Jocke77
2008-12-22, 10:47
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For the past year, researchers have been going back and forth debating which is more anabolic Whey Protein or Essential Amino Acids (EAA) . A few months ago, it seemed that EAA was the winner; in a previous study researchers administered either 15 grams of whey protein or 15 grams of EAA to elderly participants. They found that ingestion of 15 g of EAA more than doubles muscle protein balance in elderly persons when compared to that of the ingestion of 15 g of whey, which would support a greater importance of the EAA (as opposed to whey) in improving muscle protein synthesis in elderly persons. EAA seemed like the more anabolic supplement but the researchers went back and examined the data they found that 15 grams of whey protein contained only 7 grams of EAA! So the study did not have the exact same EAA mix for whey protein compared to the EAA mix (7 grams of EAA found in whey compared to 15 grams of EAA).
The same research group went back and administers a dose to dose comparison and administered 15 grams of whey which contains roughly 7 grams of EAA and compared it to an equivalent EAA dose (~6.72 g of EAA). To the researchers surprise, whey protein resulted in greater anabolic effects than EAA when compared dose per dose. The study reported that EAA are not solely responsible for the anabolic properties of whey protein. They researchers concluded that whey protein whole consumption is greater than the sum of its parts (EAA) or effects beyond that of just the amino acid content. So what ingredient in whey protein could be enhancing anabolic actions? Here is what is interesting, was that the two dosages each had the exact same dosage of leucine, so there was something else in whey protein causing the greater anabolic effect. The researchers hypothesized that the increase in the plasma concentration of the amino acid cysteine from whey protein, which has previously been found to augment muscle protein anabolism may have enhanced muscle protein synthesis. Whey protein resulted in a greater insulin response than EAA which also could have augmented the anabolic actions of whey protein. The researchers explained that whey protein is a potent stimulator of Gastric Inhibitory Polypeptide (GIP), also known as the glucose-dependent insulinotropic peptide. It is now believed that the function of GIP is to induce insulin secretion. Relative to that, it is known that whey protein is a strong stimulator of GIP secretagogue, possibly through bioactivepeptides present in whey or formed during its digestion, and that the plasma GIP concentration is greater after ingestion of intact protein than a similar amount of protein in the form of free Amino Acids. The researchers also commented that whey protein is inexpensive and also has additional health benefits that can’t be found in EAA. For example, cysteine-supported glutathione synthesis is implicated in protection against oxidative stress, whereas β-lactoglobulin and α-lactalbumin are major whey proteins modulating immune function. They researchers concluded that the anabolic actions of whey go beyond just EAA’s and the whole (Whey protein) are greater than the sum of parts (EAA).
Christos S. Katsanos, David L. Chinkes, Douglas Paddon-Jones, Xiao-jun Zhang, Asle Aarsland, Robert R. Wolfe. Whey protein ingestion in elderly persons results in greater muscle protein accrual than ingestion of its constituent essential amino acid content. Nutr Res. 2008 Oct;28(10):651-8.
For the past year, researchers have been going back and forth debating which is more anabolic Whey Protein or Essential Amino Acids (EAA) . A few months ago, it seemed that EAA was the winner; in a previous study researchers administered either 15 grams of whey protein or 15 grams of EAA to elderly participants. They found that ingestion of 15 g of EAA more than doubles muscle protein balance in elderly persons when compared to that of the ingestion of 15 g of whey, which would support a greater importance of the EAA (as opposed to whey) in improving muscle protein synthesis in elderly persons. EAA seemed like the more anabolic supplement but the researchers went back and examined the data they found that 15 grams of whey protein contained only 7 grams of EAA! So the study did not have the exact same EAA mix for whey protein compared to the EAA mix (7 grams of EAA found in whey compared to 15 grams of EAA).
The same research group went back and administers a dose to dose comparison and administered 15 grams of whey which contains roughly 7 grams of EAA and compared it to an equivalent EAA dose (~6.72 g of EAA). To the researchers surprise, whey protein resulted in greater anabolic effects than EAA when compared dose per dose. The study reported that EAA are not solely responsible for the anabolic properties of whey protein. They researchers concluded that whey protein whole consumption is greater than the sum of its parts (EAA) or effects beyond that of just the amino acid content. So what ingredient in whey protein could be enhancing anabolic actions? Here is what is interesting, was that the two dosages each had the exact same dosage of leucine, so there was something else in whey protein causing the greater anabolic effect. The researchers hypothesized that the increase in the plasma concentration of the amino acid cysteine from whey protein, which has previously been found to augment muscle protein anabolism may have enhanced muscle protein synthesis. Whey protein resulted in a greater insulin response than EAA which also could have augmented the anabolic actions of whey protein. The researchers explained that whey protein is a potent stimulator of Gastric Inhibitory Polypeptide (GIP), also known as the glucose-dependent insulinotropic peptide. It is now believed that the function of GIP is to induce insulin secretion. Relative to that, it is known that whey protein is a strong stimulator of GIP secretagogue, possibly through bioactivepeptides present in whey or formed during its digestion, and that the plasma GIP concentration is greater after ingestion of intact protein than a similar amount of protein in the form of free Amino Acids. The researchers also commented that whey protein is inexpensive and also has additional health benefits that can’t be found in EAA. For example, cysteine-supported glutathione synthesis is implicated in protection against oxidative stress, whereas β-lactoglobulin and α-lactalbumin are major whey proteins modulating immune function. They researchers concluded that the anabolic actions of whey go beyond just EAA’s and the whole (Whey protein) are greater than the sum of parts (EAA).
Christos S. Katsanos, David L. Chinkes, Douglas Paddon-Jones, Xiao-jun Zhang, Asle Aarsland, Robert R. Wolfe. Whey protein ingestion in elderly persons results in greater muscle protein accrual than ingestion of its constituent essential amino acid content. Nutr Res. 2008 Oct;28(10):651-8.