Soy Protein

[ex_banana-eater]

This shiz is DIRTY cheap. i want to know
(a) if soy protein is change to be a complete protein by adding the missing amino
(B) the biological value of soy protein

[Travis Stenersn]

The biological value of soy on a scale where human milk protein is 100 is 72. Whey is somewhere near 100.
I'm not sure about adding the missing amino, I did read that it's BV is changed quite a bit if you add methionine.

ExBE, head over to T-mag and type in Soy Protein into the search function. There are a few articles there that should change your mind about soy!

In short: It lowers T levels, lowers thyroid hormone levels, can heighten LDL levels, increase estrogen levels. It's nasty stuff.

[ex_banana-eater]

Originally posted by Travis Stenersn


In short: It lowers T levels, lowers thyroid hormone levels, can heighten LDL levels, increase estrogen levels. It's nasty stuff.

yea ive heard all that but it isnt very significant so i thought that could just go unoticed.

i am not familiar with the BV chart that you are referring to. what do you think the BV would be on a chart where eggs are 100, and whey isolate is 157?

[Travis Stenersn]

I couldn't find it's value on that chart. Try searching around google. Let me know if you do find it, because I would be curious.

It's not a HUGE deal, but there are better options out there. I don't know how cheap soy is, but there must be smoe cheap whey about the same price? Relying on soy as a major source of protein for an extended period of time WILL interfere with your gains!

[dnoel]

Originally posted by Travis Stenersn
The biological value of soy on a scale where human milk protein is 100 is 72. Whey is somewhere near 100.
I'm not sure about adding the missing amino, I did read that it's BV is changed quite a bit if you add methionine.

ExBE, head over to T-mag and type in Soy Protein into the search function. There are a few articles there that should change your mind about soy!

In short: It lowers T levels, lowers thyroid hormone levels, can heighten LDL levels, increase estrogen levels. It's nasty stuff.

bull****.
read this: http://www.sover.net/~timw/soyvswhy.htm

[ex_banana-eater]

http://www.nextproteins.com/2nd_level_prodinfo.html

this site shows soy being in the 70s. the whey they are talking about there i presume is whey protein CONCENTRATE

[Sobolic]

Soy protein has a BV of 72 which isn't bad, whey is superior at 112, but variety of protein sources is good. Soy does have it's upsides, it doesn't raise estrogen, it actually lowers estrogen, but causes a SLIGHT raise in progesterone, similar to estrogen. Now if soy were to be the main supplemented protein, this would not be a beneficial aspect. Soy Protein does not lower endogenous Testosterone levels either, it actually causes the body to release LH (leutinizing hormone) which attatchs to the leydigs cells (balls) and causes them to produce more Testosterone, however still companied by a slight raise in progesterone. Conclusion: Soy is a good protein, which gives us a slow digestiing steady feed of amino acids, but do to is Progest. Activity we would want to keep soy to a minimum, no more than .2g/lb of bodyweight. Soy with Casein before bed would be a great way to get a steady feed through the night. Soy is good, in moderation.

[D&G]

As I have stated before whey does not have a biological value of 159 - that would be matematically impossible - the single study that showed this was revealed to be an error made whereby chemical score was shown - a BV rating measures nitrogen given and nitrogen retained - 100 would imply that all of the nitrogen (protein) given was retained - therefore you cannot have a score of higher than 100 as it would imply more protein was retained than given!!! - not possible - its a scam used by unscurpulous companies - BV relates to measurements taken after 10 hours of fasting so its relevance to bb'ers is questionable anyway.

Another thing to consider - why would whey concentrate have a different BV to whey isolate? - the protein is identical it comes from the exact same place - one has less carbs and fats but that varies so much from brand to brand it is irrelevant, the protein in concentrate is exactly the same as isolate - don't be fooled by the supplement companies!!!!!!!!

[ex_banana-eater]

http://www.bodybuilding.com/fun/catprot.htm

hucum there big cat says isolate has a 157?


thanks for the advice, i will prolly get some soy to mix in my milk before bed because its cheap as shiznit!

