice measured in school-age children was 97.5% and was similar to a repeated rice study (97.1%) within the same study population. MA of lysine was reduced significantly (P < 0.05) to 86.1% when the cooked rice was consumed cold, which corresponded to detectable starch retrogradation. CONCLUSIONS To our knowledge, this is the first study to measure the MA of lysine from rice in school-age children. Although the bioavailability of lysine from rice is high, it can be reduced by retrogradation of its starch component.This trial was registered at clinicaltrials.gov as NCT04135040.
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Affiliation(s)
- Katia Caballero
- Food, Nutrition, and Health, Faculty of Land and Food Systems, University of British Columbia, Vancouver, British Columbia, Canada.,BC Children's Hospital Research Institute, Vancouver, British Columbia, Canada
| | - Ronit Mandal
- Food, Nutrition, and Health, Faculty of Land and Food Systems, University of British Columbia, Vancouver, British Columbia, Canada
| | - Anubhav Pratap-Singh
- Food, Nutrition, and Health, Faculty of Land and Food Systems, University of British Columbia, Vancouver, British Columbia, Canada
| | - David D Kitts
- Food, Nutrition, and Health, Faculty of Land and Food Systems, University of British Columbia, Vancouver, British Columbia, Canada
| | - Ronald O Ball
- Department of Agricultural, Food, and Nutritional Sciences, University of Alberta, Edmonton, Alberta, Canada
| | - Paul B Pencharz
- Research Institute, Hospital for Sick Children, Toronto, Ontario, Canada
| | | | - Rajavel Elango
- Food, Nutrition, and Health, Faculty of Land and Food Systems, University of British Columbia, Vancouver, British Columbia, Canada.,BC Children's Hospital Research Institute, Vancouver, British Columbia, Canada.,Department of Pediatrics, University of British Columbia, Vancouver, British Columbia, Canada.,School of Population and Public Health, University of British Columbia, Vancouver, British Columbia, Canada
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11
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Ennis MA, Ong AJ, Lim K, Ball RO, Pencharz PB, Courtney-Martin G, Elango R. Dietary Aromatic Amino Acid Requirements During Early and Late Gestation in Healthy Pregnant Women. J Nutr 2020; 150:3224-3230. [PMID: 33188409 PMCID: PMC7726121 DOI: 10.1093/jn/nxaa317] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2020] [Revised: 08/07/2020] [Accepted: 09/22/2020] [Indexed: 11/13/2022] Open
Abstract
BACKGROUND Phenylalanine and tyrosine (referred to as total aromatic amino acids; TAAs) are essential for protein synthesis, and are precursors for important catecholamines. Current estimated average requirement (EAR) recommendations for TAA during pregnancy are 36 mg·kg-1·d-1, and has not been experimentally determined. OBJECTIVES The aim was to determine TAA requirements (dietary phenylalanine in the absence of tyrosine) during early and late gestation using the indicator amino acid oxidation (IAAO, with L-[1-13C]leucine) technique. METHODS Nineteen healthy pregnant women (age 22-38 y) were studied at a range of phenylalanine intakes (5 to 100 mg·kg-1·d-1) in early (13-19 wk) and/or late (33-39 wk) pregnancy for a total of 51 study days. Graded test intakes were provided as 8 hourly isonitrogenous and isocaloric meals. Breath samples were collected for 13C enrichment analysis on an isotope ratio mass spectrometer. A plasma sample was collected and analyzed for phenylalanine and tyrosine concentrations on an amino acid analyzer. The TAA requirement in early and late pregnancy was calculated using 2-phase linear regression crossover analysis that identified breakpoints in 13CO2 production (the requirement) in response to phenylalanine intakes. RESULTS TAA requirement during early pregnancy was 44 mg·kg-1·d-1 (95% CI: 28.3, 58.8) and during late pregnancy was 50 mg·kg-1·d-1 (95% CI: 36.1, 63.1). In early and late pregnancy, plasma phenylalanine and tyrosine concentrations rose linearly in response to graded phenylalanine intakes. CONCLUSIONS Our results suggest that the current EAR of 36 mg·kg-1·d-1 for TAAs is underestimated. When compared with results previously determined in nonpregnant adults, early pregnancy requirements were similar (43 compared with 44 mg·kg-1·d-1, respectively). During late pregnancy, a 14% higher TAA requirement was observed when compared with early pregnancy. The results from this study have potential implications for creating gestation stage-specific TAA recommendations.
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Affiliation(s)
- Madeleine A Ennis
- British Columbia Children's Hospital Research Institute, British Columbia Children's Hospital, Vancouver, Canada,Department of Pediatrics, University of British Columbia, Vancouver, Canada
| | - Anna-Joy Ong
- British Columbia Children's Hospital Research Institute, British Columbia Children's Hospital, Vancouver, Canada
| | - Kenneth Lim
- Department of Obstetrics and Gynecology, British Columbia Women's Hospital, Vancouver, Canada
| | - Ronald O Ball
- Department of Agricultural, Food and Nutritional Sciences, University of Alberta, Edmonton, Canada
| | - Paul B Pencharz
- Research Institute, The Hospital for Sick Children, Toronto, Canada,Department of Nutritional Sciences, University of Toronto, Toronto, Canada,Department of Pediatrics, University of Toronto, Toronto, Canada
| | - Glenda Courtney-Martin
- Research Institute, The Hospital for Sick Children, Toronto, Canada,Department of Nutritional Sciences, University of Toronto, Toronto, Canada
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12
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Fakiha A, Tul-Noor Z, Paoletti A, Pencharz PB, Ball RO, Levesque CL, Elango R, Courtney-Martin G. Bioavailable Lysine, Assessed in Healthy Young Men Using Indicator Amino Acid Oxidation, is Greater when Cooked Millet and Stewed Canadian Lentils are Combined. J Nutr 2020; 150:2729-2737. [PMID: 32840580 DOI: 10.1093/jn/nxaa227] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2020] [Revised: 05/01/2020] [Accepted: 07/09/2020] [Indexed: 01/04/2023] Open
Abstract
BACKGROUND Pearl millet is the chief source of energy in the diet in some developing regions, but has a limited amount of indispensable amino acid lysine. Complementation with pulses like lentils can improve the protein quality of millet diets, but the knowledge of lysine bioavailability (BA) in millet and lentils is lacking. OBJECTIVES The study objectives were to determine the BA of lysine in millet and lentils separately and to assess the effect of complementation of millet and lentils in a mixed meal format. METHODS We studied 9 healthy young men (≤30 y; BMI <25) in a repeated-measure design using the indicator amino acid oxidation (IAAO) method, with L-[1-13C] phenylalanine as the indicator. Each subject completed 7 or 8 experiments in random order. On the reference diet, subjects received 4 graded levels of L-lysine (5, 8, 12, and 15 mg·kg-1.d-1) from a crystalline amino acid mixture patterned after egg protein; on the test diets, they received 3 levels of lysine (10, 12, and 15 mg·kg-1.d-1) from either steamed millet or stewed lentils; and on the complementation diet, they received 1 level of lysine from a mixed meal of steamed millet and stewed lentils. The BA of lysine and the effect of complementation were assessed by comparing the IAAO responses to the test diets and the complementation diet with the IAAO response to L-lysine intakes in the reference protein, using the slope ratio method. RESULTS The BA of lysine was 97% from millet and 80% from lentils. Complementation of steamed millet with stewed lentils decreased the oxidation of L-[1-13C] phenylalanine by 27% (P < 0.05), signifying improved quality of the combined millet and lentil protein. CONCLUSIONS Lysine has high BA but is still limiting in steamed pearl millet. Complementation with lentils in a 2:1 ratio is recommended to meet the lysine and protein requirements for adult men consuming a millet-based diet. This trial was registered at clinicaltrials.gov as NCT03674736 and NCT03339167.
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Affiliation(s)
- Abrar Fakiha
- Research Institute, Hospital for Sick Children, Toronto, Ontario, Canada
| | - Zujaja Tul-Noor
- Research Institute, Hospital for Sick Children, Toronto, Ontario, Canada
| | - Alyssa Paoletti
- Research Institute, Hospital for Sick Children, Toronto, Ontario, Canada
| | - Paul B Pencharz
- Research Institute, Hospital for Sick Children, Toronto, Ontario, Canada.,Departments of Nutritional Sciences, University of Toronto, Toronto, Ontario, Canada.,Department of Paediatrics, University of Toronto, Toronto, Ontario, Canada.,Department of Agriculture, Food and Nutritional Science, University of Alberta, Edmonton, Alberta, Canada
| | - Ronald O Ball
- Departments of Nutritional Sciences, University of Toronto, Toronto, Ontario, Canada.,Department of Agriculture, Food and Nutritional Science, University of Alberta, Edmonton, Alberta, Canada
| | - Crystal L Levesque
- Department of Animal Science, South Dakota State University, Brookings, SD, USA
| | - Rajavel Elango
- Department of Pediatrics, School of Population and Public Health, University of British Columbia, Vancouver, British Columbia, Canada.,Research Institute, British Columbia Children's Hospital, Vancouver, British Columbia, Canada
| | - Glenda Courtney-Martin
- Research Institute, Hospital for Sick Children, Toronto, Ontario, Canada.,Departments of Nutritional Sciences, University of Toronto, Toronto, Ontario, Canada.,Kinesiology & Physical Education, University of Toronto, Toronto, Ontario, Canada
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13
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Cooper L, Ball RO, Pencharz PB, Sakai R, Elango R. Dispensable Amino Acids, except Glutamine and Proline, Are Ideal Nitrogen Sources for Protein Synthesis in the Presence of Adequate Indispensable Amino Acids in Adult Men. J Nutr 2020; 150:2398-2404. [PMID: 32879983 DOI: 10.1093/jn/nxaa180] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2020] [Revised: 03/11/2020] [Accepted: 06/03/2020] [Indexed: 11/13/2022] Open
Abstract
BACKGROUND Nutritionally, there is a dietary requirement for indispensable amino acids (IAAs) but also a requirement for nitrogen (N) intake for the de novo synthesis of the dispensable amino acids (DAAs). It has been suggested that there might be a dietary requirement for specific DAAs. OBJECTIVES Experiment 1 tested whether 9 of the DAAs (Ala, Arg, Asn, Asp, Gln, Glu, Gly, Pro, Ser) are ideal N sources using the indicator amino acid oxidation (IAAO) technique. Experiment 2 examined whether there is a dietary requirement for Glu in adult men. METHODS Seven healthy men (aged 20-24 y) participated in 11 or 2 test diet intakes, in experiment 1 and 2, respectively, in a repeated measures design. In experiment 1, a base diet consisting of the IAA provided at the RDA was compared with test intakes with the base diet plus addition of individual DAAs to meet a 50:50 ratio of IAA:DAA on an N basis. In experiment 2, the diets corresponded to the amino acid pattern present in egg protein, in which all Glu and Gln was present as Glu, or removed, with Ser used to make the diets isonitrogenous. On each study day the IAAO protocol with l-[1-13C]phenylalanine was used to measure whole-body protein synthesis. RESULTS In experiment 1, repeated measures ANOVA with post hoc multiple comparisons showed that 7 of the 9 DAAs (Ala, Arg, Asn, Asp, Glu, Gly, Ser) decreased IAAO significantly (P < 0.05) compared with base IAA diet, the exceptions being Gln and Pro. In experiment 2, a paired t test did not find significant (P > 0.05) differences in the IAAO in response to removal and replacement of Glu intake. CONCLUSIONS The results suggest that in healthy men most DAAs are ideal N sources for protein synthesis, in the presence of adequate IAAs, and that endogenous synthesis of Glu is sufficient.Registered clinicaltrials.gov identifier: NCT02009917.
