Don't Waste Money on Hydrolysate
by Lyle McDonald
Deglaire et al. Hydrolyzed dietary casein as compared with the intact protein reduces postprandial peripheral, but not whole-body, uptake of nitrogen in humans. Am J Clin Nutr. (2009) 90(4):1011-22.
BACKGROUND: Compared with slow proteins, fast proteins are more completely extracted in the splanchnic bed but contribute less to peripheral protein accretion; however, the independent influence of absorption kinetics and the amino acid (AA) pattern of dietary protein on AA anabolism in individual tissues remains unknown. OBJECTIVE: We aimed to compare the postprandial regional utilization of proteins with similar AA profiles but different absorption kinetics by coupling clinical experiments with compartmental modeling. DESIGN: Experimental data pertaining to the intestine, blood, and urine for dietary nitrogen kinetics after a 15N-labeled intact (IC) or hydrolyzed (HC) casein meal were obtained in parallel groups of healthy adults (n = 21) and were analyzed by using a 13-compartment model to predict the cascade of dietary nitrogen absorption and regional metabolism. RESULTS: IC and HC elicited a similar whole-body postprandial retention of dietary nitrogen, but HC was associated with a faster rate of absorption than was IC, resulting in earlier and stronger hyperaminoacidemia and hyperinsulinemia. An enhancement of both catabolic (26%) and anabolic (37%) utilization of dietary nitrogen occurred in the splanchnic bed at the expense of its further peripheral availability, which reached 18% and 11% of ingested nitrogen 8 h after the IC and HC meals, respectively. CONCLUSIONS: The form of delivery of dietary AAs constituted an independent factor of modulation of their postprandial regional metabolism, with a fast supply favoring the splanchnic dietary nitrogen uptake over its peripheral anabolic use. These results question a possible effect of ingestion of protein hydrolysates on tissue nitrogen metabolism and accretion.
My Comments: Ever since the pioneering work in the 90???s on fast and slow proteins, there has been continued interest in the digestion speed of proteins and how that impacts on metabolism, performance and, of course, muscle growth. In recent years, there have been many claims made for the superiority of faster proteins to slower in terms of ???speeding amino acids to muscle??? in terms of promoting growth.
As well, as many may note, a recent commercial product (T-nations Anaconda), who???s anabolic claims were analyzed in perhaps the most commented article on the site in Alan???s Aragon???s guest article Supplement Marketing on Steroids, has recently been released to the market.
For background, hydrolysates are simply whole proteins that have been pre-digested (through the addition of enzymes during production) to some degree. The theory being that, due to this pre-digestion, the hydrolysate will be digested in the stomach faster, getting aminos into the bloodstream faster and, presumably, having a better effect on skeletal muscle than slower proteins.
But is it true? Guess.
The above study examined this issue by feeding 21 subjects 2 test meals containing ~26.5 grams of either intact casein or it???s hydrolysate; the protein had been marked with radioactive nitrogen so that it???s fate after ingestion could be tracked over the next 8 hours. The test meals also contained 96 grams of carbohydrate and 23 grams of fat; this is worth noting as adding other nutrients to fast proteins often makes them behave more like slow proteins. I???ll spare you the methodology, sufficed to say that tracking protein after it enters the body is brutally complicated and involves a lot of modelling and various measurements of blood amino acid levels and such.
Here???s what the study found. Over the time course studied (8 hours after ingestion), the hydrolyzed casein product showed greater losses from digestion (that is, less was absorbed). As well, a greater amount of the hydrolysate was oxidized for energy through deamination (a process by which the amino group is stripped off the carbon backbone). Finally, a larger amount of the casein hydrolysate was used by the splanchnic bed (gut and intestines) with significantly less of the total protein reaching the bloodstream or peripheral tissues (muscles).
To quote the researchers:
Despite similar overall net postprandial protein utilization, our results indicate important differences in metabolic partitioning and kinetics between protein sources characterized by a preferential utilization of dietary nitrogen by for splanchnic protein syntheses after HC [hydrolyzed casein] ingestion at the expense of the incorporation into peripheral tissues.
Translating that into English: hydrolyzed casein is digested more poorly, gets burned for energy to a greater degree and gets used more by the gut than intact casein; the end result of this is that hydrolyzed casein provides LESS amino acids to skeletal muscle after ingestion than intact casein protein.
So not only is the claim that hydrolysates are better at providing aminos faster to skeletal muscle wrong, the reality is actually exactly reversed: intact casein is better for providing aminos to the muscle. I???d note that other studies have found this as well: in one, intact protein provided MORE branched-chain amino acids into the bloodstream than a hydrolyzed form.
I???d add to this that, as I discussed in The Protein Book, other data supports the idea that slower proteins may actually be superior to faster proteins for muscle growth; in one set of studies, for example, milk protein (a mix of slow and fast proteins) resulted in greater hypertophy than soy (a fast protein) over 8 weeks of training and supplementation. As well hydrolyzed proteins tend to taste like bleach; it???s no coincidence that Anaconda has to come with a separate flavoring intensifier: hydrolysates are gag-inducing. They can???t be consumed straight.
Summing up: Hydrolysates are not only not superior to intact protein in terms of providing amino acids to skeletal muscle, they are distinctly inferior. Their fast digestion speed leads to greater digestive losses, more oxidation via deamination and provides less amino acids to skeletal muscle. That???s on top of tasting like vomit. Or at least making you want to.
by Lyle McDonald
Deglaire et al. Hydrolyzed dietary casein as compared with the intact protein reduces postprandial peripheral, but not whole-body, uptake of nitrogen in humans. Am J Clin Nutr. (2009) 90(4):1011-22.
