We present to you Yves Boirie and his study dating from 1997. Here are all the details for a better understanding.
- Yves Boirie: a little history
- What proteins did Yves Boirie use?
- The real conclusions of Yves Boirie's study
Yves Boirie: a little history
It was in 1997 that a French study carried out by Yves Boirie revolutionized the use of proteins (1) .
Yves Boirie's study showed, for the first time, that these two proteins should not be pitted against each other , because their effects were different and complementary. These findings have been widely echoed by protein sellers. The wars of whey against casein and vice versa have stopped.
All the supplement sellers started selling both types of protein instead of only specializing in one or the other, as they did before.
What proteins did Yves Boirie use?
When we refer to Yves Boirie's study, we talk about whey and casein without really asking ourselves, among all the types of whey and the numerous caseins, which were used?
The answer to this question is crucial and yet little addressed.
For his research, Yves Boirie's first concern was to incorporate a radioactive tracer within the protein itself in order to be able to monitor its assimilation once it has been absorbed by a person.
To do this, he gave radioactive leucine directly to a cow. He then collected the milk and filtered it himself. He therefore did not use just any protein, in particular those recovered from cheese factory trash (cheese whey).
He only used native protein (also called bio-active) of two types:
- A whey concentrate, native.
- A native micellar casein, obtained by filtration (2) .
The conclusions of his studies therefore do not apply to poor quality proteins such as:
- Commercial whey from cheese factories (full of amino acids broken down into GlycoMacroPeptides during cheese making: cheese whey);
- Calcium caseinates (inexpensive, but very poorly digestible);
- Caseins or total proteins obtained by co-precipitation rather than filtration.
(Note: Nutrimuscle only sells 100% native proteins, particularly whey. Nutrimuscle total protein is filtered like that of Yves Boiri e ).
The real conclusions of Yves Boirie's study
Compared to a native whey concentrate, we can expect a native whey isolate to be absorbed a little faster. Isolate is therefore probably a little more anabolic than a concentrate.
Compared to a native micellar casein, the total protein , which also contains 20% whey (compared to zero in that of Yves Boirie ), will therefore be absorbed more quickly. We can reasonably expect a 20% higher speed for it, which translates into a slightly more anabolic protein. On the other hand, its duration of action will at the same time be reduced by 20%, that is to say by approximately 2 hours less, or 5 hours compared to 7 for casein without whey.
The limitation of Yves Boirie's study is that it applies to people who do not play sports. When you take the protein after training and depending on the ingredients in your shake (addition of carbohydrates or not), you know that the speed of absorption will vary.
(1) Boirie Y. Slow and fast dietary proteins differently modulate postprandial protein accretion. Proc Natl Acad Sci US A. 1997 Dec 23;94(26):14930-5.
(2) Boirie Y. Production of large amounts of [13C]leucine-enriched milk proteins by lactating cows. J Nutr. 1995 Jan;125(1):92-8.