[ex_banana-eater]

Originally posted by D&G
As I have stated before whey does not have a biological value of 159 - that would be matematically impossible - the single study that showed this was revealed to be an error made whereby chemical score was shown - a BV rating measures nitrogen given and nitrogen retained - 100 would imply that all of the nitrogen (protein) given was retained - therefore you cannot have a score of higher than 100 as it would imply more protein was retained than given!!! - not possible - its a scam used by unscurpulous companies - BV relates to measurements taken after 10 hours of fasting so its relevance to bb'ers is questionable anyway.

i thought 100 was based on egg protein, and anything better than that was given over 100%

[D&G]

No - the BV relates to nitogen given and nitrogen retained - you cannot retain more than you were given! - its simple mathematics - it is simply impossible for any protein to score over 100 - whole egg protein is actually superior to whey because it contains more amino acids - there is an excellent article by Lyle McDonald on thinkmuscle which explains this should you need a more expert opinion than mine.

Example:

1g of protein given and 1g protein retained = 100% - that is what whole egg scores to imply whey or any other protein scores above this implies
1g of protein given = 1.59g retained = 159% - so you have more protein retained than you were actually given!!!! basic maths says that can't happen.

Like I say if you don't want to believe me check out the work of Lyle McDonald who has written a comprehensive protein article which covers all of this.

[ex_banana-eater]

big cats article:

Biological Value

Proteins are ranked according to Biological Values (BV), arbitrary numbers given to protein to show comparisons in their availability within the body. At the time the system was introduced eggs were given the highest BV of 100 because they are the most bio-available natural protein. Afterwards whey was isolated from milk and shown to have a higher BV, and depending on the process used can yield percentage from 104 to 154 on the scale. BV scales are a useful tool in putting together a complete protein

[D&G]

He is mistaken - do you take the word of Big Cat over Lyle McDonald????? - countless articles on the web point out the single study that showed that was due to an error made by the scientist. Read the article by Lyle McDonald - he is just about THE most knowledgable person in the world on the subject of bodybuilding nutrition - It still comes down to simple maths - YOU CAN'T RETAIN MORE THAN YOU WERE GIVEN IN THE FIRST PLACE!!

Here is an article for you -

Biological Value (BV): This system determines the amount of nitrogen retained by the body after absorption. The problem is that the whole system was based on the assumption that egg was the only source capable of hitting the maximum score possible of 100. Wait a minute, - the maximum score of 100? What about all those products we read about with a BV in excess of 150? This is perhaps the scoring system that is most open to abuse, with companies intentionally manipulating the figures for marketing purposes or unintentionally confusing BV with another scoring method. Indeed, nutrition expert, Jerry Brainum, recently pointed out in IRONMAN Magazine that in a study where the BV of whey was listed as 157, the author confused BV with chemical score! Chemical score compares the amino acid profile of an ideal reference protein to a test protein. This system allows for scores over 100 and, in fact, whey scored 157. However, one particular British company has sunk even lower by inventing its own BV chart for its advertisements, where it comes up with a whole bunch of fictitious figures that include a score of 77 for micellar casein. This is a clear example of intentional deception, as it was calcium caseinate that was assessed under the BV system, not micellar casein. Just like old King Canute trying to hold back the tide, this particular company responded to the latest scientific revelation that only micellar casein has anticatabolic properties by irresponsibly trying to mislead the public. As any scientific journal will tell you (e.g. Advanced Nutrition and Human Metabolism), it is impossible to have a BV in excess of 100; this is the maximum score that the system makes an allowance for.

I will gladly point out Big Cat's mistake to him - he has obviously got the info from an unreliable source

[Travis Stenersn]

Hmm, I've always read that the definition for BV was the definition you used for 'chemical score'
Where can I read this article by Lyle Mcdonald?

[Travis Stenersn]

To everyone who thinks Soy is so great, here is some reading:

http://www.testosterone.net/articles/154jump.html
http://www.testosterone.net/html/body_87prote.html
http://www.testosterone.net/html/body_143soy.html

Here's a study:
"Diets with protein of inferior quality may increase protein breakdown in skeletal muscle but the experimental results are inconsistent. To elucidate the relationship, pigs were fed isoenergetic and isonitrogenous diets based on soyabean-protein isolate or casein for 15 weeks, with four to six animals per group. A higher plasma level of urea (2.5-fold the casein group value, P = 0.01), higher urinary N excretion (2.1-fold the casein group value, P = 0.01), a postabsorptive rise in the plasma levels of urea, 3-methylhistidine and isoleucine in soyabean protein-fed pigs suggested recruitment of circulatory amino acids by protein breakdown in peripheral tissues.