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Affiliation(s)
- Leah Cooper
- BC Children's Hospital Research Institute, BC Children's Hospital, Vancouver, British Columbia, Canada.,Research Institute, Hospital for Sick Children, Toronto, Ontario, Canada
| | - Ronald O Ball
- Department of Agricultural, Food & Nutritional Science, University of Alberta, Edmonton, Alberta, Canada
| | - Paul B Pencharz
- Research Institute, Hospital for Sick Children, Toronto, Ontario, Canada
| | - Ryosei Sakai
- Research Institute for Bioscience Products & Fine Chemicals, Ajinomoto Co. Inc., Kawasaki-Shi, Japan
| | - Rajavel Elango
- BC Children's Hospital Research Institute, BC Children's Hospital, Vancouver, British Columbia, Canada.,Department of Pediatrics, University of British Columbia, Vancouver, British Columbia, Canada.,School of Population and Public Health, University of British Columbia, Vancouver, British Columbia, Canada
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14
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Rafii M, Pencharz PB, Ball RO, Tomlinson C, Elango R, Courtney-Martin G. Bioavailable Methionine Assessed Using the Indicator Amino Acid Oxidation Method Is Greater When Cooked Chickpeas and Steamed Rice Are Combined in Healthy Young Men. J Nutr 2020; 150:1834-1844. [PMID: 32271919 DOI: 10.1093/jn/nxaa086] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2019] [Revised: 02/19/2020] [Accepted: 03/10/2020] [Indexed: 11/12/2022] Open
Abstract
BACKGROUND In general, pulse protein is limiting in the indispensable amino acid methionine, and antinutritional factors in pulses can affect methionine bioavailability. Complementation with grains such as rice can improve pulse protein quality, but knowledge of methionine bioavailability in pulses and grains is necessary to correct for available methionine when planning and assessing dietary protein intake. OBJECTIVES The study objectives were to determine the bioavailability of methionine in rice and chickpeas separately and to assess the effect of complementation of chickpeas and rice. METHODS Eleven healthy young men (<30 y, BMI <25 kg/m2) were studied in a repeated-measures design using the indicator amino acid oxidation (IAAO) method, with l-[1-13C]phenylalanine as the indicator. Each received 7 or 10 methionine intakes in random order: 4 intakes of l-methionine-0.5, 1, 2, and 3 mg⋅kg-1⋅d-1 (reference diet); 3 intakes of methionine from rice and from chickpeas; and 3 intakes from the mixed meal of chickpeas plus rice (test diets). The bioavailability of methionine and the effect of complementation were assessed by comparing the IAAO response to varying intakes of methionine in rice, in cooked Canadian chickpeas, and in rice plus chickpeas combined compared with the IAAO response to l-methionine intakes in the reference protein (crystalline amino acid mixture patterned after egg protein) using the slope ratio method. RESULTS The bioavailability of methionine from rice and from chickpeas was 100% and 63%, respectively. Complementation of cooked chickpeas with rice decreased the oxidation of l-[1-13C]phenylalanine by up to 14% (P < 0.05), suggesting an improved protein quality of the combined chickpeas plus rice protein. CONCLUSIONS When chickpeas are the main protein source in the diet of young adult men, the combination of rice and chickpeas in a 3:1 ratio is recommended to improve dietary protein quality. This trial was registered at clinicaltrials.gov as NCT03339154 and NCT03674736.
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Affiliation(s)
- Mahroukh Rafii
- Research Institute, Hospital for Sick Children, Toronto, Ontario, Canada
| | - Paul B Pencharz
- Research Institute, Hospital for Sick Children, Toronto, Ontario, Canada.,Department of Nutritional Sciences, University of Toronto, Toronto, Ontario, Canada.,Department of Paediatrics, University of Toronto, Toronto, Ontario, Canada
| | - Ronald O Ball
- Department of Nutritional Sciences, University of Toronto, Toronto, Ontario, Canada.,Department of Agriculture, Food and Nutritional Science, University of Alberta, Edmonton, Alberta, Canada
| | - Christopher Tomlinson
- Research Institute, Hospital for Sick Children, Toronto, Ontario, Canada.,Department of Nutritional Sciences, University of Toronto, Toronto, Ontario, Canada.,Department of Paediatrics, University of Toronto, Toronto, Ontario, Canada
| | - Rajavel Elango
- Department of Pediatrics, School of Population and Public Health, University of British Columbia, Vancouver, British Columbia, Canada.,BC Children's Hospital Research Institute, BC Children's Hospital, Vancouver, British Columbia, Canada
| | - Glenda Courtney-Martin
- Research Institute, Hospital for Sick Children, Toronto, Ontario, Canada.,Department of Nutritional Sciences, University of Toronto, Toronto, Ontario, Canada.,Faculty of Kinesiology & Physical Education, University of Toronto, Toronto, Ontario, Canada
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15
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Ennis MA, Rasmussen BF, Lim K, Ball RO, Pencharz PB, Courtney-Martin G, Elango R. Dietary phenylalanine requirements during early and late gestation in healthy pregnant women. Am J Clin Nutr 2020; 111:351-359. [PMID: 31758682 PMCID: PMC6997087 DOI: 10.1093/ajcn/nqz288] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2018] [Accepted: 10/28/2019] [Indexed: 11/12/2022] Open
Abstract
BACKGROUND Phenylalanine is an indispensable amino acid and, via tyrosine, is the precursor for the neurotransmitters dopamine, norepinephrine, and epinephrine. Currently, dietary requirements for phenylalanine during pregnancy are unknown. OBJECTIVES This study's aim was to determine phenylalanine requirements (in the presence of excess tyrosine) during early and late gestation using direct amino acid oxidation (DAAO; with l-[1-13C]phenylalanine) and indicator amino acid oxidation (IAAO; with l-[1-13C]leucine). METHODS Twenty-three healthy women (age: 30.4 ± 3.1 y, mean ± SD) were studied at a range of phenylalanine intakes (5.5-30.5 mg · kg-1 · d-1 in early and late pregnancy using DAAO, and 2.5-30.5 mg · kg-1 · d-1 in late pregnancy using IAAO) for a total of 76 study days. Test intakes were provided as 8 isocaloric and isonitrogenous meals with 1.5 g · kg-1 · d-1 protein and energy at 1.7 times the measured resting energy expenditure. Breath samples were analyzed on an isotope ratio mass spectrometer for 13C enrichment. Phenylalanine requirement was determined using a 2-phase linear regression crossover model to identify a breakpoint in 13CO2 production (representing the mean requirement) in response to phenylalanine intakes. RESULTS Phenylalanine requirement during early pregnancy was determined to be 15 mg · kg-1 · d-1 (95% CI: 10.4, 19.9 mg · kg-1 · d-1); during late pregnancy, it was determined to be 21 mg · kg-1 · d-1 by DAAO (95% CI: 17.4, 24.7 mg · kg-1 · d-1) and IAAO (95% CI: 10.5, 32.2 mg · kg-1 · d-1). CONCLUSIONS Our results suggest a higher requirement (40%) for phenylalanine during late pregnancy than during early pregnancy. Moreover, the early pregnancy requirements are higher than the previous adult male requirement (9.1 mg · kg-1 · d-1; 95% CI: 4.6, 13.6 mg · kg-1 · d-1), although the 95% CIs overlap. Both DAAO and IAAO methods provided similar breakpoints in late pregnancy, showing that the DAAO method was appropriate even though low phenylalanine intakes could not be tested. These results have potential implications for gestation stage-specific dietary phenylalanine recommendations in future.This trial was registered at clinicaltrials.gov as NCT02669381.
