Studies on rate of protein synthesis

[OllieSA]

Hi all,

I am looking for info on the effect on protein synthesis for hypertrophy according to protein type (i.e. solids/casein/whey).

I am trying to determine what will work best for bed-time nutrition but I am unsure of a number of things, being a layman. With that in mind, please forgive my ignorance or misuse of terms.

I keep hearing about whey's fast rate of absorption, in contrast to casein's slow rate. With the goal of deciding on a bed-time meal, this would place me in the casein supplement corner. Then there is the efficiency of the protein -- that whey is more efficient than casein, at which point things start to become murky, especially with the solid foods lurking in the corner. To make matters worse, I've read that protein synthesis occurs more readily after a spike in amino acids than during a delayed release (please don't ask me to cite this study -- I can't find it.)

So this thread is to ask the more knowledgeable here for links to studies that deal with protein synthesis (magnitude/sustainability) and efficiency of protein types in the context of bed-time nutrition. My efforts at searching have left me frustrated.

[Emma-Leigh]

^
had to delete a bunch of copyright material... be careful what you post people. :o

A few recent studies on the subject:

http://journals.lww.com/co-clinicalnutrition/Abstract/2009/01000/Maximizing_muscle_protein_anabolism__the_role_of.1 2.aspx
Current Opinion in Clinical Nutrition and Metabolic Care:
January 2009 - Volume 12 - Issue 1 - p 66-71
doi: 10.1097/MCO.0b013e32831cef75

Maximizing muscle protein anabolism: the role of protein quality
Tang, Jason E; Phillips, Stuart M
Abstract
Purpose of review: Muscle protein synthesis (MPS) and muscle protein breakdown are simultaneous ongoing processes. Here, we examine evidence for how protein quality can affect exercise-induced muscle protein anabolism or protein balance (MPS minus muscle protein breakdown). Evidence is highlighted showing differences in the responses of MPS, and muscle protein accretion, with ingestion of milk-based and soy-based proteins in young and elderly persons.

Recent findings: Protein consumption, and the accompanying hyperaminoacidemia, stimulates an increase in MPS and a small suppression of muscle protein breakdown. Beyond the feeding-induced rise in MPS, small incremental addition of new muscle protein mass occurs following intense resistance exercise which over time (i.e. resistance training) leads to muscle hypertrophy. Athletes make use of the paradigm of resistance training and eating to maximize the gains in their skeletal muscle mass. Importantly, however, metabolically active skeletal muscle can offset the morbidities associated with the sarcopenia of aging such as type II diabetes, decline in aerobic fitness and the reduction in metabolic rate that can lead to fat mass accumulation.

Summary: Recent evidence suggests that consumption of different proteins can affect the amplitude and possibly duration of MPS increases after feeding and this effect interacts and is possibly accentuated with resistance exercise.


http://www.ncbi.nlm.nih.gov/pubmed/19589961
J Appl Physiol. 2009 Sep;107(3):987-92. Epub 2009 Jul 9.
Ingestion of whey hydrolysate, casein, or soy protein isolate: effects on mixed muscle protein synthesis at rest and following resistance exercise in young men.
Tang JE, Moore DR, Kujbida GW, Tarnopolsky MA, Phillips SM.

