scholarly journals A Whole-Grain Diet Increases Whole-Body Protein Balance Compared to a Macronutrient-Matched Refined-Grain Diet

2021 ◽  
Author(s):  
Jacob T Mey ◽  
Jean-Philippe Godin ◽  
Amanda R Scelsi ◽  
Emily L Kullman ◽  
Steven K Malin ◽  
...  
Keyword(s):  
Older Adults ◽  
Protein Synthesis ◽  
Protein Turnover ◽  
Muscle Function ◽  
Whole Grains ◽  
Whole Body ◽  
Whole Grain ◽  
Protein Balance ◽  
Body Protein

Abstract Background There are limited data from randomized control trials to support or refute the contention that whole-grains may enhance protein metabolism in humans. The objectives were threefold: 1) to examine the clinical effects of a whole-grain diet on whole-body protein turnover; 2) the cellular effects of whole-grains on protein synthesis in skeletal muscle cells; and 3) the population effects of whole-grain intake on age-related muscle loss. Methods Adults with overweight/obesity (N = 14, age: 40±7 years, BMI: 33±5 kg/m2) were recruited into a crossover, randomized controlled trial (NCT01411540) in which isocaloric, macronutrient-matched whole-grain and refined-grain diets were fully provisioned for two 8-week periods. Diets differed only in the presence of whole-grains (50 g/1000 kcal). Whole-body protein kinetics were assessed at baseline and after each diet in the fasted-state (13C-Leucine) and integrated over 24-hours (15N-Glycine). In vitro studies utilizing C2C12 cells assessed global protein synthesis by SUnSET and anabolic signaling by Western blot. Complementary epidemiologic assessments using the NHANES database assessed the effect of whole-grain intake on muscle function assessed by gait speed in older adults (N = 2,783). Results Integrated 24-hour net protein balance was 3-fold higher on a whole-grain compared to a refined-grain diet (P = 0.04). A whole-grain wheat extract increased submaximal rates of global protein synthesis (27%, P<0.05) in vitro. In a large sample of older adults, whole-grain intake was associated with greater muscle function in older adults (OR (CI) = 0.92 (0.86, 0.98)). Conclusions Consuming 50 g/1000 kcal of whole-grains per day promotes greater whole-body protein turnover and enhances net protein balance in adults. Whole-grains impact skeletal muscle at the cellular level, and in older adults, associate with greater muscle function. Collectively, these data point to a new mechanism whereby whole-grain consumption favorably enhances protein turnover and improves health outcomes.

scholarly journals A Whole-Grain Diet Improves Whole-Body Protein Turnover Compared to a Macronutrient-Matched Refined-Grain Diet in Adults with Overweight/Obesity

2020 ◽  
Vol 4 (Supplement_2) ◽  
pp. 1661-1661
Author(s):  
Jacob Mey ◽  
John Kirwan
Keyword(s):  
Protein Synthesis ◽  
Protein Metabolism ◽  
Protein Turnover ◽  
Whole Grains ◽  
Whole Body ◽  
Protein Breakdown ◽  
Whole Grain ◽  
Protein Kinetics ◽  
Body Protein ◽  
Fasted State

