protein absorbtion rates

[pearl]

please, any doctor or really informed guy around here
:
i had this argument with my buddies for a long time now:
(we are at the point now where we discuss what is an emulsion and what is a suspension etc.)

the questions are:

1. what is the time that casein is absorbed in the bloodflow?
would a different amount of protein take longer/less to absorb?
2. same question with whey

3. does the aminoacids absorb in the blood all at one time, given that they come from the same protein source, or they absrob gradually, or what is the pattern?

4. if i have a blend of proteins what would be the time that is enough to absorb all of it.
compare 5g whey+5g casein vs 10g whey or 10g casein.

5. how different from the chemical point of view are the different sources of protein?

6. blends are really more efective than only one protein?
or is just marketing?

7. how is exactly protein present in the supplements?
just as aminoacids tied together or in the form of animal cells like in meat?

8. do you have some numbers on how much protein can the body absorb in a given amount of time, and what are the factors influencing that?

sorry for this load of questions, but i had nobody to turn to....

[hemants]

"1. what is the time that casein is absorbed in the bloodflow?
would a different amount of protein take longer/less to absorb?
2. same question with whey"

Studies seem to indicate that whey is absorbed faster than casein. However, this is only true if that is all that is ingested. Fat, fibre, and other food will all slow the digestion of protein so the differences in absorption speed will be masked. The only time I think protein absorption is relevant is post workout where it may be beneficial to have just whey protein.

"3. does the aminoacids absorb in the blood all at one time, given that they come from the same protein source, or they absrob gradually, or what is the pattern?
4. if i have a blend of proteins what would be the time that is enough to absorb all of it.
compare 5g whey+5g casein vs 10g whey or 10g casein."

I dunno.

"5. how different from the chemical point of view are the different sources of protein?"

Proteins are long chains of amino acids so they differ only in the ratio of amino acids. There is a physical structure as well but once digested, the body doesn't really care.


"6. blends are really more efective than only one protein?
or is just marketing?"

As long as you are not getting all your protein from once source, it's probably just marketing.

"7. how is exactly protein present in the supplements?
just as aminoacids tied together or in the form of animal cells like in meat?"

Yes, protein is protein ie. amino acid chains.

"8. do you have some numbers on how much protein can the body absorb in a given amount of time, and what are the factors influencing that?"

I don't know the source but "common wisdom" seems to suggest 40-60g at one meal depending on the size of the individual. More than that will definately be absorbed but possibly not utilized to build muscle (ie. protein, especially in the absence of carbs can be converted to glucose)

"sorry for this load of questions, but i had nobody to turn to...."

Sry I couldn't tell you anything more concrete. Personally I think protein absorption, quality, etc. etc. is overrated. If two trainers are getting the same total grams of protein per day, I think that factors other than the type of protein will largely determine their success. (ie. the rest of their diet, training protocol, rest, water intake, etc.)

[pearl]

thanks bro,

any other ideas?