Protein Hydrolysates In Sports And Exercise: A Brief Review

[3XL]

PROTEIN HYDROLYSATES IN SPORTS AND EXERCISE: A BRIEF REVIEW


Anssi H. Manninen

Department of Physiology, Faculty of Medicine, University of Oulu, Finland

Received 23 March 2004
Accepted 06 April 2004
Published 01 June 2004

© Journal of Sports Science and Medicine (2004) 3, 60-63

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ABSTRACT
Protein can be hydrolyzed, producing small chains of amino acids called peptides. Several studies have shown that protein hydrolysates containing mostly di- and tripeptides are absorbed more rapidly than free form amino acids and much more rapidly than intact proteins. In addition, there is recent evidence that protein hydrolysate ingestion has strong insulinotropic effect. Thus, recovery sports drinks containing protein hydrolysates may be of great value.

KEY WORDS:Proteins, amino acids, protein hydrolysates, ergogenic aids, sports supplements



INTRODUCTION
Today, we have four ways to get amino acids into the bloodstream: 1) whole food proteins: 2) intact protein supplements, 3) free form amino acids, and 4) protein hydrolysates (Manninen, 2002). Protein can be hydrolyzed, producing small chains of amino acids called peptides. This process mimics our own digestive actions thus making it an ideal way to process protein.

Protein hydrolysates are produced from purified protein sources by heating with acid or preferably, addition of proteolytic enzymes, followed by purification procedures (Bucci and Unlu, 2000). Enzyme hydrolysis is greatly preferred because acid hydrolysis oxidizes cysteine and methionine, destroys some serine and threonine, and converts glutamine and asparagine to glutamate and aspartate, respectively, lowering protein quality and biological value (Bucci and Unlu, 2000).

Several studies have shown that protein hydrolysates containing mostly di- and tripeptides are absorbed more rapidly than free form amino acids and much more rapidly than intact proteins (Di Pasquale, 1997). The considerably greater absorption rate of amino acids from the dipeptide than from the amino acid mixture appears to be the result of uptake by a system that has a greater transport capacity than amino acid carrier system, thus minimizing competition among its substrates (Di Pasquale, 1997). This is a desirable trait for athletes who wish to maximize amino acid delivery to muscle.

However, whether this apparent advantage over ingestion of foodstuffs has a practical effect of faster muscle mass accretion or improved recovery from exercise has not been adequately studied in exercising individuals. Nevertheless, documented advantages (faster uptake of amino acids, higher biological value) remain attractive to consumers. In addition, there is recent evidence that protein hydrolysate ingestion has strong insulinotropic effect. Thus, this article examines some science behind protein hydrolysates applied to sports and exercise.

Principal actions of insulin related to sports and exercise

Insulin is peptide hormone produced by the beta cells of the pancreas. Physiological effects of insulin are far-reaching and complex. They are conveniently divided into rapid, intermediate, and delayed actions, as listed in Table 1. The best know is the hypoglycemic effect, but there are additional effects on amino acid and electrolyte transport, many enzymes, and growth. The net effect of the hormone is storage of carbohydrate, protein, and fat.

From our understanding of insulin physiology we can see different ways in which insulin might be a performance-enhancing agent:



Through facilitating glucose entry into cells in amounts greater than needed for cellular respiration it will stimulate glycogen formation. Thus, insulin will both increase muscle glycogen concentrations prior to exercise and in the recovery phase after exercise.

Insulin is also being used in more haphazard way, particularly to increase muscle mass in bodybuilders. It has been long known that insulin-treated patients with diabetes have an increase in lean body mass when compared with matched controls (Sonksen 2001).
Effects of protein and amino acids on insulin secretion

Formerly, it was believed that insulin secretion was controlled almost entirely by the blood glucose concentration. However, as more has been learned about the metabolic functions of insulin for protein and lipid metabolism, it has become apparent that blood amino acids and other factors also play important roles in controlling insulin secretion.

Protein meals, infusion of physiological amino acid mixtures, or certain individual amino acids cause insulin release in humans even under conditions where the blood sugar changes little from its basal level (Newgard and Matschinksy 2001). However, changes of blood sugar levels markedly influence the responsiveness of beta cells to individual amino acids. For example, hypoglycemia reduces insulin release to amino acid mixtures and most individual amino acids (Newgard and Matschinksy 2001). Studies on isolated perfused rat pancreas and islets have demonstrated that physiological amino acid mixtures and even pharmacological concentrations of individual amino acids require the presence of permissive levels of glucose to be effective beta cell stimulants. However, leucine is an exception (Newgard and Matschinksy, 2001).

