If you've ever entertained the idea of using a colostrum supplement for bodybuilding purposes, you might find what I'm about to share interesting, and hopefully useful.
If you have used a colostrum supplement in an effort to enhance body composition, please share your experiences --bad, good or indifferent!
I warn you that I'm not the sharpest tool in the shed on the subject of colostrum (nor anything in particular), but I have learned some interesting things from research scientists that are.
Milk, as most of you know, is a mixture of two major proteins, whey and casein. Colostrum, or 'first milk', is produced by mammals in the first 1-4 days of nursing. In cows, colostrum is produced up to about the 6th milking.
Think of colostrum as milk with a built-in 'pharmacy'. Colostrum is teaming with microbe-fighting, tissue-building factors, all ready to go to work on the immature, and desperately dependent infant animal.
Frequently, milk proteins are separated and sold as individual supplements (e.g., whey protein isolate).
Not surprisingly, however, research is beginning to suggest that leaving casein and whey together (i.e., as nature gives them to us) may offer superior benefits. (Again, I say "may", as I'm to a certain extent theorizing here.). Casein seems to be especially important in this regard.
Whey is commonly described as a ‘fast’ protein, meaning it is quickly digested and absorbed. Casein is considered ‘slow’ by comparison. Thus, popular in the bodybuilding community is the notion that combining whey and casein will offer rapid, yet sustained delivery of amino acids to the body's tissues (e.g., your muscles).
Interestingly enough, however, the differences between casein and whey in terms of amino acid absorption seem to disappear within the context of a mixed meal. Furthermore, when it comes to digestion and absorption, it could be argued that faster is not necessarily better ---quite the contrary, in fact.
Whey protein tends to 'dump' into the small intestine relatively more quickly than does casein. This is associated with a more rapid exposure ot the intestinal cells to the products of its digestion (peptides, amino acids), resulting in a faster rate of absorption of amino acids into the bloodstream.
Unfortunately, protein synthesis (as in muscle) occurs at a snail's pace compared to the rapid rate at which whey's amino acids enter the bloodstream. That is, the amino acids are absorbed faster than your muscles' protein-building machinery can make efficient use of them.
In addition, high levels of certain amino acids can be toxic to your tissues. Thus, much of whey's rapidly absorbed amino acids are accordingly 'burned up', or oxidized, so as to clear them out of the bloodstream. The oxidation of amino acids occurs in preference to that of fat. Thus, rapidly absorped proteins, such as whey, may be expected to suppress the burning of fat and promote fat gain (arguably not an issue, of course, unless you're consuming too many calories).
In short, the faster your protein supplement is absorbed into your bloodstream as amino acids, the more likely those amino acids are to be 'wasted' (oxidized) rather than channeled into the building of new tissue (e.g., muscle) proteins. Hmm...
Nevertheless, combining casein with whey, as well as other protein supplements, such as casein, may offer some benefits.
Colostrum contains a plethora of biologically active components beyond its protein contents. These include growth factors like insulin-like growth factor-I (IGF-I). IGF-I, a 'messenger' of growth hormone (GH), has long been worshipped by bodybuilders as a muscle-enhancing molecule to be reckoned with.
I have long questioned whether colostrum holds any utility for bodybuilders like myself who 'simply' wish to pack on muscle tissue in the absence of additional (or alongside a concomitant reduction in) body fat.
Animal studies seem to suggest that colostrum's growth factors exert their effects largely at the intestinal level (e.g., supporting the growth of intestinal tissue), though not entirely so.
Then there is the question of the bioavailability of colostrum's IGF-I in the adult human: Can it get into the bloodstream and thence the muscles so as to enhance muscle growth?
In terms of its electrical character, IGF-I is a basic protein. Thus, it's pretty happy (stable) in the acid environment of your gut. But when it gets into the intestine, protein-digesting enzymes can cleave it into pieces, rendering it biologically inactive (i.e., now a mere source of amino acids).
This brings us back to casein. Casein appears to be capable of protecting biologically active proteins by extending their life time in the intestine. This may extend to biologically active proteins in the colostrum supplements, and possibly whey, that you now see on the retain shelf....or maybe not. Controlled experiments will determine this, perhaps.
Casein has been shown to increase the half-life of IGF-I in the upper part of the small intestine (duodenum) from 2 to > 30 minutes (similar to its half-life in serum), with 80% of duodental IGF-I still intact after 60 minutes. The same effect of casein is seen with epidermal growth factor (EGF), a related peptide.
Will combining casein with colostrum allow IGF-I to get into your bloodstream and treat your body to a muscle-building and/or fat-reducing delight? That's highly questionable, but possible.
Keep in mind, too, that local IGF-I production, i.e., that which occurs right inside your muscles themselves, seems to play the most important role in building bigger muscles. The IGF-I that floats about in your blood stream seems of lesser importance.
Thus, even if a casein-rich product containing IGF-I from colostrum did manage to affect an increase in blood IGF-I levels, it might not affect intramuscular IGF-I levels sufficiently to trigger growth of this tissue. And perhaps IGF-I that isn't "asked for", i.e., as through pumping iron (which can increase muscle production of IGF-I and its associated receptor) isn't all that useful anyways.
Just some thoughts.
To tidy this mess of ideas up for you, casein seems to protect biologically active proteins, such as those found in colostrum (and possibly whey) from destruction/inactivation in the intestine. Thus, adding casein to such products (or leaving milk intact) may be a good thing for your physical apperance and overall health.
Please send me your comments and/or questions. If you've had experiences with colostrum before, particularly in regards to body composition, please do share.
I really appreciate your attention and continued interest!