Abstract Objectives We investigated the effect of consuming a whole-grain diet on whole-body protein metabolism compared to a macronutrient-matched refined-grain diet in adults with overweight/obesity using labelled amino acids (ClinicalTrials.gov Identifier: NCT01411540). Methods We conducted a randomized, controlled crossover trial in 14 adults with overweight/obesity (age: 40 ± 7 yrs, BMI: 33 ± 5 kg/m2) in which isocaloric, macronutrient-matched whole-grain (WG) and refined-grain (RG) diets were fully provided for two 8-week periods (with a 10-week washout period). Diets differed only in the inclusion of whole grains (50 g/1000 kcal). Body composition was measured via DEXA. Whole-body protein kinetics were assessed before and after each diet in the fasted state (13C-Leucine, primed, constant infusion) and over 24 hours (15N-Glycine, bolus). Protein kinetics were normalized to fat-free mass (FFM). Results Both diets resulted in mild weight loss (WG: −2.0 ± 2.5 kg; RG: −2.9 ± 3.3 kg; both P = 0.01 compared to baseline). Fasted-state leucine kinetics revealed greater protein synthesis (WG: 205 ± 61 µmol/kgFFM/hr; RG: 178 ± 36 µmol/kgFFM/hr; P = 0.04) and protein breakdown (WG: 235 ± 68 µmol/kgFFM/hr; RG: 203 ± 40 µmol/kgFFM/hr, P = 0.03) on a WG vs RG diet. This resulted in a more negative fasted-state net balance on a WG diet (WG: −30 ± 8 µmol/kg/hr; RG: −25 ± 6 µmol/kg/hr, P = 0.02). In contrast, 24-hour whole-body protein turnover measured by the end-product method (15N-Glycine), revealed greater protein synthesis (WG: 316 ± 135 mg protein/kgFFM/hr; RG: 250 ± 94 mg protein/kgFFM/hr) with no difference in protein breakdown, yielding a more positive 24-hr net balance on a WG diet (WG: 31 ± 21 mg protein/kgFFM/hr; RG: 10 ± 34 mg protein/kgFFM/hr). Conclusions A whole-grain diet increases whole-body leucine flux and results in a greater 24-hr net protein balance in adults with overweight/obesity compared to a refined-grain diet. This trial suggests whole-grains have an independent effect on protein metabolism and may benefit adults with overweight/obesity. Funding Sources This research was supported by the NIH (UL1 RR024989, T32DK007319 (JPK); T32AT004094 (JTM – trainee)) and an investigator-initiated grant from Nestle (JPK). Nestle Product Technology Center and Cereal Partners Worldwide provided the study meals and foods.

Chloroquine reduces whole body proteolysis in humans

1994 ◽  
Vol 267 (1) ◽  
pp. E183-E186 ◽  
Author(s):  
P. De Feo ◽  
E. Volpi ◽  
P. Lucidi ◽  
G. Cruciani ◽  
F. Santeusanio ◽  
...  
Keyword(s):  
Protein Synthesis ◽  
Protein Turnover ◽  
Plasma Concentrations ◽  
Whole Body ◽  
Body Protein ◽  
Leucine Kinetics ◽  
Lysosomal Proteolysis ◽  
Therapeutic Doses

The antimalaric drug chloroquine is a well known inhibitor of lysosomal proteolysis in vitro. The present study tests the hypothesis that therapeutic doses of the drug decrease proteolysis also in vivo in humans. Leucine kinetics were determined in 20 healthy volunteers given 12 and 1.5 h before the studies 250 and 500 mg, respectively, of chloroquine phosphate (n = 10) or similar tablets of placebo (n = 10). Chloroquine reduced the rates of leucine appearance, a measure of whole body proteolysis, from 2.45 +/- 0.08 to 2.19 +/- 0.08 mumol.kg-1.min-1 (P = 0.038) and those of nonoxidative leucine disposal, an estimate of whole body protein synthesis, from 2.16 +/- 0.08 to 1.95 +/- 0.06 mumol.kg-1.min-1 (P = 0.050). The drug resulted also in a marginally significant (P = 0.051) decrement in the plasma concentrations of glucose. The effects of chloroquine on protein turnover might be potentially useful in counteracting protein wasting complicating several catabolic diseases, whereas those on glucose metabolism can explain the sporadic occurrence of severe hypoglycemic episodes in malaria patients chronically treated with this drug.

Effect of glycogen availability on human skeletal muscle protein turnover during exercise and recovery

2010 ◽  
Vol 109 (2) ◽  
pp. 431-438 ◽  
Author(s):  
Krista R. Howarth ◽  
Stuart M. Phillips ◽  
Maureen J. MacDonald ◽  
Douglas Richards ◽  
Natalie A. Moreau ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Protein Synthesis ◽  
Protein Turnover ◽  
Muscle Protein ◽  
Whole Body ◽  
Skeletal Muscle Protein ◽  
Protein Balance ◽  
Body Protein ◽  
Muscle Protein Turnover ◽  
Net Protein