In a recent well-controlled study by van Loon et al. (2000a), a total of 10 drinks were tested in 8 nonobese males after an overnight fast to investigate the insulinotropic potential of several free amino acids, protein hydrolysates, and an intact protein. At 0, 30, 60, and 90 min, the subjects received a beverage 3.5 mL·kg-1 to ensure a given dose of 0.8 g carbohydrate·kg-1 (50% as glucose and 50% as maltodextrin) and 0.4 g·kg-1 of an amino acid and protein hydrolysate mixture every hour. The results of this study indicate that oral ingestion of some amino acid mixtures in combination with carbohydrates can produce strong insulinotropic effects.

To compare the insulinotropic effect of the ingestion of the protein hydrolysates with that of an intact protein, sodium-caseinate was provided in one of the drinks. This resulted in an insulin response that was not significantly different from that found with the control trial (30% greater) and tended to be less than the responses observed after ingestion of the protein hydrolysates. After ingestion of the intact protein, plasma amino acid responses over this 2-h period were in general lower than the responses observed after ingestion of the protein hydrolysates.

Regression analysis of the insulin responses and the changes in the plasma amino acids concentrations over the 2-h period showed a strong positive correlation between the observed insulin response and changes in plasma leucine (p < 0.003), phenylalanine (p < 0.0001), and tyrosine (p < 0.0001) concentrations. As pointed out by authors, this agrees with several in vivo studies in which -cells of pancreas were incubated with leucine and phenyalanine and with the in vivo studies by Floyd et al. in which amino acids were infused (for references see van Loon et al., 2000a). The correlation observed with tyrosine concentrations may be explained by the fact that tyrosine is formed by the hydroxylation of phenylalanine when large amounts of phenyalanine are ingested. Interestingly, the addition of free glutamine hardly influenced plasma glutamine levels. Also, the data in this study show clearly that oral ingestion of large amounts of free arginine is not an effective means of increasing plasma insulin concentrations and plasma arginine concentrations.
The main conclusion is that oral intake of protein hydrolysates and amino acids in combination with carbohydrates can result in an insulinotropic effect as much as 100% greater than with the intake of carbohydrates only.

In another excellent study by van Loon et al. (2000b), after an overnight fast, eight male cyclists visited at laboratory on five occasions, during which a control and two different beverage compositions in two different doses were tested. After they performed a glycogen-depletion protocol, subjects received a beverage (3.5 mL·kg-1) every 30 min ensure an intake of 1.2 g·kg-1·h-1 carbohydrate and 0, 0.2 or 0.4 g·kg-1·h-1 protein hydrolysate and amino acid mixture.

After the insulin response was expressed as the area under curve, only the ingestion of the beverages containing protein hydrolysate, leucine and phenylalanine resulted in a marked increase in insulin response compared with carbohydrate-only trial. Further, a dose-related effect existed because doubling the dose (0.2-0.4 g·kg-1·h-1) led to an additional rise in insulin response (p < 0.05). Plasma leucine, phenylalanine and tyrosine concentrations showed strong correlations with the insulin response (p < 0.0001).

In addition, plasma amino acid concentrations were generally lower after the ingestion of drinks contraining protein hydrolysate + phenylalanine + leucine compared to with the control drinks, although in the latter, considerable amount of protein and amino acids were ingested. As pointed out by authors, this seems to suggest that tissue amino acid uptake and possibly also post-exercise net muscle protein balance were increased after the ingestion of this insulintropic mixture.

This would be in line with several studies demonstrating that an increase in plasma insulin concentration, during conditions of hyperaminoacidemia, further increases net muscle protein balance in vivo in humans (for references, see van Loon et al., 2000a.). Such a stimulating effect on net protein balance may in part also be a consequence of a stimulating effect of leucine on skeletal muscle protein synthesis, independent of an increase in insulin levels (Anthony et al., 2000). According to authors, this study provided a practical tool to markedly elevate insulin levels and plasma amino acid availability through dietary manipulation, which may be of great value in recovery sports drinks.
More recently, Calbet and MacLean (2002) reported that the combined administration of glucose and protein hydrolysates stimulates a synergistic release of insulin, regardless of the protein source. They concluded that peptide hydrolysates are absorbed at a faster rate from the small intestine than are whole milk proteins delivered as a milk solution, as reflected by the rapid increase in the plasma concentration of branched-chain amino acids in peripheral blood.

