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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] [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] [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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Yang J, Zhou Y, Jiang Y. Amino Acids in Rice Grains and Their Regulation by Polyamines and Phytohormones. PLANTS (BASEL, SWITZERLAND) 2022; 11:1581. [PMID: 35736731 PMCID: PMC9228293 DOI: 10.3390/plants11121581] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/26/2022] [Revised: 06/10/2022] [Accepted: 06/13/2022] [Indexed: 06/15/2023]
Abstract
Rice is one of the most important food crops in the world, and amino acids in rice grains are major nutrition sources for the people in countries where rice is the staple food. Phytohormones and plant growth regulators play vital roles in regulating the biosynthesis of amino acids in plants. This paper reviewed the content and compositions of amino acids and their distribution in different parts of ripe rice grains, and the biosynthesis and metabolism of amino acids and their regulation by polyamines (PAs) and phytohormones in filling grains, with a focus on the roles of higher PAs (spermidine and spermine), ethylene, and brassinosteroids (BRs) in this regulation. Recent studies have shown that higher PAs and BRs (24-epibrassinolide and 28-homobrassinolide) play positive roles in mediating the biosynthesis of amino acids in rice grains, mainly by enhancing the activities of the enzymes involved in amino acid biosynthesis and sucrose-to-starch conversion and maintaining redox homeostasis. In contrast, ethylene may impede amino acid biosynthesis by inhibiting the activities of the enzymes involved in amino acid biosynthesis and elevating reactive oxygen species. Further research is needed to unravel the temporal and spatial distribution characteristics of the content and compositions of amino acids in the filling grain and their relationship with the content and compositions of amino acids in different parts of a ripe grain, to elucidate the cross-talk between or among phytohormones in mediating the anabolism of amino acids, and to establish the regulation techniques for promoting the biosynthesis of amino acids in rice grains.
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Kaidarova DR, Kopp MV, Pokrovsky VS, Dzhugashvili M, Akimzhanova ZM, Abdrakhmanov RZ, Babich EN, Bilan EV, Byakhov AV, Gurov SN, Koroleva IA, Mochalova AS, Povaga SS, Raigorodsky MV, Saifullin AS, Sanz E, Petrovskiy FI. Multicomponent nutritional supplement Oncoxin and its influence on quality of life and therapy toxicity in patients receiving adjuvant chemotherapy. Oncol Lett 2019; 18:5644-5652. [PMID: 31641390 PMCID: PMC6798186 DOI: 10.3892/ol.2019.10868] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2019] [Accepted: 07/11/2019] [Indexed: 12/25/2022] Open
Abstract
Treatment of cancer often requires the use of adjuvant chemotherapy (ACT). In real clinical practice, numerous patients suffer from severe toxicity and reduced quality of life (QoL). Hence, there is a need to maintain QoL and to reduce therapy toxicity to comply with recommended chemotherapy (CT) regimens. The present study focused on the effects of the multi-component nutritional supplement Oncoxin (ONCX) on QoL and CT-induced toxicity in patients undergoing ACT. A total of 133 patients aged 50-70 years with gastric cancer IIB-IIIC or non-small cell lung cancer IIB-IIIA were enrolled in the present study: 84 received ONCX, and 49 were included in the control arm and received CT only. It was identified that after 2 weeks of treatment the patients receiving ONCX exhibited clinically meaningful improvement of QoL (measured by Edmonton Symptom Assessment System Questionnaire) compared with those in the control group (odds ratio, 2.07; 95% CI, 1.00-4.29). By the end of a 3 week-period, the albumin level was higher in patients of the ONCX group compared with those in the control group (mean, 38.1; 95% CI, 37.1-39.1 g/l; vs. mean, 35.5; 95% CI, 33.9-37.0; P=0.03; respectively). Furthermore, the use of ONCX substantively reduced the hepatic toxicity of ACT. The present prospective real clinical setting study revealed positive effects of ONCX on QoL and ACT toxicity. The present study was retrospectively registered under the study registration number NCT03550482 at ClinicalTrials.gov (June 8, 2018).
