Thread: Looking for 100% natural soy protein....

Why?

Soy has a poor amino profile and has a BV barely above 50%. If you are vegan though I wish you luck finding what you are looking for.

Some places to try:

www.1fast400.com
www.nutritionexpress.com

Doesn't soy protein promote estrogen production too?

Yes.

Originally Posted by SlimShady

Doesn't soy protein promote estrogen production too?

No. Unless you eat tons of it, and not much else.

From what I've learned it seems that Whey is much better then Soy. The BV value is higher and BCAAs are way up there also. Then you take into account protein utilization and it makes perfect sense to use Whey instead of Soy. But if your looking to stay away from animal products then Soy is it for you. I think that you will find that most body builders prefer Whey.

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For years, casein has been the "gold standard" of protein quality, and most experimental researchers still prepare casein-based diets for their animal studies. But as it turns out, whey protein is much superior to casein in terms of protein quality. There are various techniques for measuring protein quality but suffice it to say that four methods are commonly used: protein efficiency ratio (PER), biological value (BV), net protein utilization (NPU), and chemical score. Regardless of which technique is used, whey always scores better than does casein, as shown in Table 1. Whey is also far superior to soy and other lower quality proteins such as rice, beef, and wheat (which are similar to soy protein).
Whey and egg are, for the most part, comparable, and are the two best dietary sources of protein. Whey has a higher BV than does egg, which is important, since BV reflects actual protein utilization in adults. In contrast, PER is a measure of the growth rate of young animals, which is less pertinent to the situation in adults (the higher PER of egg is due to its higher content of sulfur-containing amino acids, which are especially important during growth). From the standpoint of exercise physiology, the main difference between whey and egg is that whey contains higher levels of BCAAs, which makes whey a better protein source for athletes and bodybuilders.

Table 1:
A COMPARISON OF WHEY, CASEIN, EGG, AND SOY 1'2
Protein...PER...BV.....NPU.....Chemical Score
Whey.....3.0....104...92........>100
Casein...2.5.....71.....76........82
Egg........3.9....100....94.......>100
Soy........2.2.....74.....61........69

There are three important attributes of whey protein which make it an ideal source of protein for athletes and body-builders. First, whey is very high quality protein, and is hence important in maintaining muscle structure and function during periods of strenuous exertion. High levels of high quality protein exert an "anti-catabolic" effect, meaning that muscle breakdown is prevented.
In addition, whey protein is one of the richest sources of BCAAs, which play a central role in muscular function. BCAAs (notably leucine) are known to be directly oxidized in muscle, thereby acting as a source of energy. In addition, leucine is used for alanine synthesis in muscle; alanine is subsequently transported to the liver and used to make glucose, which is then available as a fuel for muscular contraction. The high content of BCAAs in whey strongly support its use by athletes and bodybuilders alike.
Finally, recent studies have shown that lactalbumin (the main protein in whey) can enhance immunity in animals. In one study by Bounous and colleagues, mice were fed diets containing various proteins at a level of 20 percent.3 After eight weeks of dietary treatment, the animal's immune system was assessed using a standard assay (the plaque-forming cell response in spleen). Lactalbumin proved to be 2.4 times better than egg protein, and five times better than casein with regard to immunoenhancement! The stimulatory effect of lactalbumin was apparent at two weeks and persisted throughout the course of the study. More importantly, the immuno-stimulating effect was observed when lactalbumin was replaced by an amino acid mixture duplicating its amino acid pattern. This firmly demonstrates that the amino acid composition of lactalbumin is responsible for its enhancing effects in the immune system. The significance here is that strenuous exercise has recently been linked to a depression in both the cellular and humoral immune responses of adult humans.4 Hence, athletes and bodybuilders alike might be wise to use whey (lactalbumin) as their source of dietary protein.

Soy Protein

Originally Posted by mit37

I made a post in the supplements section but I guess it belongs here also...I was looking for soy protein 100% natural and was wondering whats a decent brand and a good place to shop online for such things...thanx for all the help.

Gosh - once someone starts a rumour it seems to just 'stick around' like a bad smell.

1. Soy proteins are NOT oestrogenic. Most have been processed so the phyto-oestrogens have been removed and it is this that is the active compound. Also, the oestrogenic effect of these phyto-oestrogens is NOT as active as everyone thinks. Infact, it can actually be ANTI-OESTROGENIC in it's activity - it can bind to oestrogen receptors and stop your natural oestrogen from binding - as your natural oestrogen is more powerful this DECREASES the activity of oestrogens in your body.


2. Soy isolates actually have good/comparable biological values and conversion scores.



In my opinion, as part of a good diet, they are fine protein to use as another protein source - especially the unflavoured types as they are very useful in cooking.


Anyway - some articles if anyone is interested:
Animal v's vegetable
Protein evaluation

And some discussions on AL:

here
And Here

Originally Posted by Ex_banana-eater,Nov 10 2003, 06:15 PM

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. loehrke@fbn-dummerstorf.de.

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 lysosomal 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

Originally Posted by shpongled

I'm starting to think it's time to ditch the soy

David knows best. Better safe than sorry

This was a good read also http://www.brinkzone.com/soy.html

The reason I was going to try out soy protein is because, regular whey protein shakes have been killing my digestive system...it hasnt been sitting well...so I guess I wanted to try out some other type of protein....

Originally Posted by mit37

The reason I was going to try out soy protein is because, regular whey protein shakes have been killing my digestive system...it hasnt been sitting well...so I guess I wanted to try out some other type of protein....

www.allthewhey.com

You can get egg, milk and other types. Soy is not good dude