Significant differences between dietary groups were detected in lyso****l and ATP-dependent proteolytic activities in the semimembranosus muscle of food-deprived pigs. A higher concentration of cathepsin B protein was found, corresponding to a rise in the cathepsin B activity, in response to dietary soyabean protein. Muscle ATP-stimulated proteolytical activity was 1.6-fold the casein group value (P = 0.03). A transient rise in the level of cortisol (2.9-times the casein group value, P = 0.02) occurred in the postprandial phase only in the soyabean group.

These data suggest that the inferior quality of dietary soyabean protein induces hormonally-mediated upregulation of muscle protein breakdown for recruitment of circulatory amino acids in a postabsorptive state."

Br J Nutr 2001 Apr;85(4):447-57 Activation of skeletal muscle protein breakdown following consumption of soyabean protein in pigs. Lohrke B, Saggau E, Schadereit R, Beyer M, Bellmann O, Kuhla S, Hagemeister

H. Research Institute for Biology of Farm Animals,

Dummerstorf-Rostock, Department of Animal Nutrition, Germany.



Take home message is to NOT rely on soy as your major source of protein.

[ex_banana-eater]

hahaha i wonder what "atp-dependant" excercises they were making these pigs do

[D&G]

This is the article guys - its a 4-parter and very comprehensive - I guarantee you will learn a lot from it!

http://www.thinkmuscle.com/articles/...protein-01.htm

I will PM Big Cat and point out the innacuracy in his article

[Travis Stenersn]

The semimembranosus is part of the hamstring group, it was probably hip extension.

[ex_banana-eater]

my final result is that i will buy some soy protein and have a scoop or two every other day before i go to bed.

thanks for the help guys

[Jean Schernoff]

You guys follow BV? I only look up to PDCAA.

And soy protein has a BV of 59, not 159.

Travis, the most obvious way to determine the quality of a given protein is to break it down into it's individual amino acids. This amino acid profile is then compared to a standard profile. Egg protein is the standard that is used in a Chemical Scoring scale for protein quality and has a rating of 100. Take for example a protein that has a limited amount of a specific amino acid. This amount is then com-pared to the amount found in egg protein. If the amount in the test protein is 75% of that found in egg then the test protein gets a rating of 75. From this you would assume that if you could feed a person an amount of this protein that is exactly his requirement, you would see nitrogen excreted in the urine in the amount of 25 percent of the nitrogen fed.

BV is not CS, but somehow is related to PDCAA.

[Travis Stenersn]

I agree with you Jean that the Protein Digestibility Corrected Amino Acid score is a better judge of protein quality, as it takes into account the missing aminos according to what is necessary for humans.


Jean did you read D&G's exert from the website there.. the one about BV? What did you think of it? Have you heard of BV being a measure of nitrogen retention before?

[Jean Schernoff]

I'll read it right now. Thanks for reminding. If you got questions about scales of protein, ask. I will be glad to help you with them.

[Jean Schernoff]

Oh yeah,

There was a study on this, I'll tell you what was saved in my head.

When measuring the BV of a protein source, two nitrogen studies are done. The first study determines how much nitrogen is lost from the body even when no protein is fed. This amount of nitrogen loss is assumed to be inevitable and that the body will naturally lose it regardless of the amount of nitrogen in the diet. In the second study an amount of the protein is fed that is slightly below what is required. As before, the nitrogen losses are then measured, but this time they are compared to the amount of nitrogen consumed.

To determine the actual BV of the protein the results are then derived using this formula:

(N retained / N intake) x 100

[MartialArtist]

I find soy to be a healthy complement. I don't take any supplements, but I eat soy-rich foods and any health nutritionist would tell you that eating chicken and beef all the time isn't healthy.

If you want to get supplements, I find whey to be way too expensive