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Affiliation(s)
- Madeleine A Ennis
- BC Children's Hospital Research Institute, BC Children's Hospital, Vancouver, British Columbia, Canada
- Department of Pediatrics, University of British Columbia, Vancouver, British Columbia, Canada
| | - Betina F Rasmussen
- BC Children's Hospital Research Institute, BC Children's Hospital, Vancouver, British Columbia, Canada
- Department of Pediatrics, University of British Columbia, Vancouver, British Columbia, Canada
| | - Kenneth Lim
- BC Children's Hospital Research Institute, BC Children's Hospital, Vancouver, British Columbia, Canada
- Department of Obstetrics and Gynecology, BC Women's Hospital, Vancouver, British Columbia, Canada
| | - Ronald O Ball
- Department of Agricultural, Food and Nutritional Sciences, University of Alberta, Edmonton, Alberta, Canada
| | - Paul B Pencharz
- Research Institute, The Hospital for Sick Children, Toronto, Ontario, Canada
- Department of Nutritional Sciences, University of Toronto, Toronto, Ontario, Canada
- Department of Pediatrics, University of Toronto, Toronto, Ontario, Canada
| | - Glenda Courtney-Martin
- Research Institute, The Hospital for Sick Children, Toronto, Ontario, Canada
- Department of Nutritional Sciences, University of Toronto, Toronto, Ontario, Canada
- Faculty of Kinesiology, University of Toronto, Toronto, Ontario, Canada
| | - Rajavel Elango
- BC Children's Hospital Research Institute, BC Children's Hospital, Vancouver, British Columbia, Canada
- Department of Pediatrics, University of British Columbia, Vancouver, British Columbia, Canada
- School of Population and Public Health, University of British Columbia, Vancouver, British Columbia, Canada
- Address correspondence to RE (e-mail: )
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16
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Martin KE, Pencharz PB, Rafii M, Ball RO, Szwiega S, Elango R, Courtney-Martin G. The Phenylalanine Requirement of Elderly Men and Women Measured by Direct 13C Carbon Oxidation Method Is Similar to That of Young Adults. J Nutr 2019; 149:1776-1784. [PMID: 31271193 PMCID: PMC6768813 DOI: 10.1093/jn/nxz137] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2019] [Revised: 02/11/2019] [Accepted: 05/24/2019] [Indexed: 11/13/2022] Open
Abstract
BACKGROUND The phenylalanine requirement of the elderly is not known. Current recommendations are based on studies in young adults and are derived from a combined estimate of the total aromatic amino acids, phenylalanine, and tyrosine. OBJECTIVES The purpose of this study was to determine the dietary phenylalanine requirement of adults aged >65 y, using the direct amino acid oxidation method, by measuring the oxidation of l-[1-13C]phenylalanine to 13CO2 in response to graded phenylalanine intakes in the presence of excess tyrosine. METHODS Twelve subjects (6 men, 6 women), aged 73.8 ± 6.7 y (mean ± SD) and with a BMI (in kg/m2) of 26.4 ± 4.8 and 25.2 ± 4.4 for men and women, respectively, were randomized to phenylalanine intakes ranging from 7.20 to 40.0 mg .kg-1 .d-1 for a total of 66 studies. Study diets were isocaloric and isonitrogenous, providing protein and energy at 1.0 g .kg-1 .d-1 and 1.5 × resting energy expenditure (REE), respectively. Protein was provided as an amino acid mixture patterned after egg protein, with an excess of tyrosine and alanine to balance the nitrogen as phenylalanine intakes were varied. Two days prior to the study day, subjects were adapted to a milkshake diet providing protein at 1.0 g.kg-1 .d-1 and energy at 1.7 × REE. The mean phenylalanine requirement was determined using biphase linear regression analysis, which identified a breakpoint in the F13CO2 in response to graded phenylalanine intakes. RESULTS The mean and upper 95% CIs (approximating the recommended dietary allowance) of phenylalanine requirements were estimated to be 9.03 and 15.9 mg.kg-1 .d-1, respectively. CONCLUSION These results are similar to previously derived estimates of 9.1 and 13.6 mg.kg-1 .d-1 in young adult men and suggest that higher protein needs of the elderly to stimulate similar muscle protein synthesis rates as young adults are not driven by an increased requirement for phenylalanine. This trial was registered at clinicaltrials.gov as NCT02971059.
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Affiliation(s)
| | - Paul B Pencharz
- Research Institute, Hospital for Sick Children, Toronto, Canada,Department of Nutritional Sciences, University of Toronto, Toronto, Canada,Department of Pediatrics, University of Toronto, Toronto, Canada
| | - Mahroukh Rafii
- Research Institute, Hospital for Sick Children, Toronto, Canada
| | - Ronald O Ball
- Department of Nutritional Sciences, University of Toronto, Toronto, Canada,Department of Agriculture, Food, and Nutritional Science, University of Alberta, Edmonton, Canada
| | - Sylwia Szwiega
- Research Institute, Hospital for Sick Children, Toronto, Canada
| | - Rajavel Elango
- Department of Pediatrics, School of Population and Public Health, University of British Columbia, Vancouver, Canada,BC Children's Hospital Research Institute, BC Children's Hospital, Vancouver, Canada
| | - Glenda Courtney-Martin
- Research Institute, Hospital for Sick Children, Toronto, Canada,Department of Nutritional Sciences, University of Toronto, Toronto, Canada,Faculty of Kinesiology and Physical Education, University of Toronto, Toronto, Canada,Address correspondence to GC-M (e-mail: )
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Al-Mokbel A, Courtney-Martin G, Elango R, Ball RO, Pencharz PB, Tomlinson C. Tryptophan Requirement in School-Age Children Determined by the Indicator Amino Acid Oxidation Method is Similar to Current Recommendations. J Nutr 2019; 149:280-285. [PMID: 30753549 DOI: 10.1093/jn/nxy250] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2018] [Revised: 05/09/2018] [Accepted: 09/04/2018] [Indexed: 11/12/2022] Open
Abstract
BACKGROUND The requirement for dietary tryptophan in school-age children has never been empirically derived. OBJECTIVE The objective of our study was to determine the tryptophan requirement of school-age children using the indicator amino acid oxidation technique. METHODS Volunteer healthy school-age children, between 8 and 12 y, were enrolled and the oxidation of l-[13C]-phenylalanine to 13CO2 measured in response to graded intakes of dietary tryptophan. Seven children (3 boys, 4 girls) participated in the study and received randomly assigned tryptophan intakes ranging from 0.5 to 9.75 mg.kg-1.d-1 for a total of 36 studies. The diets provided energy at 1.5 times each subject's resting energy expenditure and were isocaloric. Protein was provided as an amino acid mixture on the basis of the egg protein pattern, and phenylalanine and tyrosine were maintained constant across the protein intake concentrations at 25 and 40 mg.kg-1.d-1. All subjects were adapted for 2 d before the study day to a protein intake of 1.5 g.kg-1.d-1. The mean tryptophan requirement was determined by applying a mixed-effect change-point regression analysis to F13CO2 (label tracer oxidation in 13CO2 breath) which identified a breakpoint in the F13CO2 in response to graded amounts of tryptophan. RESULTS The mean [estimated average requirement (EAR)] and upper 95% CI, (approximating the RDA) of tryptophan requirements were estimated to be 4.7 and 6.1 mg.kg-1.d-1, respectively. CONCLUSION Our results are similar to the current recommended EAR and RDA of 5 and 6 mg.kg-1.d-1 for healthy growing children based on the factorial calculation. Clinical Trials Registration No. NCT02018588.
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Affiliation(s)
- Abeer Al-Mokbel
- Research Institute, Hospital for Sick Children, Toronto, Ontario, Canada
| | - Glenda Courtney-Martin
- Research Institute, Hospital for Sick Children, Toronto, Ontario, Canada.,Faculty of Kinesiology & Physical Education.,Departments of Nutritional Sciences
| | - Rajavel Elango
- Department of Pediatrics, School of Population and Public Health, University of British Columbia, Vancouver, British Columbia, Canada.,Child & Family Research Institute, BC Children's Hospital, Vancouver, British Columbia, Canada
| | - Ronald O Ball
- Departments of Nutritional Sciences.,Department of Agriculture, Food and Nutritional Science, University of Alberta, Edmonton, Alberta, Canada
| | - Paul B Pencharz
- Research Institute, Hospital for Sick Children, Toronto, Ontario, Canada.,Departments of Nutritional Sciences.,Paediatrics, University of Toronto, Toronto, Ontario, Canada
| | - Christopher Tomlinson
- Research Institute, Hospital for Sick Children, Toronto, Ontario, Canada.,Departments of Nutritional Sciences
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18
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Rafii M, Elango R, Ball RO, Pencharz PB, Courtney-Martin G. Metabolic Availability of the Limiting Amino Acids Lysine and Tryptophan in Cooked White African Cornmeal Assessed in Healthy Young Men Using the Indicator Amino Acid Oxidation Technique. J Nutr 2018; 148:917-924. [PMID: 29741697 DOI: 10.1093/jn/nxy039] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2017] [Accepted: 02/09/2018] [Indexed: 11/13/2022] Open
Abstract
Background Maize is a staple food in many regions of the world, particularly in Africa and Latin America. However, maize protein is limiting in the indispensable amino acids lysine and tryptophan, making its protein of poor quality. Objective The main objective of this study was to determine the protein quality of white African cornmeal by determining the metabolic availability (MA) of lysine and tryptophan. Methods To determine the MA of lysine, 4 amounts of l-lysine (10, 13, 16, and 18 mg · kg-1 · d-1 totaling 28.6%, 37.1%, 45.7%, and 51.4% of the mean lysine requirement of 35 mg · kg-1 · d-1, respectively) were studied in 6 healthy young men in a repeated-measures design. To determine the MA of tryptophan, 4 amounts of l-tryptophan (0.5, 1, 1.5, and 2 mg · kg-1 · d-1 totaling 12.5%, 25.0%, 37.5%, and 50.0% of the mean tryptophan requirement of 4 mg · kg-1 · d-1, respectively) were studied in 7 healthy young men in a repeated-measures design. The MAs of lysine and tryptophan were estimated by comparing the indicator amino acid oxidation (IAAO) response with varying intakes of lysine and tryptophan in cooked white cornmeal compared with the IAAO response to l-lysine and l-tryptophan intakes in the reference protein (crystalline amino acid mixture patterned after egg protein) with the use of the slope ratio method. Results The MAs of lysine and tryptophan from African cooked white cornmeal were 71% and 80%, respectively. Conclusion Our study provides a robust estimate of the availability of lysine and tryptophan in African white maize to healthy young men. This estimate provides a basis for postproduction fortification or supplementation of maize-based diets. This trial was registered at www.clinicaltrials.gov as NCT02402179.
