cron-web.org

[A1CR]

What is good nutrition anyway? (was RE: Excess Weight Associated With Better Survival in Veterans)

All:

>> >>--- CRONie_NB wrote:

>> >>Far and away the biggest weakness of the CR
>> >>Society is
>>> >>>not only do we under emphasize this we do not even
>>> >>>have a clue as to what optimal nutrition is.

> > The Lady of the Triumph of Light replied:
>> >>I'm not sure where this is coming from. We are
>> >>constantly bugging people to get nutritional
>> >>software
>> >>so that they actually know if they're meeting their
>> >>nutritional needs ... We talk constantly about the
>> >>relative merits of different macronutrient ratios,
>> >>and of different kinds of diets. While we disagree --
>> >>and reasonable, informed people can disagree about
>> >>these issues -- we definitely don't underemphasize them.

>> >> While we may still believe,
>> >>based on the animal evidence, that improving
>> >>nutrition without reducing calories won't lead to
>> >>extended lifespans, that doesn't mean that we don't
>> >>do everything possible to get the best nutrition we
>> >>can, based on the information we have. Both Walford's
>> >>books and Brian and Lisa's book make it very clear
>> >>that you can't neglect nutrition and live longer.

CRONie_NB again:
> > We agree to disagree I suppose. Here are the problems
> > I see:

Your response MOSTLY amounts to saying that "our" beliefs about
nutritioin may be mistaken and/or that the Society fails to make
official reccomendations about specific details of nutrition. Thus, you
mostly seem to be missing the thrust of the critique being made by the
Priestess of the Silver Star, who wasn't arguing this point. You had
said that the Society *underemphasizes* nutrition, and that "we do not
even have a clue as to what optimal nutrition is" -- which She rightly
indicates just doesn't reflect the actual content of the Archives, the
popular books, or the CRS info (How To Guide, etc).

These resources, as She says, put nutritioin exactly the right level of
emphasis, reminding all that CR won't work if you're going to be
malnourished, and debating what might be optimal, but ultimately
attempting to remain cognizant of the key points, which are that (a) the
minor issues that we debate under the heaading of "optimality" are in
fact mere tweaks to a few well-established nutritioinal principles to
which almost everyone, from the IOM to the FDA to Atkins to Ornish,
assents; and (b) that CR, with merely *adequate* nutrition, is the most
powerful method of preserving youth and health known, and retards
biological aging. Within the confines of these two guidelines, any
further fine-tuning is not going to have any dramatic impact one way or the
other, as the studies clearly show.

Now, on a few specific points:
> >
> > 1. We assume the US Govt. recommendations are
> > accurate. Measuring something accurately that may be
> > inaccurate is of little value.

Clearly, "we" make no such assumption: US gov't reccs are debated
endlessly on the List. That said, broadly speaking, MOST gov't reccs
are perfectly appropriate, esp for the AL populace to which they are
primarily addressed -- and I for one don't ASSUME this, but have worked
my way thru' the literature underlying them. If anything, there is a
large (but fortunately shrinking) constituency whose knee-jerk reaction
is assume that everything that Authority says about nutrition is wrong,
and in particular that the RDAs are orders of magnitude too low; these
opinions are largely based in ignorance, by folks who have been
convinced by sloppy arguments, mostly advanced by supplement pushers (I
speak as a notorious, but hopefully relatively intellectually honest and
sophisticated, supplement pusher ), and who have NOT read the
enormous and normally quite well-presented arguments underlying them.
For those interested, the mammoth tomes that summarize the evidence
underlying the IOM's current RDAs are available gratis online here:

http://www.nap.edu/catalog/dri/

(Click on the photo of a given volume, and then scroll down to read the
individual chapters; you have to go page-by-page, alas).
> >
> > 2. We can not come to a conclusion on protein intake.
> > Is it or is it not bad to consume higher protein
> > diets?

It's good, as any sophisticated reading of the evidence would show, of
course . But while the suggestioins of combinig protein RESTRICTION
with CR are nucking futz, whether one gets 1, 1.5, or more RDAs of
protein is really a beta issue.
> >
> > 3. We make no modifications in nutritional
> > recommendations depending on individual needs based on
> > their genes and environment.

Of course we do: we bring up this stuff all the time on the List and in
our resources. You cite an example yourself:

> > Zinc also tends to run low in Cronies so
> > we probably need more zinc than most people.

... and plenty of others could be cited -- and have been.

> > 4. We sometimes ignore published data. For example,
> > taking a daily multivitamin has been shown to decrease
> > life span.

Where has this been shown in normal, healthy nonsmokers?

> > 5. The role of dairy is questionable - good or bad?

Tweaking. Varies with genes and environment . Good, for most. Next?
> >
> > 6. Most importantly we have not established if a CR
> > diet requires modifications in nutrient
> > recommendations.

