cron-web.org

[MR]

Subject:
RE: Body fat mediates insulin sensitivity in CR rhesus monkeys; Plasma glucose levels do *not* fall in CRed rhesus

"CRON4healthyfuture " wrote:
> >
> > Here is a rhesus CR study in the same journal that Barja recently fell on
> > his face in.

This statement is, of course, not only gratuitous (as of no particular
relevance to this paper or the subject at hand), but also without
foundation, as I've already indicated and as the full text of the paper
to which you refer (posted in full by A CRONie) makes clear. The attack
mounted against Barja around this paper consisted entirely of missing
the point, ignoring the evidence external to the paper, and engaging in
pointless sarcastic-sounding but substantively void invective and naked
ad hominem attacks.
> >

> > I think that this almost a "step backwards" for CR research, because it
> > suggests that body fat is the only important determinant of insulin-
> > sensitivity.

CRON4healthyfuture, where do you get this from? The abstract says that "Body fat in
part statistically mediated the effect of DR to enhance insulin
sensitivity indices", and again that "The observed insulin sensitivity
indices from all models, elevated among R vs. C monkeys, may be
explained at least in part by the difference in body fat". That's quite
uncontroversial, and it's a typical caricature to summarize this as
indicating that reduced body fat is the ONLY important determinant in
these reports.

> > If this is the case, then liposuction and exercise should be
> > shown to be equivalent to CR.

This, again, is totally unreasonable. Even if the paper found that body
fat is the only important determinant of insulin sensitivity (which it
did not), that would still be far from a demonstration that liposuction
and exercise were equivalent to CR.

I'm very tired of hearing that because X does Y, and CR does Y, that X
is the same as CR. I'm even more tired of being told that because CR
does Y, and X does Y even more so, that X is actually even BETTER than
CR on a global basis. And I am ESPECIALLY tired of hearing this latter
claimed in cases where studies have already been performed to test such
an idea, and the findings either weigh against, flatly refute, the thesis.

-MR

> > 1. Am J Physiol Regul Integr Comp Physiol. 2003 Jul 3 [Epub ahead of print].
> > Related Articles, Links
> >
> > Insulin sensitivity and glucose effectivenes from three minimal models:
> > Effects of energy restriction and body fat in adult male rhesus monkeys.
> >
> > Gresl TA, Colman RJ, Havighurst TC, Byerley LO, Allison DB, Schoeller DA,
> > Kemnitz JW.

> > PMID: 12842866 [PubMed - as supplied by publisher]

2.