Further, the whey peptide hydrolysate elicited the greatest availability of amino acids during the 3-h postprandial period. According to Calbet and MacLean (2002), the association of high levels of plasma amino acids and insulin might explain a superiority of peptide hydrolysates over whole proteins in promoting better nitrogen utilization, especially when administered in combination with glucose.


CONCLUSION
Recovery sports drinks containing protein hydrolysates and insulinotropic amino acids may be of great value. However, the potential to stimulate post-exercise net muscle protein anabolism, and the mechanisms involved, remains to be investigated.


KEY POINTS
Protein hydrolysates containing mostly di- and tripeptides are absorbed more rapidly than free form amino acids and much more rapidly than intact proteins.
" Oral intake of protein hydrolysates and amino acids in combination with carbohydrates can result in an insulinotropic effect as much as 100% greater than with the intake of carbohydrates only.
Recovery sports drinks containing protein hydrolysates and insulinotropic amino acids may be of great value, but more research is needed before firm conclusions can be drawn.

AUTHOR BIOGRAPHY

Anssi H. MANNINEN
Affiliation:Department of Physiology, Faculty of Medicine, University of Oulu, Finland
Degree: M.H.S. in Sports Medicine, University of Kuopio, Finland
Research interests: Sports nutrition, ergogenic aids, exercise metabolism and obesity
Email: sportsnutrition@luukku.com


REFERENCES
Anthony, J.C., Anthony, T.G., Kimball, S.R., Vary T.C. and Jefferson, L.S. (2000) Orally administered leucine stimulates protein synthesis in skeletal muscle of postabsorptive rats in association with increases eIF4F formation. Journal of Nutrition 130, 139-145.

Bucci, L.R. and Unlu, L. (2000) Protein and amino acid supplements in exercise and sport. In: Energy-yielding macronutrients and energy metabolism in sports nutrition. Eds: Wolinsky, I., Driskell, J.A. Boca Raton, FL: CRC Press. 191-212.

Calbet, J.A.L. and MacLean, D.A. (2002) Plasma glucagons and insulin responses depend on the rate of appearance of amino acids after ingestion of different protein solutions in humans. Journal of Nutrition 132, 2174-2182.

Di Pasquale, M.G. (1997) Amino acids and proteins for the athlete: The anabolic edge. Boca Raton, FL: CRC Press.

Ganong, W.F. (2001) Endocrine functions of the pancreas and regulation of carbohydrate metabolism. In: Review of medical physiology. New York: McGraw-Hill. 322-343.

Manninen, A.H. (2002) Protein metabolism in exercising humans with special reference to protein supplementation. Master thesis. Department of Physiology, Faculty of Medicine, University of Kuopio, Finland.

Newgard, C.B. and Matschinksy, F.M. (2001) Substrate control of insulin release. In: Handbook of physiology: Section 7 the endocrine system: Volume II the endocrine pancreas and regulation of metabolism. Oxford: Oxford University Press. 125-151.

Sonksen, P.H. (2001) Insulin, growth hormone, and sport. Journal of Endocrinology 170, 13-25.

van Loon, L.J., Saris, W.H.M., Verhagen, H. and Wagenmakers, A.J. (2000a) Plasma insulin responses after ingestion of different amino acid or protein mixtures with carbohydrate. American Journal of Clinical Nutrition 72, 96-105.

van Loon, L.J., Kruijshoop, M., Verhagen, H., Saris, W.H. and Wagenmakers, A.J. (2000b) Ingestion of protein hydrolysate and amino acid-carbohydrate mixtures increases postexercise plasma insulin responses in men. Journal of Nutrition 130, 2508-2513.

JSSM- 2004, Vol.3, Issue 2, 60 - 63

[chunky]

ben je zelf al lang genoeg aan het 'testen' geweest om te kunnen zeggen dat hydrolisaat een meerwaarde heeft tov bijvoorbeeld isolaat?