I partially agree with you here. On the one hand, we in fact DO know
that a CR diet requires modifications in nutrient recommendations; you
rightly cite the example of zinc, and others have been documented on the
List (protein, Fe, Cu, Ca needs are increased; OTOH, CR protects
against effects of some deficiencies: B1, Mg, Cu). Indeed, I thought
that these were on the How To Guide, and am surprised to see that
they're not. [Check here: http://www.cron-web.org/supplements-guide-1.html]

Vitamin D was recently suggested based on highly speculative
argumentation, but there is actually some better (albeit still limited)
evidence (1,2); also note that, contrary to what was previously
reported, vitamin D synthesis and etabolism occurs in the skin and
kidneys, not in adipose tissue per se (tho' the vitamin is STORED
there). IAC, the problems observed occur in rats getting the biochemical
minimum and in free-living humans among whom deficiency is already
endemic; any negative influence of CR is unlikely to amount to much if a
person is taking 1000 IU of D3/d as s/he should. (Fortunately, anyone
with any damned sense gets blood tests at least annually, and can have
this checked in the dead of winter).

All that said, we pro'ly oughta mention it.

OTOH: again, it's clear from the rodent data that rodent "DRI" is quite
adequate, *in combination with CR*, to elicit a powerful anti-aging
effect; further changes are again unlikely to lead to any dramataic
benefit, and failure to implement same is unlikely to have much negative
impact.

> > A lot of this stuff is scattered here and there in the
> > archives but we need to compile it, evaluate it and
> > make some recommendations.

There are a very few cases where I agree (again, Zn, protein, Ca, Fe),
but for the most part, we oughtn't to make any such reccs, because the
evidence is often inconclusive and because it's almost entirely going to
be mere tweaking. If people just did this:

http://www.calorierestriction.org/Getting_started

... using nutritional software and a scale to control Calories and
DRI-level specific nutrient guidelines (with a few minor modifications),
the rest could safely be ignored.

Oh, and speaking of using nutritional software and a scale: hello, CRONie_DM!

CRONie_DM wrote:

> > Would also add that even careful weighing and analyzing of the food
you eat
> > is far from accurate. Some examples: Mineral content of food differs by
> > region, but the USDA database is merely an average of a few samples.
> > Bioavailability of specific nutrients is pretty much a mystery and
depends
> > on raw vs. cooked vs. overcooked, fresh vs. frozen, what other foods
(like
> > fiber) are present, and personal factors like quality of gut
bacteria, food
> > allergies, and even stress. Same problems apply to total calories
consumed.
> >
> > This doesn't mean you shouldn't analyze what they're eating, but
recognize
> > that the numbers you get are ball park figures.

Again, all of this grossly overestimates the level of uncertainty. Fo
commonly-eaten foods especially, the USDA database typically has several
or even many independent samples from different locales, and can
sometimes even break down by region of harvest (see eg citrus fruit) and
time of year (eg tomatoes). Picking "broccoli, raw" as an archetypal CR
food, I see that there are at least 12 data points for any nutrient of
importance (as vs eg the starch or galactose content) to the intake of
which broccoli would actually be a isgnificant source (as vs eg
individual fatty acids), and >23 for nearly all and 33 for many. And the
differences, as can be seen by looking at actual entries, rarely exceed
about 10% -- and precisely because these come from multiple samples,
that's all going to average out in the wash.

To suggest that this is just 'ball park figures' is really very
misleading; and more importantly, one must contrast this strategy with
the alternative, which is to 'eat a healthy diet containing a wide
variety of foods' (or some other Dep't of Agriculture pap) and just TAKE
IT ON FAITH that one is getting good nutrition.

I know from personal experience, from List anecdotes, and from
large-scale studies like NHANES that it is quite easy to eat a 'healthy'
diet and still run into deficiencies (or toxic excesses) on specific
nutrients, and overwhelmingly these wouild not have happened with a
combination of education and software + a scale; and again, what is the
alternative strategy?

> > Your software may spit out
> > decimal values, but that's a bunch of baloney. For many nutrients, you're
> > lucky if the order of magnitude is correct.

CRONie_DM, I'm sorry, but THAT is simply rubbish. "An order of magnitude"??
Again, you won't find many nutrients out by more than about 10% on large
sample sizes -- and again, in a modern food distribution system we get
our broccoli from California one week and Mexico the next, so that
(unlike when one consistently got it from one's neighbor's fields) thsi
kind of thing really will average out.

> > Some things I think most of us would agree on: Eat a diet high in
vegetables
> > and fruit and low in high-glycemic carbohydrates and saturated fat. Monitor your
> > health carefully to make sure your diet is working for you.

Amen -- as far as it goes. That's the big picture in an AL population.
Again, aside from Atkins' equivocatioin on SFA, almost any professional
dispenser of nutritional advice not wrapping hir gametes in tinfoil
would agree with this. For a restrictive and highly experimental diet
like CR, safety demands a lot more precisioin, and clearly software +
scales are the best way to get it.


1: Cifuentes M, Morano AB, Chowdhury HA, Shapses SA.
Energy restriction reduces fractional calcium absorption in mature
obese and
lean rats.
J Nutr. 2002 Sep;132(9):2660-6.
PMID: 12221226 [PubMed - indexed for MEDLINE]

2: Lemann J Jr, Gray RW, Maierhofer WJ, Adams ND.
Effects of weight loss on serum 1,25-(OH)2-vitamin D concentrations in
adults:
a preliminary report.
Calcif Tissue Int. 1984 Mar;36(2):139-44.
PMID: 6430497 [PubMed - indexed for MEDLINE]