Protein Supplements: which are best?

Very Nice!

Thanks,

W.

Good post. I think we gotta have the best of both worlds.

http://www.ncbi.nlm.nih.gov/entrez/...t_uids=17093159

casein vs whey

So from the above study, we might conclude that total milk protein is better than casein is better than milk isolate. Here is another study that essentially says the same as the initial study that i posted. The conclusions were that casein reulted in significantly less total protein turnover HOWEVER whey resulted in an almost 50% greater protein synthesis.

It is apparent to me now that what we may really want is a mixture of whey/isolate/casein/TMP. That would maximize protein synthesis and minimize protein turnover.

jb

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Slow and fast dietary proteins differently modulate postprandial protein accretion.Boirie Y, Dangin M, Gachon P, Vasson MP, Maubois JL, Beaufrere B.
Laboratoire de Nutrition Humaine, Universite Clermont Auvergne, Centre de Recherche en Nutrition Humaine, BP 321, 63009 Clermont-Ferrand Cedex 1, France.

The speed of absorption of dietary amino acids by the gut varies according to the type of ingested dietary protein. This could affect postprandial protein synthesis, breakdown, and deposition. To test this hypothesis, two intrinsically 13C-leucine-labeled milk proteins, casein (CAS) and whey protein (WP), of different physicochemical properties were ingested as one single meal by healthy adults. Postprandial whole body leucine kinetics were assessed by using a dual tracer methodology. WP induced a dramatic but short increase of plasma amino acids. CAS induced a prolonged plateau of moderate hyperaminoacidemia, probably because of a slow gastric emptying. Whole body protein breakdown was inhibited by 34% after CAS ingestion but not after WP ingestion. Postprandial protein synthesis was stimulated by 68% with the WP meal and to a lesser extent (+31%) with the CAS meal. Postprandial whole body leucine oxidation over 7 h was lower with CAS (272 +/- 91 micromol.kg-1) than with WP (373 +/- 56 micromol.kg-1). Leucine intake was identical in both meals (380 micromol.kg-1). Therefore, net leucine balance over the 7 h after the meal was more positive with CAS than with WP (P < 0.05, WP vs. CAS). In conclusion, the speed of protein digestion and amino acid absorption from the gut has a major effect on whole body protein anabolism after one single meal. By analogy with carbohydrate metabolism, slow and fast proteins modulate the postprandial metabolic response, a concept to be applied to wasting situations.

Ah, once you start downthis path..... If we suggest that our gola is to maximize a variable thought to be consistent with anabolism, it would seem that casein which generates a higher leucine level by far than whey would be the choice. Here is a study that one might interpret to read amultiple smaller doses of whey spread out over several hours is significantly more effective.

jb

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Am J Physiol Endocrinol Metab. 2001 Feb;280(2):E340-8. Links
The digestion rate of protein is an independent regulating factor of postprandial protein retention.Dangin M, Boirie Y, Garcia-Rodenas C, Gachon P, Fauquant J, Callier P, Ballevre O, Beaufrere B.
Laboratoire de Nutrition Humaine, Centre de Recherche en Nutrition Humaine, Universite Clermont Auvergne, 63009 Clermont-Ferrand, France.

To evaluate the importance of protein digestion rate on protein deposition, we characterized leucine kinetics after ingestion of "protein" meals of identical amino acid composition and nitrogen contents but of different digestion rates. Four groups of five or six young men received an L-[1-13C]leucine infusion and one of the following 30-g protein meals: a single meal of slowly digested casein (CAS), a single meal of free amino acid mimicking casein composition (AA), a single meal of rapidly digested whey proteins (WP), or repeated meals of whey proteins (RPT-WP) mimicking slow digestion rate. Comparisons were made between "fast" (AA, WP) and "slow" (CAS, RPT-WP) meals of identical amino acid composition (AA vs. CAS, and WP vs. RPT-WP). The fast meals induced a strong, rapid, and transient increase of aminoacidemia, leucine flux, and oxidation. After slow meals, these parameters increased moderately but durably. Postprandial leucine balance over 7 h was higher after the slow than after the fast meals (CAS: 38 +/- 13 vs. AA: -12 +/- 11, P < 0.01; RPT-WP: 87 +/- 25 vs. WP: 6 +/- 19 micromol/kg, P < 0.05). Protein digestion rate is an independent factor modulating postprandial protein deposition.

Posted by: jboldman

It is apparent to me now that what we may really want is a mixture of whey/isolate/casein/TMP. That would maximize protein synthesis and minimize protein turnover.

jb

exactly, hence my endorsement...

just think of whey as the glucose of proteins... would you eat glucose goo every two hours for energy? your primary source of carb?

i do think the table shifts a bit when your talking about enhance athletes, i would assume while on aas primarily the more anabolic ones whey would be used much more effeciently

so now we have to determine the correct ratios. or situations.

jb

Posted by: jboldman

Am J Physiol Endocrinol Metab. 2001 Feb;280(2):E340-8. Links
The digestion rate of protein is an independent regulating factor of postprandial protein retention.Dangin M, Boirie Y, Garcia-Rodenas C, Gachon P, Fauquant J, Callier P, Ballevre O, Beaufrere B.
Laboratoire de Nutrition Humaine, Centre de Recherche en Nutrition Humaine, Universite Clermont Auvergne, 63009 Clermont-Ferrand, France.

This is the study I had on hand. Whey - 4 hours, casein - 7 hours. Here is a graph to go with it: Attachment: whey vs casein.gif
This has been downloaded 77 time(s).

should I conclude that the whey used throughout the day must be replaced by a caseine before retiring?

yes, that is a reasonable assumption. for pre-workout i see whey being the choice and for post workout a combination of casein and whey.

jb

Posted by: jboldman

yes, that is a reasonable assumption. for pre-workout i see whey being the choice and for post workout a combination of casein and whey.

jb

Yes. I mix whey and low fat cheese!

Does casein slow down the absorbtion of whey ?

i dont see how. For protein systhesis we want a fast acting protein like whey with a slow acting protein like casein for longer turn nitrogen balance.

jb

Posted by: pSimonkey

Does casein slow down the absorbtion of whey ?

No, but there are other ways, ie adding fat to your shake.