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Affiliation(s)
| | | | - Vadim S Pokrovsky
- Department of Biochemistry, N.N. Blokhin Cancer Research Center, RUDN University, Moscow 115478, Russia
| | - Maia Dzhugashvili
- Department of Oncology Radiology, Murcia University, Murcia 30200, Spain
| | | | | | - Elena Nikolaevna Babich
- Department of Oncology, Khanty-Mansiysk Regional Clinical Hospital, Khanty-Mansiysk 628012, Russia
| | | | - Anton Valeryevich Byakhov
- Department of Chemotherapy, Moscow Clinical Scientific Center n. a. A.S. Loginov, Moscow 111123, Russia
| | | | | | | | - Svetlana Sergeevna Povaga
- Department of Chemotherapy, Russian Railways Hospital at The Station Smolensk, Smolensk 214025, Russia
| | | | | | - Eduardo Sanz
- Scientific Department, Catalysis S.L., Madrid 28016, Spain
| | - Fedor Igorevich Petrovskiy
- Department of Pharmacology and Clinical Pharmacology, Khanty-Mansiysk State Medical Academy, Khanty-Mansiysk 628011, Russia
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Le DT, Chu HD, Le NQ. Improving Nutritional Quality of Plant Proteins Through Genetic Engineering. Curr Genomics 2016; 17:220-9. [PMID: 27252589 PMCID: PMC4869009 DOI: 10.2174/1389202917666160202215934] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2015] [Revised: 05/23/2015] [Accepted: 06/01/2015] [Indexed: 11/22/2022] Open
Abstract
Humans and animals are unable to synthesize essential amino acids such as branch chain amino acids methionine (Met), lysine (Lys) and tryptophan (Trp). Therefore, these amino acids need to be supplied through the diets. Several essential amino acids are deficient or completely lacking among crops used for human food and animal feed. For example, soybean is deficient in Met; Lys and Trp are lacking in maize. In this mini review, we will first summarize the roles of essential amino acids in animal nutrition. Next, we will address the question: “What are the amino acids deficient in various plants and their biosynthesis pathways?” And: “What approaches are being used to improve the availability of essential amino acids in plants?” The potential targets for metabolic engineering will also be discussed, including what has already been done and what remains to be tested.
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Affiliation(s)
- Dung Tien Le
- National Key Laboratory of Plant and Cell Technology, Agricultural Genetics Institute, Vietnam Academy of Agricul-tural Science, Pham Van Dong Str., Hanoi, Vietnam
| | - Ha Duc Chu
- National Key Laboratory of Plant and Cell Technology, Agricultural Genetics Institute, Vietnam Academy of Agricul-tural Science, Pham Van Dong Str., Hanoi, Vietnam
| | - Ngoc Quynh Le
- National Key Laboratory of Plant and Cell Technology, Agricultural Genetics Institute, Vietnam Academy of Agricul-tural Science, Pham Van Dong Str., Hanoi, Vietnam
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Abstract
Hydrogen sulfide (H₂S) has emerged as an important signaling molecule with beneficial effects on various cellular processes affecting, for example, cardiovascular and neurological functions. The physiological importance of H₂S is motivating efforts to develop strategies for modulating its levels. However, advancement in the field of H₂S-based therapeutics is hampered by fundamental gaps in our knowledge of how H₂S is regulated, its mechanism of action, and its molecular targets. This review provides an overview of sulfur metabolism; describes recent progress that has shed light on the mechanism of H₂S as a signaling molecule; and examines nutritional regulation of sulfur metabolism, which pertains to health and disease.