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Affiliation(s)
- Mahroukh Rafii
- Research Institute, The Hospital for Sick Children, Toronto, Ontario, Canada
| | - Rajavel Elango
- Department of Pediatrics, School of Population and Public Health, University of British Columbia, Vancouver, British Columbia, Canada.,BC Children's Hospital Research Institute, BC Children's Hospital, Vancouver, British Columbia, Canada
| | - Ronald O Ball
- Departments of Nutritional Sciences and Pediatrics, and Faculty of Kinesiology and Physical Education, University of Toronto, Toronto, Ontario, Canada.,Department of Agriculture, Food, and Nutritional Science, University of Alberta, Edmonton, Alberta, Canada
| | - Paul B Pencharz
- Research Institute, The Hospital for Sick Children, Toronto, Ontario, Canada.,Departments of Nutritional Sciences and Pediatrics, and Faculty of Kinesiology and Physical Education, University of Toronto, Toronto, Ontario, Canada.,Departments of Pediatrics, and Faculty of Kinesiology and Physical Education, University of Toronto, Toronto, Ontario, Canada.,Department of Agriculture, Food, and Nutritional Science, University of Alberta, Edmonton, Alberta, Canada
| | - Glenda Courtney-Martin
- Research Institute, The Hospital for Sick Children, Toronto, Ontario, Canada.,Departments of Nutritional Sciences and Pediatrics, and Faculty of Kinesiology and Physical Education, University of Toronto, Toronto, Ontario, Canada.,Departments of Faculty of Kinesiology and Physical Education, University of Toronto, Toronto, Ontario, Canada
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19
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Payne M, Stephens T, Lim K, Ball RO, Pencharz PB, Elango R. Lysine Requirements of Healthy Pregnant Women are Higher During Late Stages of Gestation Compared to Early Gestation. J Nutr 2018; 148:94-99. [PMID: 29378056 DOI: 10.1093/jn/nxx034] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2017] [Accepted: 11/07/2017] [Indexed: 11/13/2022] Open
Abstract
Background Lysine is the first limiting amino acid in cereal proteins and is found mainly in animal-derived products. Current Dietary Reference Intake (DRI) recommendations extrapolate lysine requirements during pregnancy from nonpregnant adult data, and may underestimate true requirements. Objective Our objective is to define a quantitative lysine requirement in healthy pregnant women and to determine whether requirements vary between 2 phases of gestation. Methods Fourteen pregnant women in early (12-19 wk) and 19 women in late (33-39 wk) gestation were studied using the indicator amino acid oxidation technique. Individual lysine intakes (6-84 mg · kg-1 · d-1, deficient to excess) were tested on each study day as a crystalline amino acid mixture based on egg protein composition. Isonitrogenous diets maintained protein intake at 1.5 g · kg-1 · d-1 and calorie intake at 1.7 times resting energy expenditure during each study day. Phenylalanine and tyrosine intakes were held constant across all lysine intakes. Breath and urine samples were collected at baseline and isotopic steady state. Lysine requirements were determined by measuring the oxidation of L-[1-13C]-phenylalanine to 13CO2 (F13CO2). Biphase linear regression crossover analysis was used to determine a breakpoint (which represents the estimated average requirement, EAR) in F13CO2. Results The EAR for lysine during early gestation was determined to be 36.6 mg · kg-1 · d-1 (R2 = 0.484, upper 95% CI = 46.2 mg · kg-1 · d-1), similar to an earlier adult requirement of 36 mg · kg-1 · d-1. The EAR for lysine during late gestation was determined to be 50.3 mg · kg-1 · d-1 (R2 = 0.664, upper 95% CI = 60.4 mg · kg-1 · d-1), 23% higher than the current pregnancy DRI EAR recommendation of 41 mg · kg-1 · d-1. Conclusions Our results suggest that lysine requirements are higher during late gestation compared to early gestation, and that current dietary lysine recommendations during late stages of pregnancy may be underestimated. The results have implications for populations consuming cereal-based diets as their primary source of protein. This trial was registered at clinicaltrials.gov as NCT01776931.
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Affiliation(s)
- Magdalene Payne
- BC Children's Hospital Research Institute, Vancouver, British Columbia, Canada.,Pediatrics, Obstetrics and Gynecology, and School of Population and Public Health, University of British Columbia, British Columbia, Canada
| | - Trina Stephens
- BC Children's Hospital Research Institute, Vancouver, British Columbia, Canada.,Pediatrics, Obstetrics and Gynecology, and School of Population and Public Health, University of British Columbia, British Columbia, Canada
| | - Kenneth Lim
- BC Children's Hospital Research Institute, Vancouver, British Columbia, Canada.,Obstetrics and Gynecology, and School of Population and Public Health, University of British Columbia, British Columbia, Canada
| | - Ronald O Ball
- Department of Agricultural, Food and Nutritional Science, University of Alberta, Edmonton, Alberta, Canada
| | - Paul B Pencharz
- The Research Institute, Hospital for Sick Children, 555 University Avenue, Toronto, Ontario, Canada
| | - Rajavel Elango
- BC Children's Hospital Research Institute, Vancouver, British Columbia, Canada.,Pediatrics, Obstetrics and Gynecology, and School of Population and Public Health, University of British Columbia, British Columbia, Canada.,School of Population and Public Health, University of British Columbia, British Columbia, Canada
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20
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Shoveller AK, Danelon JJ, Atkinson JL, Davenport GM, Ball RO, Pencharz PB. Calibration and validation of a carbon oxidation system and determination of the bicarbonate retention factor and the dietary phenylalanine requirement, in the presence of excess tyrosine, of adult, female, mixed-breed dogs,. J Anim Sci 2017; 95:2917-2927. [PMID: 28727110 DOI: 10.2527/jas.2017.1535] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Carbon oxidation methods have been used as rapid and sensitive methods to determine whole-body AA requirements in multiple species. The objectives of the current studies were to validate complete CO recovery, determine the bicarbonate retention factor, and estimate the Phe requirement, in the presence of excess Tyr, in adult dogs using the direct oxidation technique. In this series of studies, 2 oxidation chambers were constructed and calibrated to ensure accurate collection of breath CO. First, 104.6 ± 7.1% CO was recovered from chambers and suggests that the chambers were appropriately designed for complete and efficient CO recovery. Second, we determined bicarbonate retention in 5 dogs using repeated oral dosing of a bicarbonate tracer (NaHCO) with small meals. At isotopic and physiological steady state, 102.5 ± 2.6% of the delivered NaHCO was recovered in breath. Third, the Phe requirement, when Tyr was supplied in excess, was determined by the rate of appearance of CO in the breath (CO). Dogs ( = 5) were fed test diets with different concentrations of Phe ranging from deficient to excessive for 2 d prior to conducting the tracer studies. The mean Phe requirement (when Tyr was supplied in excess) was 0.535% of diet (upper 95% confidence interval = 0.645% diet) on an as-fed basis or 0.575% of diet (upper 95% confidence interval = 0.694% of diet) on a DM basis and was based on a calculated (modified Atwater calculation) dietary ME density of 3.73 Mcal/kg DM. These data support the use of carbon oxidation methods and oral dosing of isotope to measure whole-body requirements of indispensable AA in adult dogs and suggest the current recommendations may be low.
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21
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Elango R, Humayun MA, Turner JM, Rafii M, Langos V, Ball RO, Pencharz PB. Total Sulfur Amino Acid Requirements Are Not Altered in Children with Chronic Renal Insufficiency, but Minimum Methionine Needs Are Increased. J Nutr 2017; 147:1954-1959. [PMID: 28855417 DOI: 10.3945/jn.116.244301] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2016] [Revised: 01/18/2017] [Accepted: 07/31/2017] [Indexed: 11/14/2022] Open
Abstract
Background: The total sulfur amino acid (TSAA) and minimum Met requirements have been previously determined in healthy children. TSAA metabolism is altered in kidney disease. Whether TSAA requirements are altered in children with chronic renal insufficiency (CRI) is unknown.Objective: We sought to determine the TSAA (Met in the absence of Cys) requirements and minimum Met (in the presence of excess Cys) requirements in children with CRI.Methods: Five children (4 boys, 1 girl) aged 10 ± 2.6 y with CRI were randomly assigned to receive graded intakes of Met (0, 5, 10, 15, 25, and 35 mg · kg-1 · d-1) with no Cys in the diet. Four of the children (3 boys, 1 girl) were then randomly assigned to receive graded dietary intakes of Met (0, 2.5, 5, 7.5, 10, and 15 mg · kg-1 · d-1) with 21 mg · kg-1 · d-1 Cys. The mean TSAA and minimum Met requirements were determined by measuring the oxidation of l-[1-13C]Phe to 13CO2 (F13CO2). A 2-phase linear-regression crossover analysis of the F13CO2 data identified a breakpoint at minimal F13CO2 Urine samples collected from all study days and from previous studies of healthy children were measured for sulfur metabolites.Results: The mean and population-safe (upper 95% CI) intakes of TSAA and minimum Met in children with CRI were determined to be 12.6 and 15.9 mg · kg-1 · d-1 and 7.3 and 10.9 mg · kg-1 · d-1, respectively. In healthy school-aged children the mean and upper 95% CI intakes of TSAA and minimum Met were determined to be 12.9 and 17.2 mg · kg-1 · d-1 and 5.8 and 7.3 mg · kg-1 · d-1, respectively. A comparison of the minimum Met requirements between healthy children and children with CRI indicated significant (P < 0.05) differences.Conclusion: These results suggest that children with CRI have a similar mean and population-safe TSAA to that of healthy children, suggesting adequate Cys synthesis via transsulfuration, but higher minimum Met requirement, suggesting reduced remethylation rates.
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Affiliation(s)
- Rajavel Elango
- BC Children's Hospital Research Institute, Vancouver, British Columbia, Canada; .,Department of Pediatrics, BC Children's Hospital, University of British Columbia, Vancouver, British Columbia, Canada
| | - Mohammad A Humayun
- Research Institute, The Hospital for Sick Children, Toronto, Ontario, Canada
| | - Justine M Turner
- Research Institute, The Hospital for Sick Children, Toronto, Ontario, Canada
| | - Mahroukh Rafii
- Research Institute, The Hospital for Sick Children, Toronto, Ontario, Canada
| | - Veronika Langos
- Research Institute, The Hospital for Sick Children, Toronto, Ontario, Canada
| | - Ronald O Ball
- Department of Agricultural, Food and Nutritional Science, University of Alberta, Edmonton, Alberta, Canada; and Departments of
| | - Paul B Pencharz
- Research Institute, The Hospital for Sick Children, Toronto, Ontario, Canada.,Paediatrics and.,Nutritional Sciences, University of Toronto, Toronto, Ontario, Canada
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22
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Shoveller AK, Brunton JA, Brand O, Pencharz PB, Ball RO. N-Acetylcysteine is a Highly Available Precursor for Cysteine in the Neonatal Piglet Receiving Parenteral Nutrition. JPEN J Parenter Enteral Nutr 2017; 30:133-42. [PMID: 16517958 DOI: 10.1177/0148607106030002133] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
BACKGROUND Cysteine (CYS) is accepted as an indispensable amino acid for infants receiving parenteral nutrition (PN), and CYS is unstable in solution. Thus, developing a method to supply CYS in PN for neonates is needed. N-acetyl-L-cysteine (NAC) is stable in solution and safe for use in humans; therefore, NAC may be a means of supplying parenteral CYS. METHODS We determined the bioavailability of NAC in intravenously (IV)-fed piglets randomized to 1 of 4 diet treatments, each supplying 0.3 g/kg/d methionine and either 0.2 g/kg/d CYS (CON), 0 NAC (zeroNAC), 0.13 NAC (lowNAC), or 0.27 g/kg/d NAC (highNAC). Piglets (2 days old; 1.8 kg, n = 20) were surgically implanted with femoral and jugular catheters. On day 3 postsurgery, test diets were initiated and continued until day 8. Piglets were weighed daily. Blood was sampled 6 hours before test diet initiation and at 0, 6, 12, 18, 24, 36, 48, 60, 72, 84, 96, 108, and 120 hours. Urine was collected on ice in 24-hour sample periods. RESULTS Total mean weight gain was not different between groups; however, average daily gain in the zeroNAC and lowNAC groups declined significantly (p < .05) over the 5-day treatment period. Nitrogen retention was similar between the CON and highNAC groups, both were higher than the lowNAC group, and the zeroNAC treatment produced the lowest nitrogen retention. NAC percent retention was not different between lowNAC and highNAC and was 85.4% and 82.6%, respectively. Plasma NAC was higher in highNAC than lowNAC (p < .05). CONCLUSIONS These data demonstrate that NAC is available as a precursor for CYS to support growth and protein (nitrogen) accretion in piglets administered a parenteral solution.