BACKGROUND: Compared with slow proteins, fast proteins are more completely extracted in the splanchnic bed but contribute less to peripheral protein accretion; however, the independent influence of absorption kinetics and the amino acid (AA) pattern of dietary protein on AA anabolism in individual tissues remains unknown. OBJECTIVE: We aimed to compare the postprandial regional utilization of proteins with similar AA profiles but different absorption kinetics by coupling clinical experiments with compartmental modeling. DESIGN: Experimental data pertaining to the intestine, blood, and urine for dietary nitrogen kinetics after a 15N-labeled intact (IC) or hydrolyzed (HC) casein meal were obtained in parallel groups of healthy adults (n = 21) and were analyzed by using a 13-compartment model to predict the cascade of dietary nitrogen absorption and regional metabolism. RESULTS: IC and HC elicited a similar whole-body postprandial retention of dietary nitrogen, but HC was associated with a faster rate of absorption than was IC, resulting in earlier and stronger hyperaminoacidemia and hyperinsulinemia. An enhancement of both catabolic (26%) and anabolic (37%) utilization of dietary nitrogen occurred in the splanchnic bed at the expense of its further peripheral availability, which reached 18% and 11% of ingested nitrogen 8 h after the IC and HC meals, respectively. CONCLUSIONS: The form of delivery of dietary AAs constituted an independent factor of modulation of their postprandial regional metabolism, with a fast supply favoring the splanchnic dietary nitrogen uptake over its peripheral anabolic use. These results question a possible effect of ingestion of protein hydrolysates on tissue nitrogen metabolism and accretion.
My Comments: Ever since the pioneering work in the 90???s on fast and slow proteins, there has been continued interest in the digestion speed of proteins and how that impacts on metabolism, performance and, of course, muscle growth. In recent years, there have been many claims made for the superiority of faster proteins to slower in terms of ???speeding amino acids to muscle??? in terms of promoting growth.
As well, as many may note, a recent commercial product (T-nations Anaconda), who???s anabolic claims were analyzed in perhaps the most commented article on the site in Alan???s Aragon???s guest article Supplement Marketing on Steroids, has recently been released to the market.
For background, hydrolysates are simply whole proteins that have been pre-digested (through the addition of enzymes during production) to some degree. The theory being that, due to this pre-digestion, the hydrolysate will be digested in the stomach faster, getting aminos into the bloodstream faster and, presumably, having a better effect on skeletal muscle than slower proteins.
But is it true? Guess.
The above study examined this issue by feeding 21 subjects 2 test meals containing ~26.5 grams of either intact casein or it???s hydrolysate; the protein had been marked with radioactive nitrogen so that it???s fate after ingestion could be tracked over the next 8 hours. The test meals also contained 96 grams of carbohydrate and 23 grams of fat; this is worth noting as adding other nutrients to fast proteins often makes them behave more like slow proteins. I???ll spare you the methodology, sufficed to say that tracking protein after it enters the body is brutally complicated and involves a lot of modelling and various measurements of blood amino acid levels and such.
Here???s what the study found. Over the time course studied (8 hours after ingestion), the hydrolyzed casein product showed greater losses from digestion (that is, less was absorbed). As well, a greater amount of the hydrolysate was oxidized for energy through deamination (a process by which the amino group is stripped off the carbon backbone). Finally, a larger amount of the casein hydrolysate was used by the splanchnic bed (gut and intestines) with significantly less of the total protein reaching the bloodstream or peripheral tissues (muscles).
To quote the researchers:
Despite similar overall net postprandial protein utilization, our results indicate important differences in metabolic partitioning and kinetics between protein sources characterized by a preferential utilization of dietary nitrogen by for splanchnic protein syntheses after HC [hydrolyzed casein] ingestion at the expense of the incorporation into peripheral tissues.
Translating that into English: hydrolyzed casein is digested more poorly, gets burned for energy to a greater degree and gets used more by the gut than intact casein; the end result of this is that hydrolyzed casein provides LESS amino acids to skeletal muscle after ingestion than intact casein protein.
So not only is the claim that hydrolysates are better at providing aminos faster to skeletal muscle wrong, the reality is actually exactly reversed: intact casein is better for providing aminos to the muscle. I???d note that other studies have found this as well: in one, intact protein provided MORE branched-chain amino acids into the bloodstream than a hydrolyzed form.
I???d add to this that, as I discussed in The Protein Book, other data supports the idea that slower proteins may actually be superior to faster proteins for muscle growth; in one set of studies, for example, milk protein (a mix of slow and fast proteins) resulted in greater hypertophy than soy (a fast protein) over 8 weeks of training and supplementation. As well hydrolyzed proteins tend to taste like bleach; it???s no coincidence that Anaconda has to come with a separate flavoring intensifier: hydrolysates are gag-inducing. They can???t be consumed straight.
Summing up: Hydrolysates are not only not superior to intact protein in terms of providing amino acids to skeletal muscle, they are distinctly inferior. Their fast digestion speed leads to greater digestive losses, more oxidation via deamination and provides less amino acids to skeletal muscle. That???s on top of tasting like vomit. Or at least making you want to.