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Affiliation(s)
- Omer Kabil
- Department of Biological Chemistry, University of Michigan Medical School, Ann Arbor, Michigan 48109-0600;
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Protein and amino acid supplementation in older humans. Amino Acids 2013; 44:1493-509. [DOI: 10.1007/s00726-013-1480-6] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2013] [Accepted: 02/21/2013] [Indexed: 01/09/2023]
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Current understanding of the factors regulating methionine content in vegetative tissues of higher plants. Amino Acids 2010; 39:917-31. [DOI: 10.1007/s00726-010-0482-x] [Citation(s) in RCA: 74] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2009] [Accepted: 01/12/2010] [Indexed: 01/14/2023]
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Effect of methionine dietary supplementation on mitochondrial oxygen radical generation and oxidative DNA damage in rat liver and heart. J Bioenerg Biomembr 2009; 41:309-21. [PMID: 19633937 DOI: 10.1007/s10863-009-9229-3] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2009] [Accepted: 06/17/2009] [Indexed: 10/20/2022]
Abstract
Methionine restriction without energy restriction increases, like caloric restriction, maximum longevity in rodents. Previous studies have shown that methionine restriction strongly decreases mitochondrial reactive oxygen species (ROS) production and oxidative damage to mitochondrial DNA, lowers membrane unsaturation, and decreases five different markers of protein oxidation in rat heart and liver mitochondria. It is unknown whether methionine supplementation in the diet can induce opposite changes, which is also interesting because excessive dietary methionine is hepatotoxic and induces cardiovascular alterations. Because the detailed mechanisms of methionine-related hepatotoxicity and cardiovascular toxicity are poorly understood and today many Western human populations consume levels of dietary protein (and thus, methionine) 2-3.3 fold higher than the average adult requirement, in the present experiment we analyze the effect of a methionine supplemented diet on mitochondrial ROS production and oxidative damage in the rat liver and heart mitochondria. In this investigation male Wistar rats were fed either a L-methionine-supplemented (2.5 g/100 g) diet without changing any other dietary components or a control (0.86 g/100 g) diet for 7 weeks. It was found that methionine supplementation increased mitochondrial ROS generation and percent free radical leak in rat liver mitochondria but not in rat heart. In agreement with these data oxidative damage to mitochondrial DNA increased only in rat liver, but no changes were observed in five different markers of protein oxidation in both organs. The content of mitochondrial respiratory chain complexes and AIF (apoptosis inducing factor) did not change after the dietary supplementation while fatty acid unsaturation decreased. Methionine, S-AdenosylMethionine and S-AdenosylHomocysteine concentration increased in both organs in the supplemented group. These results show that methionine supplementation in the diet specifically increases mitochondrial ROS production and mitochondrial DNA oxidative damage in rat liver mitochondria offering a plausible mechanism for its hepatotoxicity.
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Blanco RA, Ziegler TR, Carlson BA, Cheng PY, Park Y, Cotsonis GA, Accardi CJ, Jones DP. Diurnal variation in glutathione and cysteine redox states in human plasma. Am J Clin Nutr 2007; 86:1016-23. [PMID: 17921379 DOI: 10.1093/ajcn/86.4.1016] [Citation(s) in RCA: 143] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
BACKGROUND Plasma glutathione/glutathione disulfide (GSH/GSSG) and cysteine/cystine (Cys/CySS) couples are oxidized in humans in association with oxidative stress and cardiovascular disease risk. Animal studies show that both pools undergo diurnal variations associated with dietary intake of sulfur amino acids. OBJECTIVE The objective of this study was to determine whether the redox state of GSH, Cys, GSH/GSSG, or Cys/CySS undergoes diurnal variation in healthy adults. DESIGN Plasma samples were collected every hour for 24 h from 63 persons aged 18-86 y who were consuming normal food (protein, 0.8 g kg(-1) d(-1); sulfur amino acids, 20 mg kg(-1) d(-1)) at standardized mealtimes. Measurements of Cys, CySS, GSH, and GSSG were used with the Nernst equation to calculate the redox states. RESULTS Plasma Cys and GSH concentrations varied with the time of day. The highest values for plasma Cys occurred approximately 3 h after meals. Glutathione was maximal 6 h after peak plasma Cys. The calculated redox states of the GSH/GSSG and Cys/CySS couples varied in association with the concentrations of the thiol forms. Maximal reduction and oxidation of the Cys/CySS couple occurred at 2130 and 0630, whereas the respective values for the GSH/GSSG couple occurred at 0330 and 1330. The mean diurnal variation for Cys/CySS redox in persons aged >or=60 y was 1.8-fold that in persons aged <40 y. CONCLUSIONS Cys/CySS and GSH/GSSG redox states in human plasma undergo diurnal variation with an increased magnitude of variation in Cys/CySS redox state in older persons. This variation could alter sensitivity to oxidative stress over a course of hours.