We examined the effect of carbohydrate (CHO) availability on whole body and skeletal muscle protein utilization at rest, during exercise, and during recovery in humans. Six men cycled at ∼75% peak O2 uptake (V̇o2peak) to exhaustion to reduce body CHO stores and then consumed either a high-CHO (H-CHO; 71 ± 3% CHO) or low-CHO (L-CHO; 11 ± 1% CHO) diet for 2 days before the trial in random order. After each dietary intervention, subjects received a primed constant infusion of [1-13C]leucine and l-[ring-2H5]phenylalanine for measurements of the whole body net protein balance and skeletal muscle protein turnover. Muscle, breath, and arterial and venous blood samples were obtained at rest, during 2 h of two-legged kicking exercise at ∼45% of kicking V̇o2peak, and during 1 h of recovery. Biopsy samples confirmed that the muscle glycogen concentration was lower in the L-CHO group versus the H-CHO group at rest, after exercise, and after recovery. The net leg protein balance was decreased in the L-CHO group compared with at rest and compared with the H-CHO condition, which was primarily due to an increase in protein degradation (area under the curve of the phenylalanine rate of appearance: 1,331 ± 162 μmol in the L-CHO group vs. 786 ± 51 μmol in the H-CHO group, P < 0.05) but also due to a decrease in protein synthesis late in exercise. There were no changes during exercise in the rate of appearance compared with rest in the H-CHO group. Whole body leucine oxidation increased above rest in the L-CHO group only and was higher than in the H-CHO group. The whole body net protein balance was reduced in the L-CHO group, largely due to a decrease in whole body protein synthesis. These data extend previous findings by others and demonstrate, using contemporary stable isotope methodology, that CHO availability influences the rates of skeletal muscle and whole body protein synthesis, degradation, and net balance during prolonged exercise in humans.

Measurement of protein turnover in the small intestine of lambs. 2. Effects of feed intake

1997 ◽  
Vol 128 (2) ◽  
pp. 233-246 ◽  
Author(s):  
S. A. NEUTZE ◽  
J. M. GOODEN ◽  
V. H. ODDY
Keyword(s):  
Amino Acids ◽  
Protein Synthesis ◽  
Small Intestine ◽  
Experimental Model ◽  
Feed Intake ◽  
Protein Turnover ◽  
Jugular Vein ◽  
Specific Radioactivity ◽  
Whole Body ◽  
Body Protein

This study used an experimental model, described in a companion paper, to examine the effects of feed intake on protein turnover in the small intestine of lambs. Ten male castrate lambs (∼ 10 months old) were offered, via continuous feeders, either 400 (n = 5) or 1200 (n = 5) g/day lucerne chaff, and mean experimental liveweights were 28 and 33 kg respectively. All lambs were prepared with catheters in the cranial mesenteric vein (CMV), femoral artery (FA), jugular vein and abomasum, and a blood flow probe around the CMV. Cr-EDTA (0·139 mg Cr/ml, ∼ 0·2 ml/min) was infused abomasally for 24 h and L-[2,6-3H]phenylalanine (Phe) (420±9·35 μCi into the abomasum) and L-[U-14C]phenylalanine (49·6±3·59 μCi into the jugular vein) were also infused during the last 8 h. Blood from the CMV and FA was sampled during the isotope infusions. At the end of infusions, lambs were killed and tissue (n = 4) and digesta (n = 2) samples removed from the small intestine (SI) of each animal. Transfers of labelled and unlabelled Phe were measured between SI tissue, its lumen and blood, enabling both fractional and absolute rates of protein synthesis and gain to be estimated.Total SI mass increased significantly with feed intake (P < 0·05), although not on a liveweight basis. Fractional rates of protein gain in the SI tended to increase (P = 0·12) with feed intake; these rates were −16·2 (±13·7) and 23·3 (±15·2) % per day in lambs offered 400 and 1200 g/day respectively. Mean protein synthesis and fractional synthesis rates (FSR), calculated from the mean retention of 14C and 3H in SI tissue, were both positively affected by feed intake (0·01 < P < 0·05). The choice of free Phe pool for estimating precursor specific radioactivity (SRA) for protein synthesis had a major effect on FSR. Assuming that tissue free Phe SRA represented precursor SRA, mean FSR were 81 (±15) and 145 (±24) % per day in lambs offered 400 and 1200 g/day respectively. Corresponding estimates for free Phe SRA in the FA and CMV were 28 (±2·9) and 42 (±3·5) % per day on 400 g/day, and 61 (±2·9) and 94 (±6·0) on 1200 g/day. The correct value for protein synthesis was therefore in doubt, although indirect evidence suggested that blood SRA (either FA or CMV) may be closest to true precursor SRA. This evidence included (i) comparison with flooding dose estimates of FSR, (ii) comparison of 3H[ratio ]14C Phe SRA in free Phe pools with this ratio in SI protein, and (iii) the proportion of SI energy use associated with protein synthesis.Using the experimental model, the proportion of small intestinal protein synthesis exported was estimated as 0·13–0·27 (depending on the choice of precursor) and was unaffected by feed intake. The contribution of the small intestine to whole body protein synthesis tended to be higher in lambs offered 1200 g/day (0·21) than in those offered 400 g/day (0·13). The data obtained in this study suggested a role for the small intestine in modulating amino acid supply with changes in feed intake. At high intake (1200 g/day), the small intestine increases in mass and CMV uptake of amino acids is less than absorption from the lumen, while at low intake (400 g/day), this organ loses mass and CMV uptake of amino acids exceeds that absorbed. The implications of these findings are discussed.