Department of Kinesiology-Exercise Metabolism Research Group, McMaster University, Hamilton, Ontario L8S 4K1, Canada.
This study was designed to compare the acute response of mixed muscle protein synthesis (MPS) to rapidly (i.e., whey hydrolysate and soy) and slowly (i.e., micellar casein) digested proteins both at rest and after resistance exercise. Three groups of healthy young men (n = 6 per group) performed a bout of unilateral leg resistance exercise followed by the consumption of a drink containing an equivalent content of essential amino acids (10 g) as either whey hydrolysate, micellar casein, or soy protein isolate. Mixed MPS was determined by a primed constant infusion of l-[ring-(13)C(6)]phenylalanine. Ingestion of whey protein resulted in a larger increase in blood essential amino acid, branched-chain amino acid, and leucine concentrations than either casein or soy (P < 0.05). Mixed MPS at rest (determined in the nonexercised leg) was higher with ingestion of faster proteins (whey = 0.091 +/- 0.015, soy = 0.078 +/- 0.014, casein = 0.047 +/- 0.008%/h); MPS after consumption of whey was approximately 93% greater than casein (P < 0.01) and approximately 18% greater than soy (P = 0.067). A similar result was observed after exercise (whey > soy > casein); MPS following whey consumption was approximately 122% greater than casein (P < 0.01) and 31% greater than soy (P < 0.05). MPS was also greater with soy consumption at rest (64%) and following resistance exercise (69%) compared with casein (both P < 0.01). We conclude that the feeding-induced simulation of MPS in young men is greater after whey hydrolysate or soy protein consumption than casein both at rest and after resistance exercise; moreover, despite both being fast proteins, whey hydrolysate stimulated MPS to a greater degree than soy after resistance exercise. These differences may be related to how quickly the proteins are digested (i.e., fast vs. slow) or possibly to small differences in leucine content of each protein.

PMID: 19589961 [PubMed - indexed for MEDLINE]

Publication Types, MeSH Terms, Substances
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Med Sci Sports Exerc. 2004 Dec;36(12):2073-81.
Ingestion of casein and whey proteins result in muscle anabolism after resistance exercise.
Tipton KD, Elliott TA, Cree MG, Wolf SE, Sanford AP, Wolfe RR.

Metabolism Unit, Shriners Hospitals for Children and Department of Surgery, The University of Texas Medical Branch, Galveston, TX 77550, USA. ktipton@utmb.edu
PURPOSE: Determination of the anabolic response to exercise and nutrition is important for individuals who may benefit from increased muscle mass. Intake of free amino acids after resistance exercise stimulates net muscle protein synthesis. The response of muscle protein balance to intact protein ingestion after exercise has not been studied. This study was designed to examine the acute response of muscle protein balance to ingestion of two different intact proteins after resistance exercise. METHODS: Healthy volunteers were randomly assigned to one of three groups. Each group consumed one of three drinks: placebo (PL; N = 7), 20 g of casein (CS; N = 7), or whey proteins (WH; N = 9). Volunteers consumed the drink 1 h after the conclusion of a leg extension exercise bout. Leucine and phenylalanine concentrations were measured in femoral arteriovenous samples to determine balance across the leg. RESULTS: Arterial amino acid concentrations were elevated by protein ingestion, but the pattern of appearance was different for CS and WH. Net amino acid balance switched from negative to positive after ingestion of both proteins. Peak leucine net balance over time was greater for WH (347 +/- 50 nmol.min(-1).100 mL(-1) leg) than CS (133 +/- 45 nmol.min(-1).100 mL(-1) leg), but peak phenylalanine balance was similar for CS and WH. Ingestion of both CS and WH stimulated a significantly larger net phenylalanine uptake after resistance exercise, compared with the PL (PL -5 +/- 15 mg, CS 84 +/- 10 mg, WH 62 +/- 18 mg). Amino acid uptake relative to amount ingested was similar for both CS and WH (approximately 10-15%). CONCLUSIONS: Acute ingestion of both WH and CS after exercise resulted in similar increases in muscle protein net balance, resulting in net muscle protein synthesis despite different patterns of blood amino acid responses.


J Am Coll Nutr. 2005 Apr;24(2):134S-139S.
Dietary protein to support anabolism with resistance exercise in young men.
Phillips SM, Hartman JW, Wilkinson SB.