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Affiliation(s)
- Roberto A Blanco
- Division of Endocrinology, Metabolism and Lipids, Department of Medicine, Emory University, Atlanta, GA 30322, USA
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Ott N, Geddert H, Sarbia M. Polymorphisms in methionine synthase (A2756G) and cystathionine beta-synthase (844ins68) and susceptibility to carcinomas of the upper gastrointestinal tract. J Cancer Res Clin Oncol 2007; 134:405-10. [PMID: 17726616 DOI: 10.1007/s00432-007-0301-2] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2006] [Accepted: 08/14/2007] [Indexed: 12/30/2022]
Abstract
PURPOSE Folate deficiency is considered to increase the risk for the development of malignant tumors such as prostate and colorectal cancer. Methionine synthase (MTR) and cystathionine ss-synthase (CBS) are enzymes that play a central role in folate metabolism, thereby affecting DNA methylation and synthesis. A single A-->G substitution at nucleotide 2756 of the MTR and a 68 bp CBS insertion polymorphism in exon 8 have been associated with decreased enzyme activity. The purpose of this study is to compare the association of the MTR A2756G polymorphism and CBS insertion polymorphism with susceptibility to carcinomas of the upper gastrointestinal tract. METHODS Using the restriction fragment length polymorphism (RFLP)-PCR, the prevalence of MTR A2756G and CBS insertion polymorphism was determined in healthy controls (n = 257) and in patients with esophageal squamous cell carcinoma (ESCC) (n = 263), Barrett's esophagus-associated esophageal adenocarcinoma (BC) (n = 89), cardiac carcinoma (CC) (n = 144), or gastric carcinoma (GC) (n = 221) from German Caucasian subjects. RESULTS No significant difference in MTR A2756G genotype distribution was observed between controls (A/A 66.9%, A/G 29.8%, G/G 3.3%) and patients with ESCC (A/A 61.7%, A/G 36.3%, G/G 2.1%), BC (A/A 69.2%, A/G 26.9%, G/G 3.9%), CC (A/A 51.8%, A/G 44.6%, G/G 3.6%), or GC (A/A 73.4%, A/G 20.9%, G/G 5.7%). Similarly, the CBS genotype (I: allele with 68 bp insertion; N: allele without insertion) distribution among German patients with ESCC (N/N 86.8%, I/N 13.2%), BC (N/N 90.2%, I/N 9.8%), CC (N/N 90.1%, I/N 9.9%) or GC (N/N 91.3%, I/N 8.7%) was not different from healthy controls (N/N 90.4%, I/N 9.6%). The gene allele constellation I/I was not present. CONCLUSIONS The current study suggests that there is no association between MTR A2756G polymorphism and the CBS (844ins68) insertion polymorphism and cancer of the upper gastrointestinal tract.
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Affiliation(s)
- N Ott
- Department of Pathology, Unfallkrankenhaus Berlin, Warener Strasse 7, 12683 Berlin, Germany
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van de Poll MCG, Dejong CHC, Soeters PB. Adequate range for sulfur-containing amino acids and biomarkers for their excess: lessons from enteral and parenteral nutrition. J Nutr 2006; 136:1694S-1700S. [PMID: 16702341 DOI: 10.1093/jn/136.6.1694s] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
The adequacy range of dietary requirements of specific amino acids in disease states is difficult to determine. In health, several techniques are available allowing rather precise quantification of requirements based on growth of the organism, rises in plasma concentration, or increases in the oxidation of marker amino acids during incremental administration of the amino acid under study. Requirements may not be similar in disease with regard to protein synthesis or with regard to specific functions such as scavenging of reactive oxygen species by compounds including glutathione. Requirements for this purpose can be assessed only when such a function can be measured and related to clinical outcome. There is apparent consensus concerning normal sulfur amino acid (SAA) requirements. WHO recommendations amount to 13 mg/kg per 24 h in healthy adults. This amount is roughly doubled in artificial nutrition regimens. In disease or after trauma, requirements may be altered for methionine, cysteine, and taurine. Although in specific cases of congenital enzyme deficiency, prematurity, or diminished liver function, hypermethionemia or hyperhomocysteinemia may occur, SAA supplementation can be considered safe in amounts exceeding 2-3 times the minimal recommended daily intake. Apart from some very specific indications (e.g., acetaminophen poisoning), the usefulness of SAA supplementation is not yet established. There is a growing body of data pointing out the potential importance of oxidative stress and resulting changes in redox state in numerous diseases including sepsis, chronic inflammation, cancer, AIDS/HIV, and aging. These observations warrant continued attention for the potential role of SAA supplementation. In particular, N-acetylcysteine remains promising for these conditions.