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Affiliation(s)
- Anna K Shoveller
- Department of Agricultural, Food and Nutritional Science, University of Alberta, Edmonton, Alberta, Canada T6G 2P5
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23
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Turner JM, Josephson J, Field CJ, Wizzard PR, Ball RO, Pencharz PB, Wales PW. Liver Disease, Systemic Inflammation, and Growth Using a Mixed Parenteral Lipid Emulsion, Containing Soybean Oil, Fish Oil, and Medium Chain Triglycerides, Compared With Soybean Oil in Parenteral Nutrition–Fed Neonatal Piglets. JPEN J Parenter Enteral Nutr 2016; 40:973-81. [DOI: 10.1177/0148607115579711] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2014] [Accepted: 02/28/2015] [Indexed: 12/14/2022]
Affiliation(s)
- Justine M. Turner
- Department of Pediatrics, University of Alberta, Edmonton, Canada
- Department of Agricultural Food and Nutritional Science, University of Alberta, Edmonton, Canada
| | | | - Catherine J. Field
- Department of Agricultural Food and Nutritional Science, University of Alberta, Edmonton, Canada
| | | | - Ronald O. Ball
- Department of Agricultural Food and Nutritional Science, University of Alberta, Edmonton, Canada
| | - Paul B. Pencharz
- Research Institute, Hospital for Sick Children, University of Toronto, Toronto, Ontario, Canada
- Departments of Pediatrics and Nutritional Sciences, Hospital for Sick Children, University of Toronto, Toronto, Ontario, Canada
| | - Paul W. Wales
- Department of Pediatrics, University of Alberta, Edmonton, Canada
- Research Institute, Hospital for Sick Children, University of Toronto, Toronto, Ontario, Canada
- Division of General Surgery, Hospital for Sick Children, University of Toronto, Toronto, Ontario, Canada
- Group for Improvement of Intestinal Function and Treatment, Hospital for Sick Children, Toronto, Ontario, Canada
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24
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Abstract
Protein forms an essential component of a healthy diet in humans to support both growth and maintenance. During pregnancy, an exceptional stage of life defined by rapid growth and development, adequate dietary protein is crucial to ensure a healthy outcome. Protein deposition in maternal and fetal tissues increases throughout pregnancy, with most occurring during the third trimester. Dietary protein intake recommendations are based on factorial estimates because the traditional method of determining protein requirements, nitrogen balance, is invasive and undesirable during pregnancy. The current Estimated Average Requirement and RDA recommendations of 0.88 and 1.1 g · kg(-1) · d(-1), respectively, are for all stages of pregnancy. The single recommendation does not take into account the changing needs during different stages of pregnancy. Recently, with the use of the minimally invasive indicator amino acid oxidation method, we defined the requirements to be, on average, 1.2 and 1.52 g · kg(-1) · d(-1) during early (∼16 wk) and late (∼36 wk) stages of pregnancy, respectively. Although the requirements are substantially higher than current recommendations, our values are ∼14-18% of total energy and fit within the Acceptable Macronutrient Distribution Range. Using swine as an animal model we showed that the requirements for several indispensable amino acids increase dramatically during late gestation compared with early gestation. Additional studies should be conducted during pregnancy to confirm the newly determined protein requirements and to determine the indispensable amino acid requirements during pregnancy in humans.
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Affiliation(s)
- Rajavel Elango
- Child and Family Research Institute, Vancouver, British Columbia, Canada; Department of Pediatrics and School of Population and Public Health, University of British Columbia, Vancouver, British Columbia, Canada; and
| | - Ronald O Ball
- Department of Agricultural, Food, and Nutritional Science, University of Alberta, Edmonton, Alberta, Canada
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25
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Muto M, Lim D, Soukvilay A, Field C, Wizzard PR, Goruk S, Ball RO, Pencharz PB, Mi S, Curtis J, Wales PW, Turner JM. Supplemental Parenteral Vitamin E Into Conventional Soybean Lipid Emulsion Does Not Prevent Parenteral Nutrition–Associated Liver Disease in Full-Term Neonatal Piglets. JPEN J Parenter Enteral Nutr 2015; 41:575-582. [DOI: 10.1177/0148607115612030] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Affiliation(s)
- Mitsuru Muto
- Department of Pediatrics, University of Alberta, Canada
| | - David Lim
- Department of Surgery, University of Alberta, Canada
| | | | - Catherine Field
- Department of Agricultural Food and Nutritional Science, University of Alberta, Canada
| | | | - Susan Goruk
- Department of Agricultural Food and Nutritional Science, University of Alberta, Canada
| | - Ronald O. Ball
- Department of Agricultural Food and Nutritional Science, University of Alberta, Canada
| | - Paul B. Pencharz
- Department of Gastroenterology and Nutrition, Hospital for Sick Children, Toronto, Ontario, Canada
- Group for Improvement of Intestinal Function and Treatment, Hospital for Sick Children, Toronto, Ontario, Canada
| | - Si Mi
- Department of Agricultural Food and Nutritional Science, University of Alberta, Canada
| | - Jonathan Curtis
- Department of Agricultural Food and Nutritional Science, University of Alberta, Canada
| | - Paul W. Wales
- Department of Pediatrics, University of Alberta, Canada
- Group for Improvement of Intestinal Function and Treatment, Hospital for Sick Children, Toronto, Ontario, Canada
- Division of General Surgery, Hospital for Sick Children, Toronto, Ontario, Canada
| | - Justine M. Turner
- Department of Pediatrics, University of Alberta, Canada
- Department of Surgery, University of Alberta, Canada
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Pillai RR, Elango R, Ball RO, Kurpad AV, Pencharz PB. Lysine requirements of moderately undernourished school-aged Indian children are reduced by treatment for intestinal parasites as measured by the indicator amino acid oxidation technique. J Nutr 2015; 145:954-9. [PMID: 25761501 DOI: 10.3945/jn.114.208439] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2014] [Accepted: 02/19/2015] [Indexed: 11/14/2022] Open
Abstract
BACKGROUND Lysine requirements of well-nourished children from developing regions have been found to be similar to those of children from developed regions (33.5 mg · kg⁻¹ · d⁻¹). However, intestinal parasites have been shown to increase lysine requirements in undernourished adults, and it is not known if a similar phenomenon occurs in undernourished children from poor and unsanitary environments. OBJECTIVE Our objective was to measure the lysine requirement of moderately undernourished school-aged Indian children by the indicator amino acid oxidation technique before and after successful treatment for intestinal parasites. METHODS Twenty-one undernourished school-aged children (∼8 y of age) with z scores between -2 SD and -3 SD for height-for-age or weight-for-age, who tested positive for intestinal parasites, were studied before and after successful antiparasite treatment. Children were fed any 2 of 7 levels of lysine intakes (5, 15, 25, 35, 50, 65, and 80 mg · kg⁻¹ · d⁻¹) in random order. The lysine requirement was determined by applying a 2-phase linear regression crossover analysis on the fractional oxidation rate of the tracer L-[1-¹³C] phenylalanine in response to the graded lysine intakes. RESULTS The lysine requirement of undernourished children with intestinal parasite infestations was determined to be 42.8 mg · kg⁻¹ · d⁻¹ (95% CI: 32.6, 53.1 mg · kg⁻¹ · d⁻¹), and after successful antiparasitic treatment it was determined to be 35.5 mg · kg⁻¹ · d⁻¹ (95% CI: 25.5, 45.5 mg · kg⁻¹ · d⁻¹). The results were significantly different (P < 0.05), although the 95% CIs overlapped. CONCLUSIONS The lysine requirement in undernourished children is similar to that of well-nourished children, and intestinal parasitic infestation increased the lysine requirement by ∼20%.
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Affiliation(s)
- Raja R Pillai
- Division of Nutrition, St. John's Research Institute, St. John's National Academy of Health Sciences, Bangalore, India
| | - Rajavel Elango
- The Research Institute, Hospital for Sick Children, Toronto, Canada;
| | - Ronald O Ball
- Department of Agricultural, Food, and Nutritional Science, University of Alberta, Edmonton, Canada; and
| | - Anura V Kurpad
- Division of Nutrition, St. John's Research Institute, St. John's National Academy of Health Sciences, Bangalore, India
| | - Paul B Pencharz
- The Research Institute, Hospital for Sick Children, Toronto, Canada; Department of Pediatrics and Nutritional Sciences, University of Toronto, Toronto, Canada
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27
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Rafii M, Chapman K, Elango R, Campbell WW, Ball RO, Pencharz PB, Courtney-Martin G. Dietary Protein Requirement of Men >65 Years Old Determined by the Indicator Amino Acid Oxidation Technique Is Higher than the Current Estimated Average Requirement. J Nutr 2015; 146:681-687. [PMID: 26962173 DOI: 10.3945/jn.115.225631] [Citation(s) in RCA: 48] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2015] [Revised: 11/08/2015] [Accepted: 01/21/2016] [Indexed: 01/16/2023] Open
Abstract
BACKGROUND The current estimated average requirement (EAR) and RDA for protein of 0.66 and 0.8 g ⋅ kg-1 ⋅ d-1, respectively, for adults, including older men, are based on nitrogen balance data analyzed by monolinear regression. Recent studies in young men and older women that used the indicator amino acid oxidation (IAAO) technique suggest that those values may be too low. This observation is supported by 2-phase linear crossover analysis of the nitrogen balance data. OBJECTIVE The main objective of this study was to determine the protein requirement for older men by using the IAAO technique. METHODS Six men aged >65 y were studied; each individual was tested 7 times with protein intakes ranging from 0.2 to 2.0 g ⋅ kg-1 ⋅ d-1 in random order for a total of 42 studies. The diets provided energy at 1.5 times the resting energy expenditure and were isocaloric. Protein was consumed hourly for 8 h as an amino acid mixture with the composition of egg protein with L-[1-13C]phenylalanine as the indicator amino acid. The group mean protein requirement was determined by applying a mixed-effects change-point regression analysis to F13CO2 (label tracer oxidation in breath 13CO2), which identified a breakpoint in F13CO2 in response to graded intakes of protein. RESULTS The estimated protein requirement and RDA for older men were 0.94 and 1.24 g ⋅ kg-1 ⋅ d-1, respectively, which are not different from values we published using the same method in young men and older women. CONCLUSIONS The current intake recommendations for older adults for dietary protein of 0.66 g ⋅ kg-1 ⋅ d-1 for the EAR and 0.8 g ⋅ kg-1 ⋅ d-1 for the RDA appear to be underestimated by ∼30%. Future longer-term studies should be conducted to validate these results. This trial was registered at clinicaltrials.gov as NCT01948492.
