Marilyn wrote: 
> ...is it (external betacellulin in the blood) necessarily an indicator 
> of potenial carcinogenesis?

Maybe, maybe not. The research is suggestive, but not yet conclusive. I
don't think I would make a decision on dairy based solely on this research.
I would weigh the overall evidence. You could also read the arguments of
Audette/Cordain vs. Fallon/Enig. Cordain's articles and Website provide
numerous citations of sources that you can look up. Fallon/Enig don't tend
to provide many references (other than Weston Price's research), so you'll
have to do more of your own searching for research that is pro dairy.
Fallon/Enig recommend raw dairy, but most research is on pasteurized dairy
(since it is illegal to market raw dairy in most states).

Other than the observations of traditional pastoral peoples by Price and
others and Pottenger's cat study, I haven't seen much research that
concluded that raw dairy is healthy, so if you find any other positive
studies on it please do share them with us.

> Does the body exert a tight control over betacelulin levels in the 
> blood and normalize them?

The following report does suggest that hormones may regulate betacellulin.
How much human hormones may compensate for consumption of bovine
betacellulin has not been studied, as far as I know. So, at best, consuming
bovine dairy products is currently a roll of the dice.

<<Measurement of betacellulin levels in bovine serum, colostrum and milk 
S E P Bastian, A J Dunbar, I K Priebe, P C Owens and C Goddard Cooperative
Research Centre for Tissue Growth and Repair, Australia 
http://joe.endocrinology-journals.org/cgi/reprint/168/1/203.pdf

The observation that only 27% of the female animals contained detectable
serum betacellulin levels, may indicate that betacellulin could be under
control of hormones that regulate oestrus. Studies of EGF blood levels in
other species have also reported effects of ontogeny and gender (Perheentupa
et al. 1985). Our findings show that significant levels of betacellulin are
present in FBS and that betacellulin is also contained in bovine colostrum,
mature milk and cheddar cheese whey. ...

Expression of receptors for betacellulin has been documented in a diverse
variety of cell types in several animal species in foetal and neonatal life.
These findings lend credence to the hypothesis that betacellulin may be a
modulator of foetal and neonatal growth and development. The true
significance of betacellulin in bovine milk and foetal serum and the
regulation of betacellulin in adult serum require further study.>>


Adrienne wrote: 
> Since betacelullin is a hormone -- does anyone know if it would be 
> found primarily in the dairy fat?

The above referenced report says that betacullulin is found in bovine serum,
colostrum, milk and cheese whey. There is not specific mention of fat, but
given that it is in cow blood and colostrum (which is low fat) it sounds
like it is probably not restricted to the fat in milk, if it is in the fat
at all.

DS wrote: 
> Is Kefir any safer than the rest of the dairy items?

The reports suggest that fermenting milk wouldn't have a significant effect
on betacellulin (or casein and whey, which some people are intolerant of or
allergic to), but it does break down some of the lactose...

ScienceDaily: Kefir May Bolster Lactose Tolerance In Intolerant People
www.sciencedaily.com/releases/2003/05/030530081555.htm 
"Participants in the current study reported having little or no symptoms
associated with lactose intolerance after eating ... yogurt and kefir. ..."