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Affiliation(s)
- Marcel C G van de Poll
- Department of Surgery, University Hospital Maastricht and Nutrition and Toxicology Research Institute Maastricht (NUTRIM), University Maastricht, Maastricht, the Netherlands
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Fukagawa NK. Sparing of methionine requirements: evaluation of human data takes sulfur amino acids beyond protein. J Nutr 2006; 136:1676S-1681S. [PMID: 16702339 DOI: 10.1093/jn/136.6.1676s] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
The intimate relation between amino acids and protein and nitrogen requirements is well recognized. Nutrition research has focused on the capacity of food to meet the need for nitrogen and indispensable amino acids (IAA) and led to the conclusion that the quality, not just the quantity, of protein is critical. This is especially relevant in regard to the sulfur amino acids (SAA) methionine and cysteine because of the increased understanding of their relation to chronic diseases (e.g., cardiovascular disease, dementia, cirrhosis), immunomodulation, DNA transcription, and RNA translation. Considerable effort has been expended to determine whether and to what extent cysteine can spare the requirement for the IAA methionine. In vivo studies in humans generally concur that the dietary requirement of the SAA ranges between 13 and 16 mg.kg(-1).d(-1), but how much can be met by cysteine relative to methionine remains controversial. This review examines the current status of in vivo estimates of methionine and cysteine requirements in human adults and considers needs beyond what is necessary for protein synthesis. Factors influencing the utilization of methionine and cysteine, especially those conditions that lead to toxicity on the one hand or beneficial effects on the other, are discussed. Data on alternative dietary sources of methyl groups (e.g., betaine, choline, phosphatidylcholine, S-adenosylmethionine, S-methylmethionine) or sulfur (e.g., N-acetylcysteine or L-2-oxothiazolidine-4-carboxylic acid) support a role for the SAA "beyond protein." Other pathways may influence the specific requirement for methionine and/or cysteine, especially when the person is challenged by disease, inadequate availability of food, or environmental stress.
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Affiliation(s)
- Naomi K Fukagawa
- Department of Medicine and General Clinical Research Center, University of Vermont College of Medicine, Burlington, Vermont 05405, USA.
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Hiraku Y, Murata M, Kawanishi S. Role of Oxidative DNA Damage in Dietary Carcinogenesis. Genes Environ 2006. [DOI: 10.3123/jemsge.28.127] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
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Rousseau AS, Robin S, Roussel AM, Ducros V, Margaritis I. Plasma homocysteine is related to folate intake but not training status. Nutr Metab Cardiovasc Dis 2005; 15:125-133. [PMID: 15871861 DOI: 10.1016/j.numecd.2005.02.002] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/17/2004] [Accepted: 02/11/2005] [Indexed: 11/17/2022]
Abstract
BACKGROUND AND AIM Lifestyle including intakes of several essential nutrients and physical activity are of particular interest in reducing plasma total homocysteine concentration (tHcy), a risk factor for cardiovascular diseases. The aim of this study was to determine in athletes, whether dietary factors such as intakes of folate, vitamin B6 and B12 were associated with lower plasma tHcy, and whether this depended on daily energy expenditure (EE) and type of physical activity performed (aerobic, anaerobic, intermittent). METHODS Seventy-four well-trained athletes completed 7-day food and activity records in a cross-sectional study. Blood was sampled on day 8. RESULTS Percentage of vegetal protein, vitamin B6, and folate intakes were higher and tHcy was lower (1) in athletes with high EE (> 16.72 MJ/d) compared to athletes with lower EE; (2) in aerobic athletes compared to intermittent athletes and sedentary subjects. After backward step by step analysis, folate intake was the only significant variable retained in the model to explain tHcy variability. Moreover, after introducing folate intake as a covariate in ANOVA tests, group effects on tHcy were no longer significant. Nutrient density of folate was inversely correlated to tHcy in athletes (r = -0.33; P = 0.004). CONCLUSION High energy intake (> 16.72 MJ/d) allows the necessary folate intake (> 500 microg/d) for tHcy decrease to occur, which is moreover favored by aerobic activity. The mechanism underlying low tHcy in relation to high EE could only play a minor role when compared to the effect of dietary folate intake on tHcy.
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Affiliation(s)
- A S Rousseau
- Laboratoire Nutrition, Vieillissement et Maladies Cardiovasculaires, UFR Pharmacie, UJF Grenoble, France
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