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Affiliation(s)
- Mahroukh Rafii
- Research Institute, Hospital for Sick Children, Toronto, Ontario, Canada
| | - Karen Chapman
- Research Institute, Hospital for Sick Children, Toronto, Ontario, Canada
| | - Rajavel Elango
- Department of Pediatrics, School of Population and Public Health, University of British Columbia, Vancouver, British Columbia, Canada.,Child and Family Research Institute, British Columbia Children's Hospital, Vancouver, British Columbia, Canada
| | - Wayne W Campbell
- Department of Nutrition Science, Purdue University, West Lafayette, IN
| | - Ronald O Ball
- Department of Nutritional Sciences, University of Toronto, Toronto, Ontario, Canada.,Department of Pediatrics, University of Toronto, Toronto, Ontario, Canada.,Department of Agriculture, Food and Nutritional Science, University of Alberta, Edmonton, Alberta, Canada
| | - Paul B Pencharz
- Research Institute, Hospital for Sick Children, Toronto, Ontario, Canada.,Department of Nutritional Sciences, University of Toronto, Toronto, Ontario, Canada.,Department of Pediatrics, University of Toronto, Toronto, Ontario, Canada.,Department of Agriculture, Food and Nutritional Science, University of Alberta, Edmonton, Alberta, Canada
| | - Glenda Courtney-Martin
- Research Institute, Hospital for Sick Children, Toronto, Ontario, Canada.,Faculty of Kinesiology and Physical Education, University of Toronto, Toronto, Ontario, Canada
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Stephens TV, Payne M, Ball RO, Pencharz PB, Elango R. Protein requirements of healthy pregnant women during early and late gestation are higher than current recommendations. J Nutr 2015; 145:73-8. [PMID: 25527661 DOI: 10.3945/jn.114.198622] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
BACKGROUND Adequate maternal dietary protein intake is necessary for healthy pregnancy. However, current protein intake recommendations for healthy pregnant women are based on factorial calculations of nitrogen balance data derived from nonpregnant adults. Thus, an estimate of protein requirements based on pregnancy-specific data is needed. OBJECTIVE The objective of this study was to determine protein requirements of healthy pregnant women at 11-20 (early) and 31-38 (late) wk of gestation through use of the indicator amino acid oxidation method. METHODS Twenty-nine healthy women (24-37 y) each randomly received a different test protein intake (range: 0.22-2.56 g · kg(-1) · d(-1)) during each study day in early (n = 35 observations in 17 women) and late (n = 43 observations in 19 women) gestation; 7 women participated in both early and late gestation studies. The diets were isocaloric and provided energy at 1.7 × resting energy expenditure. Protein was given as a crystalline amino acid mixture based on egg protein composition, except phenylalanine and tyrosine, which were maintained constant across intakes. Protein requirements were determined by measuring the oxidation rate of L-[1-(13)C]phenylalanine to (13)CO2 (F(13)CO2). Breath and urine samples were collected at baseline and isotopic steady state. Linear regression crossover analysis identified a breakpoint (requirement) at minimal F(13)CO2 in response to different protein intakes. RESULTS The estimated average requirement (EAR) for protein in early and late gestation was determined to be 1.22 (R(2) = 0.60; 95% CI: 0.79, 1.66 g · kg(-1) · d(-1)) and 1.52 g · kg(-1) · d(-1) (R(2) = 0.63; 95% CI: 1.28, 1.77 g · kg(-1) · d(-1)), respectively. CONCLUSIONS These estimates are considerably higher than the EAR of 0.88 g · kg(-1) · d(-1) currently recommended by the Dietary Reference Intakes. To our knowledge, this study is the first to directly estimate gestational stage-specific protein requirements in healthy pregnant women and suggests that current recommendations based on factorial calculations underestimate requirements. This trial was registered at clinicaltrials.gov as NCT01784198.
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Affiliation(s)
- Trina V Stephens
- Child & Family Research Institute, British Columbia Children's Hospital, Vancouver, Canada Department of Pediatrics, University of British Columbia, Vancouver, Canada
| | - Magdalene Payne
- Child & Family Research Institute, British Columbia Children's Hospital, Vancouver, Canada Department of Pediatrics, University of British Columbia, Vancouver, Canada
| | - Ronald O Ball
- Department of Agricultural, Food, and Nutritional Science, University of Alberta, Edmonton, Canada
| | - Paul B Pencharz
- The Research Institute, Hospital for Sick Children, Toronto, Canada; and
| | - Rajavel Elango
- Child & Family Research Institute, British Columbia Children's Hospital, Vancouver, Canada Department of Pediatrics, University of British Columbia, Vancouver, Canada School of Population and Public Health, University of British Columbia, Canada
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Rafii M, Chapman K, Owens J, Elango R, Campbell WW, Ball RO, Pencharz PB, Courtney-Martin G. Dietary protein requirement of female adults >65 years determined by the indicator amino acid oxidation technique is higher than current recommendations. J Nutr 2015; 145:18-24. [PMID: 25320185 DOI: 10.3945/jn.114.197517] [Citation(s) in RCA: 79] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
BACKGROUND Studies on protein requirements in vulnerable groups such as older adults are few, and results are conflicting. OBJECTIVE The main objective of this study was to determine the protein requirements of free-living women >65 y by measuring the oxidation of l-[1-(13)C]phenylalanine to (13)CO2 in response to graded intakes of protein. METHODS Twelve subjects participated in the study, with protein intakes ranging from 0.2 to 2.0 g · kg(-1) · d(-1) for a total of 82 studies. The diets provided energy at 1.5 times each subject's resting energy expenditure and were isocaloric. Protein was given as an amino acid mixture on the basis of the egg protein pattern, except for phenylalanine and tyrosine, which were maintained constant across the protein intake amounts. All subjects were adapted for 2 d before the study day to a protein intake of 1.0 g · kg(-1) · d(-1). The mean protein requirement was determined by applying a mixed-effects change-point regression analysis to F(13)CO2 (label tracer oxidation in (13)CO2 breath), which identified a breakpoint in the F(13)CO2 in response to graded amounts of protein. RESULTS The mean estimated average requirement (EAR) and upper 95% CI (approximating the RDA) protein requirement of women >65 y were 0.96 and 1.29 g · kg(-1) · d(-1), respectively. CONCLUSION These estimates of protein requirements for older women are higher than the current EAR and RDA based on nitrogen balance data, which are 0.66 and 0.80 g · kg(-1) · d(-1), respectively. This trial was registered at clinicaltrials.gov as NCT01604980.
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Affiliation(s)
- Mahroukh Rafii
- Research Institute, Hospital for Sick Children, Toronto, Canada
| | - Karen Chapman
- Research Institute, Hospital for Sick Children, Toronto, Canada
| | - Jillian Owens
- Research Institute, Hospital for Sick Children, Toronto, Canada
| | - Rajavel Elango
- Department of Pediatrics, School of Population and Public Health, University of British Columbia, Vancouver, Canada Child & Family Research Institute, BC Children's Hospital, Vancouver, Canada
| | - Wayne W Campbell
- Department of Nutrition Science, Purdue University, West Lafayette, IN
| | - Ronald O Ball
- Departments of Nutritional Sciences and Department of Agriculture, Food, and Nutritional Science, University of Alberta, Edmonton, Canada
| | - Paul B Pencharz
- Research Institute, Hospital for Sick Children, Toronto, Canada Departments of Nutritional Sciences and Pediatrics, University of Toronto, Toronto, Canada; and Department of Agriculture, Food, and Nutritional Science, University of Alberta, Edmonton, Canada
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Myrie SB, Bertolo RF, Moehn S, Ball RO. Barley does not change threonine requirement in growing pigs fed a barley–casein-based diet compared to a casein-based diet, as determined by the indicator amino acid oxidation method. Livest Sci 2014. [DOI: 10.1016/j.livsci.2014.09.007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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Josephson J, Turner JM, Field CJ, Wizzard PR, Nation PN, Sergi C, Ball RO, Pencharz PB, Wales PW. Parenteral Soy Oil and Fish Oil Emulsions. JPEN J Parenter Enteral Nutr 2014; 39:677-87. [DOI: 10.1177/0148607114556494] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2014] [Accepted: 10/01/2014] [Indexed: 11/17/2022]
Affiliation(s)
| | - Justine M. Turner
- Department of Pediatrics, University of Alberta, Edmonton, Canada
- Department of Agricultural Food and Nutritional Science, University of Alberta, Edmonton, Canada
| | - Catherine J. Field
- Department of Agricultural Food and Nutritional Science, University of Alberta, Edmonton, Canada
| | | | - Patrick N. Nation
- Department of Laboratory Medicine & Pathology, University of Alberta, Edmonton, Canada
| | - Consolato Sergi
- Department of Laboratory Medicine & Pathology, University of Alberta, Edmonton, Canada
| | - Ronald O. Ball
- Department of Agricultural Food and Nutritional Science, University of Alberta, Edmonton, Canada
| | - Paul B. Pencharz
- Research Institute, Hospital for Sick Children, University of Toronto, Toronto, Ontario, Canada
- Departments of Pediatrics and Nutritional Sciences, Hospital for Sick Children, University of Toronto, Toronto, Ontario, Canada
| | - Paul W. Wales
- Department of Pediatrics, University of Alberta, Edmonton, Canada
- Research Institute, Hospital for Sick Children, University of Toronto, Toronto, Ontario, Canada
- Departments of Pediatrics and Nutritional Sciences, Hospital for Sick Children, University of Toronto, Toronto, Ontario, Canada
- Division of General Surgery, Hospital for Sick Children, University of Toronto, Toronto, Ontario, Canada
- Group for Improvement of Intestinal Function and Treatment, Hospital for Sick Children, Toronto, Ontario, Canada
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Affiliation(s)
- Minghua Tang
- Department of Nutrition Science Purdue University West Lafayette, IN
| | - George P McCabe
- Department of Statistics Purdue University West Lafayette, IN
| | - Rajavel Elango
- Department of Pediatrics University of British Columbia Vancouver Canada
| | - Paul B Pencharz
- Department of Pediatrics and Nutrition Science University of Toronto Toronto Canada
| | - Ronald O Ball
- Department of Agricultural, Food, and Nutrition Science University of Alberta Edmonton Canada
| | - Wayne W Campbell
- Department of Nutrition Science Purdue University 700 West State Street West Lafayette, IN 47907 E-mail:
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Tang M, McCabe GP, Elango R, Pencharz PB, Ball RO, Campbell WW. Assessment of protein requirement in octogenarian women with use of the indicator amino acid oxidation technique. Am J Clin Nutr 2014; 99:891-8. [PMID: 24429540 PMCID: PMC3953883 DOI: 10.3945/ajcn.112.042325] [Citation(s) in RCA: 65] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
BACKGROUND Data on the protein requirements of elderly adults are limited, because it is impractical to conduct repeated nitrogen balance protocols in these vulnerable humans. OBJECTIVE This study was designed to determine the dietary protein requirement of elderly women by using the recently developed minimally invasive indicator amino acid oxidation (IAAO) technique. DESIGN Six white women aged 80-87 y [mean ± SEM: 82 ± 1 y and body mass index (in kg/m²) 26 ± 2] completed a 3-d protocol 7 times. Each woman consumed an adaptation diet for 2 d and on day 3 consumed a complete test diet with a crystalline amino acid mixture containing 1 of 7 protein intakes (0.1, 0.3, 0.6, 0.9, 1.2, 1.5, or 1.8 g · kg⁻¹ · d⁻¹) tested randomly. A group-based protein requirement was assessed by using a nonlinear mixed model of protein intake and L-[1-¹³C]phenylalanine oxidation. The breakpoint, at which there was no further decline in the rate of appearance of ¹³C in the breath, was used as an index of the mean protein requirement. RESULTS The mean protein requirement (95% CI) was 0.85 (0.60, 1.09) g · kg⁻¹ · d⁻¹. This requirement is 29% higher than the current Estimated Average Requirement (EAR) for adults of 0.66 g · kg⁻¹ · d⁻¹ based on the nitrogen balance technique, although the 95% CI includes the current EAR. The corresponding adequate protein allowance of 1.15 (0.77, 1.54) g · kg⁻¹ · d⁻¹ is 44% higher, although the 95% CI includes the Recommended Dietary Allowance (RDA) of 0.80 g · kg⁻¹ · d⁻¹. CONCLUSIONS Notwithstanding uncertainty about the validity of the use of the IAAO technique to assess protein requirements, the results of this study with octogenarian women suggest that the current EAR and RDA for elderly women may be underestimated. The limitations of this short-term, noninvasive method underscore the need for new research that uses alternative experimental designs and measuring physiologic, morphologic, and health-related outcomes.