Exercise Metabolism Research Group, Department of Kinesiology, McMaster University, 1280 Main St. West, Hamilton, ON L8S 4K1 CANADA. phillis@mcmaster.ca
Resistance exercise is fundamentally anabolic and as such stimulates the process of skeletal muscle protein synthesis (MPS) in an absolute sense and relative to skeletal muscle protein breakdown (MPB). However, the net effect of resistance exercise is to shift net protein balance (NPB = MPS - MPB) to a more positive value; however, in the absence of feeding NPB remains negative. Feeding stimulates MPS to an extent where NPB becomes positive, for a transient time. When combined, resistance exercise and feeding synergistically interact to result in NPB being greater than with feeding alone. This feeding- and exercise-induced stimulation of NPB is what, albeit slowly, results in muscle hypertrophy. With this rudimentary knowledge we are now at the point where we can manipulate variables within the system to see what impact these interventions have on the processes of MPS, MPB, and NPB and ultimately and perhaps most importantly, muscle hypertrophy and strength. We used established models of skeletal muscle amino acid turnover to examine how protein source (milk versus soy) acutely affects the processes of MPS and MPB after resistance exercise. Our findings revealed that even when balanced quantities of total protein and energy are consumed that milk proteins are more effective in stimulating amino acid uptake and net protein deposition in skeletal muscle after resistance exercise than are hydrolyzed soy proteins. Importantly, the finding of increased amino acid uptake would be independent of the differences in amino acid composition of the two proteins. We propose that the improved net protein deposition with milk protein consumption is also not due to differences in amino acid composition, but is due to a different pattern of amino acid delivery associated with milk versus hydrolyzed soy proteins. If our acute findings are accurate then we hypothesized that chronically the greater net protein deposition associated with milk protein consumption post-resistance exercise would eventually lead to greater net protein accretion (i.e., muscle fiber hypertrophy), over a longer time period. In young men completing 12 weeks of resistance training (5d/wk) we observed a tendency (P = 0.11) for greater gains in whole body lean mass and whole as greater muscle fiber hypertrophy with consumption of milk. While strength gains were not different between the soy and milk-supplemented groups we would argue that the true significance of a greater increase in lean mass that we observed with milk consumption may be more important in groups of persons with lower initial lean mass and strength such as the elderly.


J Int Soc Sports Nutr. 2007 Jul 23;4:4.
Effect of protein source and resistance training on body composition and sex hormones.
Kalman D, Feldman S, Martinez M, Krieger DR, Tallon MJ.

Miami Research Associates, Nutrition/Endocrinology Division, Miami, Florida, USA. dkalman@miamiresearch.com.
ABSTRACT: BACKGROUND: Evidence suggests an inverse relationship between soy protein intake and serum concentrations of male sex hormones. Anecdotal evidence indicates that these alterations in serum sex hormones may attenuate changes in lean body mass following resistance training. However, little empirical data exists regarding the effects of soy and milk-based proteins on circulating androgens and exercise induced body composition changes. METHODS: For 12 weeks 20 subjects were supplemented with 50 g per day of one of four different protein sources (Soy concentrate; Soy isolate; Soy isolate and whey blend, and Whey blend only) in combination with a resistance-training program. Body composition, testosterone, estradiol and sex hormone binding globulin (SHBG) were measured at baseline and week 12. RESULTS: Protein supplementation resulted in a significant increase in lean body mass independent of protein source (0.5 +/- 1.1 and 0.9 +/- 1.4 kg, p = 0.006, p = 0.007). No significant differences were observed between groups for total and free testosterone, SHBG, percentage body fat, BMI or body weight. The Testosterone/Estradiol ratio increased across all groups (+13.4, p = 0.005) and estradiol decreased (p = 0.002). Within group analysis showed significant increases in the Testosterone/Estradiol ratio in soy isolate + whey blend group (+16.3, p = 0.030). Estradiol was significantly lower in the whey blend group (-9.1 +/- 8.7 pg/ml, p = 0.033). CONCLUSION: This investigation shows that 12 week supplementation with soy protein does not decrease serum testosterone or inhibit lean body mass changes in subjects engaged in a resistance exercise program.

Moral of the story -
first rule: protein is good.
second rule: see point one. ;)

[OllieSA]

Much appreciated Emma-Leigh.

[mattyoung92]

Much appreciated Emma-Leigh.


So i guess from reading that stick to your whey for optimal post exercise amino acid uptake as well as during the day

and for all the fellas we can now rest easy in thinking that soy will decrease testosterone, but i have read elsewhere that it can raise your estrogen levels..