Some interesting posts. Getting subjects for such a study appears to be almost as difficult as it is for certain Ph 2 oncology trials ..... Yes, all such papers should end with "Further research involving larger sample sizes is necessary to confirm and extend the findings presented here ... yada yada yada".
Casein is a family of phosphoproteins found in high levels in milk, proteins that are unrelated structurally to IGF-1 (at least as far as I know). Someone please provide actual data on the IGF-1 content of "casein", with details on purity and methods of analysis. That would be helpful.
Wiki gives a reference to a paper on dietary proteins (including casein) as elevating IGF-1 mRNA expression in rat liver (see below). This is an entirely different matter of course, not relevant to the current regulation. The issue Vijay faces is administration of banned substances, not compounds or formulations that elevate endogenous levels of banned substances.
Miura, Y et al. Effect of dietary proteins on insulin-like growth factor-1 (IGF-1) messenger ribonucleic acid content in rat liver. Br. J. Nutrition 67:257, 2007.
Vijay might also point out that rats are not competitive on the PGA tour, though some ex-wives may differ :)
It actually is relevant if you think about the current list of banned substances. Consider the case of erythropoietin. Just like casein, it does nothing by itself other than to increase the body's own production of endogenous substances. Erythropoietin contains nothing that enhances performance in and of itself. But it stimulate the marrow to bump up production of hemoglobin which then leads to the increase in performance/endurance.
The question is, is an increased level of IGF-1 a boost to performance. If it is, then any compound which endogenously raises the levels of IGF-1 in the body should also be considered a performance enhancing compound.