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Affiliation(s)
- Minghua Tang
- Departments of Nutrition Science (MT and WWC) and Statistics (GPM), Purdue University, West Lafayette, IN; the Department of Pediatrics, University of British Columbia, Vancouver, Canada (RE); the Department of Paediatrics and Nutrition Science, University of Toronto, Toronto, Canada (PBP); and the Department of Agricultural, Food and Nutrition Science, University of Alberta, Edmonton, Canada (ROB)
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Abstract
The objective of this study was to determine the Ile requirement in early (d 39 to 61) and late (d 89 to 109) pregnancy using the indicator AA oxidation method. The same 7 Large White × Landrace sows in their fourth parity were used in early and late pregnancy. Each sow received 6 diets based on corn, corn starch, and sugar in both early and late pregnancy at constant feed allowances (2.5 kg/d). Diets provided Ile at 20, 40, 60, 80, 100, and 120% of the Ile requirement (6.2 g/d based on the 1998 NRC) in early and 60, 80, 100, 140, 160, and 180% in late pregnancy. After determination of (13)C background in expired CO2 and plasma free Phe for 1.5 h when confined in respiration chambers, sows were fed the tracer, L[1-(13)C]Phe, a rate of 2.0 mg/(kg BW·h) over 4 h divided into eight 30-min meals. Expired CO2 and plasma free Phe were analyzed for (13)C enrichment above background. Requirements were determined as the breakpoint in 2-phase nonlinear models. Sow BW was 246.5 kg in early and 271.6 kg in late pregnancy. Daily gain of the 6 sows was similar in early (344 g/d) and late pregnancy (543 g/d). During pregnancy, sow maternal gain was 19.1 ± 4.4 kg and litters of 17.7 ± 0.8 piglets weighed 22.6 ± 0.9 kg at birth. The Ile requirement was 3.6 ± 1.2 g/d (P = 0.001) in early pregnancy with a Phe retention (-0.59 g/d) and energy retention (-0.31 MJ/d) that were not different from 0. This indicates that the fourth parity sows had requirements close to maintenance in early pregnancy. The Ile requirement in late pregnancy was 9.7 ± 1.9 g/d (P = 0.001) when sows retained 3.30 g/d of Phe and -1.45 MJ/d of energy. The greater Ile requirement in late pregnancy was probably caused by the increased conceptus growth after d 70 of pregnancy. Phenylalanine flux, oxidation, and nonoxidative disposal increased (P < 0.1) from early to late pregnancy, but body protein breakdown did not. Phenylalanine oxidation, nonoxidative disposal, and retention increased (P < 0.01) with increasing Ile intake in early pregnancy but were not affected by Ile intake in late pregnancy. Body protein breakdown did not respond to Ile intake in early or late pregnancy. Although energy retention was similar in early and late pregnancy, the respiratory quotient decreased (P = 0.047) from early (1.05) to late pregnancy (0.98), indicating lipid mobilization in late pregnancy when Ile was at or above the requirement. The results of this study show that the Ile requirement of sows increases from early to late pregnancy.
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Affiliation(s)
- D J Franco
- Department of Agriculture, Food and Nutritional Sciences, University of Alberta, Edmonton, AB T6G 2P5, Canada
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Moehn S, Rafii M, Pencharz PB, Ball RO. Protein turnover in pregnant pigs when feeding limiting amounts of amino acids. FASEB J 2013. [DOI: 10.1096/fasebj.27.1_supplement.1082.2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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Moehn S, Rafii M, Pencharz PB, Ball RO. Protein turnover in pregnant pigs at amino acid intake in excess of requirements. FASEB J 2013. [DOI: 10.1096/fasebj.27.1_supplement.345.8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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Rafii M, Courtney‐Martin G, Chapman K, Owens J, Elango R, Campbell WW, Ball RO, Pencharz PB. Dietary protein requirement of 65–75 year old females using indicator amino acid oxidation (IAAO) technique. FASEB J 2013. [DOI: 10.1096/fasebj.27.1_supplement.1075.6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Mahroukh Rafii
- Research InstituteThe Hospital for Sick ChildrenTorontoONCanada
| | | | - Karen Chapman
- Research InstituteThe Hospital for Sick ChildrenTorontoONCanada
| | - Jillian Owens
- Research InstituteThe Hospital for Sick ChildrenTorontoONCanada
| | - Rajavel Elango
- Department of PediatricsUniversity of British ColombiaVancouverBCCanada
| | | | - Ronald O Ball
- Department of Agriculture, Food and Nutritional ScienceUniversity of AlbertaEdmontonABCanada
| | - Paul B Pencharz
- Research InstituteThe Hospital for Sick ChildrenTorontoONCanada
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Josephson JK, Wales PW, Nation PN, Wizzard P, Mager D, Field CJ, Ball RO, Pencharz PB, Turner JM. Parenteral lipid minimization versus composition for intestinal failure associated liver disease. FASEB J 2013. [DOI: 10.1096/fasebj.27.1_supplement.1072.15] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
| | - Paul W Wales
- Pediatric SurgeryUniversity of TorontoTorontoABCanada
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Courtney‐Martin G, Rafii M, Chapman K, Elango R, Campbell WW, Ball RO, Pencharz PB. Dietary protein requirement of 65–75 year old adult males using indicator amino acid oxidation (IAAO) technique. FASEB J 2013. [DOI: 10.1096/fasebj.27.1_supplement.1075.12] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
| | - Mahroukh Rafii
- Research InstituteThe Hospital for Sick ChildrenTorontoONCanada
| | - Karen Chapman
- Research InstituteThe Hospital for Sick ChildrenTorontoONCanada
| | - Rajavel Elango
- Department of PediatricsBC Children's HospitalVancouverBCCanada
| | | | - Ronald O Ball
- Agriculture, Food and Nutritional ScienceUniversity of AlbertaEdmontonABCanada
| | - Paul B Pencharz
- Research InstituteThe Hospital for Sick ChildrenTorontoONCanada
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Chapman KP, Elango R, Ball RO, Pencharz PB. Splanchnic first pass disappearance of threonine and lysine do not differ in healthy men in the fed state. J Nutr 2013; 143:290-4. [PMID: 23325919 DOI: 10.3945/jn.112.168328] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
We previously showed that the splanchnic bed of neonates takes up a significantly higher amount (43%) of threonine in contrast to lysine (12%). We questioned whether this same pattern applied in adult humans and found no information in the literature. Therefore, our objective in the current study was to determine the difference in splanchnic first pass disappearance of threonine and lysine in adult humans during the fed state. During two 5-d study periods, 6 healthy men received l-[1-(13)C]threonine or l-[1-(13)C]lysine enterally or parenterally randomized to either study d 3 or 5, respectively. The diets were in the form of an amino acid mixture providing a protein intake of 1 g · kg(-1) · d(-1) and an energy intake of 1.5 times the resting energy expenditure. Blood and breath samples were collected at baseline and plateau for amino acid and 11CO(2) enrichment. Splanchnic disappearances in adult males were similar for threonine and lysine. The splanchnic disappearance of threonine as a percentage of intake was 17.9% (8.4 mg · kg(-1) · d(-1)) in the healthy men compared with 18.5% (11.2 mg · kg(-1) · d(-1)) for lysine. We conclude that the threonine requirement of the gut of healthy men consuming a liquid formula diet based on free amino acids is similar to the lysine requirement, which is in contrast to our previous findings for neonates.