Combined ingestion of protein and free leucine with carbohydrate increases postexercise muscle protein synthesis in vivo in male subjects

2005 ◽  
Vol 288 (4) ◽  
pp. E645-E653 ◽  
Author(s):  
René Koopman ◽  
Anton J. M. Wagenmakers ◽  
Ralph J. F. Manders ◽  
Antoine H. G. Zorenc ◽  
Joan M. G. Senden ◽  
...  
Keyword(s):  
Protein Synthesis ◽  
Muscle Protein ◽  
Muscle Protein Synthesis ◽  
Whole Body ◽  
Vastus Lateralis Muscle ◽  
Protein Balance ◽  
Body Protein ◽  
Breakdown Rates ◽  
Postexercise Recovery ◽  
Male Subjects

The present study was designed to determine postexercise muscle protein synthesis and whole body protein balance following the combined ingestion of carbohydrate with or without protein and/or free leucine. Eight male subjects were randomly assigned to three trials in which they consumed drinks containing either carbohydrate (CHO), carbohydrate and protein (CHO+PRO), or carbohydrate, protein, and free leucine (CHO+PRO+Leu) following 45 min of resistance exercise. A primed, continuous infusion of l-[ ring-13C6]phenylalanine was applied, with blood samples and muscle biopsies collected to assess fractional synthetic rate (FSR) in the vastus lateralis muscle as well as whole body protein turnover during 6 h of postexercise recovery. Plasma insulin response was higher in the CHO+PRO+Leu compared with the CHO and CHO+PRO trials (+240 ± 19% and +77 ± 11%, respectively, P < 0.05). Whole body protein breakdown rates were lower, and whole body protein synthesis rates were higher, in the CHO+PRO and CHO+PRO+Leu trials compared with the CHO trial ( P < 0.05). Addition of leucine in the CHO+PRO+Leu trial resulted in a lower protein oxidation rate compared with the CHO+PRO trial. Protein balance was negative during recovery in the CHO trial but positive in the CHO+PRO and CHO+PRO+Leu trials. In the CHO+PRO+Leu trial, whole body net protein balance was significantly greater compared with values observed in the CHO+PRO and CHO trials ( P < 0.05). Mixed muscle FSR, measured over a 6-h period of postexercise recovery, was significantly greater in the CHO+PRO+Leu trial compared with the CHO trial (0.095 ± 0.006 vs. 0.061 ± 0.008%/h, respectively, P < 0.05), with intermediate values observed in the CHO+PRO trial (0.0820 ± 0.0104%/h). We conclude that coingestion of protein and leucine stimulates muscle protein synthesis and optimizes whole body protein balance compared with the intake of carbohydrate only.

scholarly journals Muscle Protein Synthesis and Whole-Body Protein Turnover Responses to Ingesting Essential Amino Acids, Intact Protein, and Protein-Containing Mixed Meals with Considerations for Energy Deficit

Nutrients ◽  
2020 ◽  
Vol 12 (8) ◽  
pp. 2457 ◽  
Author(s):  
Jess A. Gwin ◽  
David D. Church ◽  
Robert R. Wolfe ◽  
Arny A. Ferrando ◽  
Stefan M. Pasiakos
Keyword(s):  
Amino Acids ◽  
Protein Synthesis ◽  
Protein Turnover ◽  
Muscle Protein ◽  
Muscle Protein Synthesis ◽  
Energy Deficit ◽  
Whole Body ◽  
Intact Protein ◽  
Body Protein ◽  
Protein Feeding