[elderson]

Origineel gepost door 3XL

PROTEIN HYDROLYSATES IN SPORTS AND EXERCISE: A BRIEF REVIEW
KEY POINTS
Protein hydrolysates containing mostly di- and tripeptides are absorbed more rapidly than free form amino acids and much more rapidly than intact proteins.
" Oral intake of protein hydrolysates and amino acids in combination with carbohydrates can result in an insulinotropic effect as much as 100% greater than with the intake of carbohydrates only.
Recovery sports drinks containing protein hydrolysates and insulinotropic amino acids may be of great value, but more research is needed before firm conclusions can be drawn.

Goed artikel!

Jammer dat de plaatjes ontbreken waarin het tijdsverloop tussen inname en effekt duidelijk wordt bij verschillende drankjes & kombinaties. Ik zag ze ook niet in het artikel zelf.

Ik wil weten hoe snel na de inname van hydrolysaat je piek begint en hoe lang die duurt. Een snelle piek die een halfuur na de training begint en een halfuur later weer over is is niet zo interessant, vind ik.

Wat je zou willen is dat je eiwitpiek in het bloed samenvalt met extra glukose, maar als je het samen inneemt is de glukosepiek zowizo sneller.

In het onderzoek lossen ze dat op door telkens glukose toe te blijven voeren zodat die altijd hoog is, maar dat is ook precies het recept om vetmassa aan te maken.

Een bedenking is dat het niet persee goed is om een snelle en hoge piek van insuline te hebben. Voor bb is het MI belangrijker om gemiddeld een netto positieve eiwitbalans te hebben, bij zo min mogelijk vetopbouw. Hoge insulinepieken plus voeding slaan gegarandeerd ook veel vet op.

[BBD]

Origineel gepost door 3XL

Anssi H. Manninen

[eq_909]

Origineel gepost door BBD

Als je er nu ook nog een reden bij zet waarom, hebben we er ook nog iets aan misschien

[BBD]

Origineel gepost door eq_909

Als je er nu ook nog een reden bij zet waarom, hebben we er ook nog iets aan misschien

Hij gaat gewoon over internet op zoek naar mensen om die hopelijk the bashen met zn insane kennis, maar gaat alleen elke keer hard op zn bek.

Voorbeeldje:
Body Recomposition Forums

En hij published wel eens wat. Zn carb review was zo ellendig slecht dat ik niets meer van hem lees.

[Sephirothsnake]

En waar kan je wei hydrolisaat kopen?

[Bosna Animal]

http://www.fitnessnet.nl/fitnessnet....drolisaat.html

hier kun je t kopen wel erg duur.

[3XL]

Mischien dat je wat met Smoothmold kan regelen

echte hydrolized whey voor betaalbare prijs. wie wil ook?

[Blokkieblok]

das nie normaal man die prijzen wat is idd de meerwaarden hydr tov iso?

[chunky]

de snelheid van opname blok, waardoor je dus eerder je amino's in je bloed hebt.

[Blokkieblok]

Aha ok , maar voor die prijs mmmm

[Jaccis]

is het wat betreft Hydro-Iso-concentraat whey niet gewoon zo dat wanneer je je iname tijd tav. je training precies plant/berekend je aan je Whey concentraat, zelf je '' hydro-isolaat'' maakt ?

Snappen jullie wat ik bedoel, kan het niet anders uitleggen

[balletje]

heeft denk te maken met de opnametijd na de training. je kan het plannen door de tijd voor je trainen voldoende voorraad in huis te hebben.
hydro en iso zijn verschillende processen van whey eiwit scheiden bij af afromen van kaas , en daardoor een wat zuivere vorm heb ik es gelezen.

[3XL]

Origineel gepost door Jaccis

is het wat betreft Hydro-Iso-concentraat whey niet gewoon zo dat wanneer je je iname tijd tav. je training precies plant/berekend je aan je Whey concentraat, zelf je '' hydro-isolaat'' maakt ?

Snappen jullie wat ik bedoel, kan het niet anders uitleggen

Volgens mij bedoel je dat je het idee heb dat als je 3 uur van te vioren concentraat neem je hetzelfde bereik als waneer je 1 uur van te voren hydrolisaat neem?


Theoretisch mischien wel, maar in de praktijk betekend dit dat je 3 uur lang niets meer te eten zou moeten nemen omdat dit de opname beinvloed.