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Affiliation(s)
- Karen P Chapman
- The Research Institute, The Hospital for Sick Children, Toronto, Canada
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Prolla IRD, Rafii M, Courtney-Martin G, Elango R, da Silva LP, Ball RO, Pencharz PB. Lysine from cooked white rice consumed by healthy young men is highly metabolically available when assessed using the indicator amino acid oxidation technique. J Nutr 2013; 143:302-6. [PMID: 23325920 DOI: 10.3945/jn.112.166728] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Cooked white rice (CWR) provides up to 71% of the dietary protein for many people worldwide. The protein digestibility-corrected amino acid (AA) score is the method adopted by FAO/WHO to evaluate protein quality. Our group has proposed the metabolic availability (MA) of AAs as another determinant of protein quality. It measures the percentage of an indispensable AA that is incorporated during protein synthesis. This study is the first to our knowledge to assess the MA of l-lysine (L-Lys) from CWR in humans using the indicator AA oxidation (IAAO) technique. Three amounts of L-Lys, 10, 15, and 19 mg · kg(-1) · d(-1) (= 28.5, 42.8, and 54.3% of the mean L-Lys requirement of 35 mg · kg(-1) · d(-1)), were studied in 5 healthy young men in a repeated-measures design. To test the principle that the Maillard reaction has an effect on the MA of LLys, we also assessed the MA of L-Lys in oven-browned, cooked rice (n = 3) in the amount of 19 mg · kg(-1) · d(-1) L-Lys. The MA of L-Lys was estimated by comparing the IAAO response with varying L-Lys intakes in rice compared with the IAAO response to varying l-Lys intakes in the reference protein (crystalline AA mixture patterned after egg protein) using the slope ratio method. The MA of L-Lys from CWR was high (97%), but the effect of the Maillard reaction reduced it to 70%. The results show that despite its relatively low content in rice, L-Lys has a high MA when the rice is cooked without being browned.
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Affiliation(s)
- Ivo R D Prolla
- Department of Pediatrics, Federal University of Santa Maria, Santa Maria, Rio Grande do Sul, Brazil
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Bertolo RF, Pencharz PB, Ball RO. Tissue Mineral Concentrations Are Profoundly Altered in Neonatal Piglets Fed Identical Diets via Gastric, Central Venous, or Portal Venous Routes. JPEN J Parenter Enteral Nutr 2013; 38:227-35. [DOI: 10.1177/0148607113478190] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Affiliation(s)
- Robert F. Bertolo
- Department of Biochemistry, Memorial University of Newfoundland, St John’s, Newfoundland and Labrador, Canada
| | - Paul B. Pencharz
- Department of Agricultural, Food and Nutritional Science, University of Alberta, Edmonton, Alberta, Canada
- The Research Institute, The Hospital for Sick Children, Toronto, Ontario, Canada
- Department of Nutritional Sciences, University of Toronto, Toronto, Ontario, Canada
| | - Ronald O. Ball
- Department of Agricultural, Food and Nutritional Science, University of Alberta, Edmonton, Alberta, Canada
- The Research Institute, The Hospital for Sick Children, Toronto, Ontario, Canada
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Moehn S, Pencharz PB, Ball RO. Lessons learned regarding symptoms of tryptophan deficiency and excess from animal requirement studies. J Nutr 2012; 142:2231S-2235S. [PMID: 23077198 DOI: 10.3945/jn.112.159061] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Tryptophan is the precursor for several neurotransmitters and metabolic regulators, which, although quantitatively of little importance in determining the dietary requirement, have major importance for interpreting symptoms of dietary tryptophan deficiency and excess. The quantitative dietary tryptophan requirement appears to vary widely across species, so intakes relative to requirements are more appropriate expressions for comparison of adverse effects across species than daily intake or diet concentration. Symptoms of tryptophan deficiency may occur at intakes as little as 25% below the requirement. Symptoms include reduced feed intake and reduced growth rate but also impaired skeletal development and aberrant behavior. Older animals appear less susceptible than younger animals to tryptophan deficiency and females less than males. Symptoms of excess tryptophan intake include reduced food intake and growth rate. In growing animals, it appears that tryptophan intakes of >10 times the requirement are necessary before there are detrimental effects on growth performance. At still greater intakes, fatty liver and fibrotic changes in muscles, lung, and pancreas and the serotonin syndrome may develop. In pigs, tryptophan intake of 60 times the daily requirement did not cause mortality. The maximal tryptophan oxidation rate, measured in vivo using (13)C universally labeled tryptophan, may be a possible marker of the intake above which increasing intake increases the risk of adverse effects. The advantage of the oxidation technique is that it does not necessarily rely on but still allows the identification and measurement of amino acid metabolites and is therefore simpler and more universally applicable.
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Affiliation(s)
- Soenke Moehn
- Department of Agriculture, Food and Nutritional Sciences, University of Alberta, Edmonton, Canada
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Abstract
Leucine is purported to improve athletic performance. Therefore, the BCAA, especially leucine, are popular as dietary supplements among strength-training athletes. There are, however, concerns regarding possible adverse effects of excessive leucine intake. The objective of the current study was to determine the metabolic and adverse effects of the acute ingestion of very high intakes of leucine supplements. Five healthy men (20-35 y) each received graded stepwise increases in leucine intakes of 50, 150, 250, 500, 750, 1000, and 1250 mg · kg(-1) · d(-1) corresponding to the Estimated Average Requirement, and Estimated Average Requirement ×3, ×5, ×10, ×15, ×20, and ×25 to a total of 29 studies. The graded stepwise approach was used rather than a randomization of leucine intake to minimize the possibility of severe adverse effects. Participants were given a maintenance diet for 2 d prior to each leucine level containing 1 g · kg(-1) · d(-1) of protein and 1.7× measured the resting metabolic rate. Leucine oxidation was determined using L-[1-13C]-leucine and the appearance of (13)CO(2) (calculated as F(13)CO(2)) in breath. A range of markers was used to monitor for adverse effects, including glucose, insulin, alanine aminotransferase, and ammonia. Plasma leucine concentrations significantly increased beyond an intake of 500 mg · kg(-1) · d(-1). The metabolic limit to oxidize leucine was between 550 and 700 mg · kg(-1) · d(-1). An increase in blood ammonia concentrations was observed at leucine intakes >500 mg · kg(-1) · d(-1). There were no changes in liver alanine aminotransferase. Glucose concentrations fell (P < 0.004) but remained within the normal range and without any change in insulin. This study is the first to our knowledge to directly estimate the safe upper limit of leucine intake in humans and raises concerns that intakes >550 mg · kg(-1) · d(-1) or ~39 g/d may be a risk to health. It is important to note that these are acute studies, where each participant was exposed to graded increases in leucine intake. Longer term adaptation was not studied.
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Affiliation(s)
- Paul B Pencharz
- The Research Institute, The Hospital for Sick Children, Toronto, ON, Canada.
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Ball RO. Protein requirements: time to re-evaluate Canadian recommendations. Can Nurse 2012; 108:5. [PMID: 23156007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Affiliation(s)
- Ronald O Ball
- Department of Agriculture, Food and Nutritional Sciences, University of Alberta
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Elango R, Chapman K, Rafii M, Ball RO, Pencharz PB. Determination of the tolerable upper intake level of leucine in acute dietary studies in young men. Am J Clin Nutr 2012; 96:759-67. [PMID: 22952178 DOI: 10.3945/ajcn.111.024471] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
BACKGROUND Leucine has been suggested to improve athletic performance. Therefore, the branched-chain amino acids (BCAAs), especially leucine, are popular as dietary supplements in strength-training athletes; however, the intake of leucine in excess of requirements raises concerns regarding adverse effects. Currently, the tolerable upper intake level (UL) for leucine is unknown. OBJECTIVE The objective of the current study was to determine the UL for leucine in adult men under acute dietary conditions. DESIGN Five healthy adults (20-35 y) each received graded stepwise increases in leucine intakes of 50, 150, 250, 500, 750, 1000, and 1250 mg · kg⁻¹ · d⁻¹, which corresponded to the Estimated Average Requirement (EAR) and the EAR ×3, ×5, ×10, ×15, ×20, and ×25 in a total of 29 studies. The UL of leucine was identified by the measurement of plasma and urinary biochemical variables and changes in leucine oxidation by using l-[1-¹³C]-leucine. RESULTS A significant increase in blood ammonia concentrations above normal values, plasma leucine concentrations, and urinary leucine excretion were observed with leucine intakes >500 mg · kg⁻¹ · d⁻¹. The oxidation of l-[1-¹³C]-leucine expressed as label tracer oxidation in breath (F¹³CO₂), leucine oxidation, and α-ketoisocaproic acid (KIC) oxidation led to different results: a plateau in F¹³CO₂ observed after 500 mg · kg⁻¹ · d⁻¹, no clear plateau observed in leucine oxidation, and KIC oxidation appearing to plateau after 750 mg · kg⁻¹ · d⁻¹. CONCLUSION On the basis of plasma and urinary variables, the UL for leucine in healthy adult men can be suggested at 500 mg · kg⁻¹ · d⁻¹ or ~35 g/d as a cautious estimate under acute dietary conditions.
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Affiliation(s)
- Rajavel Elango
- Research Institute, The Hospital for Sick Children, Toronto, Canada
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Tomlinson C, Rafii M, Kamaleswaran R, Ball RO, Pencharz PB. Fractional synthesis rate of creatine from arginine in healthy adult men. FASEB J 2012. [DOI: 10.1096/fasebj.26.1_supplement.1013.15] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Christopher Tomlinson
- Research InstituteThe Hospital for Sick ChildrenTorontoONCanada
- Department of Nutritional SciencesUniversity of TorontoTorontoONCanada
| | - Mahroukh Rafii
- Research InstituteThe Hospital for Sick ChildrenTorontoONCanada
| | | | - Ronald O. Ball
- Department of Nutritional SciencesUniversity of TorontoTorontoONCanada
- Department of AgricultureFood and Nutritional SciencesUniversity of AlbertaEdmontonABCanada
| | - Paul B. Pencharz
- Research InstituteThe Hospital for Sick ChildrenTorontoONCanada
- Department of AgricultureFood and Nutritional SciencesUniversity of AlbertaEdmontonABCanada
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Tang M, McCabe GP, Elango R, Pencharz PB, Ball RO, Campbell WW. Protein requirement of elderly women determined using the indicator amino acid oxidation technique. FASEB J 2012. [DOI: 10.1096/fasebj.26.1_supplement.42.5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Minghua Tang
- Department of Nutrition SciencePurdue UniversityWest LafayetteIN
| | | | - Rajavel Elango
- Department of PediatricsUniversity of British ColumbiaVancouverBCCanada
| | - Paul B Pencharz
- Department of Nutritional ScienceUniversity of TorontoTorontoONCanada
- Gastroenterology, Hepatology and NutritionThe Hospital for Sick ChildrenTorontoONCanada
| | - Ronald O Ball
- Department of Agriculrual, Food, and Nutritional ScienceUniversity of AlbertaEdmontonABCanada
| | - Wayne W Campbell
- Department of Nutrition SciencePurdue UniversityWest LafayetteIN
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