Protein intake recommendations to optimally stimulate muscle protein synthesis (MPS) are derived from dose-response studies examining the stimulatory effects of isolated intact proteins (e.g., whey, egg) on MPS in healthy individuals during energy balance. Those recommendations may not be adequate during periods of physiological stress, specifically the catabolic stress induced by energy deficit. Providing supplemental intact protein (20–25 g whey protein, 0.25–0.3 g protein/kg per meal) during strenuous military operations that elicit severe energy deficit does not stimulate MPS-associated anabolic signaling or attenuate lean mass loss. This occurs likely because a greater proportion of the dietary amino acids consumed are targeted for energy-yielding pathways, whole-body protein synthesis, and other whole-body essential amino acid (EAA)-requiring processes than the proportion targeted for MPS. Protein feeding formats that provide sufficient energy to offset whole-body energy and protein-requiring demands during energy deficit and leverage EAA content, digestion, and absorption kinetics may optimize MPS under these conditions. Understanding the effects of protein feeding format-driven alterations in EAA availability and subsequent changes in MPS and whole-body protein turnover is required to design feeding strategies that mitigate the catabolic effects of energy deficit. In this manuscript, we review the effects, advantages, disadvantages, and knowledge gaps pertaining to supplemental free-form EAA, intact protein, and protein-containing mixed meal ingestion on MPS. We discuss the fundamental role of whole-body protein balance and highlight the importance of comprehensively assessing whole-body and muscle protein kinetics when evaluating the anabolic potential of varying protein feeding formats during energy deficit.

scholarly journals The influence of rumen volatile fatty acids on protein metabolism in growing lambs

1989 ◽  
Vol 62 (2) ◽  
pp. 297-310 ◽  
Author(s):  
H. A. Abdul–Razzaq ◽  
R. Bickerstaffe
Keyword(s):  
Amino Acids ◽  
Protein Synthesis ◽  
Protein Turnover ◽  
Turnover Rate ◽  
Volatile Fatty Acids ◽  
Acid Group ◽  
High Plasma ◽  
Whole Body ◽  
Body Protein ◽  
Tyrosine Oxidation

The effect of acetic or propionic acid rumen fermentation patterns on whole-body protein turnover, tissue protein synthetic rates and body composition was investigated in growing lambs. Protein turnover was assessed using a continuous intravenous infusion of [2,3-3H]tyrosine and tissue protein fractional synthetic rates (FSR) from the specific activities of plasma free, intracellular free and tissue bound tyrosine. Only the FSR of muscle tissue approached significance. The high FSR in the propionic group was attributed to the high plasma insulin concentration. Values for whole-body protein synthesis, corrected for tyrosine oxidation, were similar to those obtained by summating protein synthesis in individual tissues, confirming that tyrosine oxidation should be measured accurately if reliable whole-body protein synthesis values are required. Tyrosine oxidation and flux were high in the acetic acid group, suggesting that amino acids are used for gluconeogenesis. The high protein turnover rate probably ensures an adequate supply of gluconeogenic amino acids and that the penalty of mobilizing body proteins for gluconeogenic amino acids is minimal. In the propionic acid group, high plasma glucose and insulin concentrations were associated with a low protein turnover rate, high ratio of deposited: synthesized protein and a high body fat content. It is concluded that changing the proportion of ruminal volatile fatty acids influences protein turnover, protein synthesis and the efficiency of protein retention. Such factors probably contribute, indirectly, to the observed differences in body composition.

scholarly journals The end-product method of measuring whole-body protein turnover: a review of published results and a comparison with those obtained by leucine infusion

2005 ◽  
Vol 94 (2) ◽  
pp. 141-153 ◽  
Author(s):  
S. L. Duggleby ◽  
J. C. Waterlow
Keyword(s):  
Protein Synthesis ◽  
Gold Standard ◽  
Protein Turnover ◽  
Population Studies ◽  
Whole Body ◽  
Precursor Method ◽  
Body Protein ◽  
Short Account ◽  
Product Method ◽  
Pros And Cons

The present review summarizes the results of all published papers on whole-body protein turnover in man measured by [15N]glycine and the end-product method using both urea and ammonia. It begins with a short account of the underlying assumptions and the justification for the use of [15N]glycine. The results are then compared with those of a large sample of measurements by the ‘gold standard’ precursor method with continuous infusion of [13C]leucine. The pros and cons of the two methods are compared and it is suggested that there is a place for further work by the less invasive end-product method, particularly for population studies of the genetic, environmental and functional determinants of whole-body rates of protein synthesis.

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