Re: 10% CR increases longevity even when started in adulthood.

[Guest guest]

This is hard to " swallow " - pardon the pun. Am I to understand that one can

eat ice cream sundaes only (or substitute your favorite forbidden food) ,

and it will have no effect on life span?

on 5/18/2005 10:11 AM, citpeks at citpeks@... wrote:

> Diet composition had no effect on life span

[Guest guest]

Thanks, Tony,

That looks good for the question about losing weight.

Of course, I started later than 1/3 of lifespan (64).

Regards.

----- Original Message -----

From: citpeks

Sent: Wednesday, May 18, 2005 9:11 AM

Subject: [ ] 10% CR increases longevity even when started in adulthood.

.... and macronutrient composition doesn't seem to matter. Al Paterfound this abstract.==============Obes Res. 2005 Apr;13(4):693-702. Intentional weight loss reduces mortality rate in a rodent modelof dietary obesity. Vasselli JR, Weindruch R, Heymsfield SB, Pi-Sunyer FX, Boozer CN,Yi N, Wang C, Pietrobelli A, DB. Department of Biostatistics, University of Alabama, Ryals PublicHealth Building, Room 327, 1665 University Boulevard, Birmingham,Alabama 35294-0022. Dallison@.... OBJECTIVE: We used a rodent model of dietary obesity to evaluateeffects of caloric restriction-induced weight loss on mortality rate.Research Measures and Procedures: In a randomized parallel-groupsdesign, 312 outbred Sprague-Dawley rats (one-half males) were assignedat age 10 weeks to one of three diets: low fat (LF; 18.7% calories asfat) with caloric intake adjusted to maintain body weight 10% belowthat for ad libitum (AL)-fed rat food, high fat (HF; 45% calories asfat) fed at the same level, or HF fed AL. At age 46 weeks, thelightest one-third of the AL group was discarded to ensure a moreobese group; the remaining animals were randomly assigned to one ofthree diets: HF-AL, HF with energy restricted to produce body weightsof animals restricted on the HF diet throughout life, or LF withenergy restricted to produce the body weights of animals restricted onthe LF diet throughout life. Life span, body weight, and leptin levelswere measured. RESULTS: Animals restricted throughout life lived thelongest (p < 0.001). Life span was not different among animals thathad been obese and then lost weight and animals that had been nonobesethroughout life (p = 0.18). Animals that were obese and lost weightlived substantially longer than animals that remained obese throughoutlife (p = 0.002). Diet composition had no effect on life span (p =0.52). DISCUSSION: Weight loss after the onset of obesity duringadulthood leads to a substantial increase in longevity in rats. PMID: 15897478

[Guest guest]

Hi Francesca:

Clearly the fat issue is entirely different in rats. Rats, as I

understand it, do not die of heart disease, which is overwhelmingly

the most major issue regarding fats with humans.

Rats and mice almost all die of cancer. (I know this is true of

mice. I do not guarantee it is true of rats. Can anyone confirm

this?)

If true (in rats) then clearly the results of this experiment are not

totally transferrable to humans. Now perhaps a high fat diet with

only healthy fats (are there any?) would be OK in humans.

We have yet to see, as far as I know, experiments on organisms that

suffer heart disease like humans, where each group was fed large

amounts of a single fat (palmitic, or oleic, or myristic, or lauric,

etc.) to determine for sure the effects of each fat molecule.

Until I see such data I will be restricting almost all fat types.

That includes oleic, until we have at least two studies that

contradict the results of that recent Crete study which showed oleic

to be atherogenic.

Fortunately CR seems to solve this problem. So for us perhaps the

fat issue is not so important.

But we all have to make our own decisions on this stuff with evidence

that is still a very long way from definitive.

Rodney.

>

> > Diet composition had no effect on life span

[Guest guest]

Hi Tony:

" Life span was not different among animals that had been obese and

then lost weight and animals that had been nonobese throughout life

(p = 0.18). "

This is very interesting. And enormously encouraging for people who

are substantially overweight right now, or have been years ago. But

I am not sure that that study shows that those who have been

overweight can gain 100% of the benefits of real CR (i.e. CR of more

than modest restriction).

Rodney.

> ... and macronutrient composition doesn't seem to matter. Al Pater

> found this abstract.

>

> ==============

> Obes Res. 2005 Apr;13(4):693-702.

> Intentional weight loss reduces mortality rate in a rodent model

> of dietary obesity.

> Vasselli JR, Weindruch R, Heymsfield SB, Pi-Sunyer FX, Boozer

CN,

> Yi N, Wang C, Pietrobelli A, DB.

> Department of Biostatistics, University of Alabama, Ryals Public

> Health Building, Room 327, 1665 University Boulevard, Birmingham,

> Alabama 35294-0022. Dallison@m...

>

> OBJECTIVE: We used a rodent model of dietary obesity to evaluate

> effects of caloric restriction-induced weight loss on mortality

rate.

> Research Measures and Procedures: In a randomized parallel-groups

> design, 312 outbred Sprague-Dawley rats (one-half males) were

assigned

> at age 10 weeks to one of three diets: low fat (LF; 18.7% calories

as

> fat) with caloric intake adjusted to maintain body weight 10% below

> that for ad libitum (AL)-fed rat food, high fat (HF; 45% calories as

> fat) fed at the same level, or HF fed AL. At age 46 weeks, the

> lightest one-third of the AL group was discarded to ensure a more

> obese group; the remaining animals were randomly assigned to one of

> three diets: HF-AL, HF with energy restricted to produce body

weights

> of animals restricted on the HF diet throughout life, or LF with

> energy restricted to produce the body weights of animals restricted

on

> the LF diet throughout life. Life span, body weight, and leptin

levels

> were measured. RESULTS: Animals restricted throughout life lived the

> longest (p < 0.001). Life span was not different among animals that

> had been obese and then lost weight and animals that had been

nonobese

> throughout life (p = 0.18). Animals that were obese and lost weight

> lived substantially longer than animals that remained obese

throughout

> life (p = 0.002). Diet composition had no effect on life span (p =

> 0.52). DISCUSSION: Weight loss after the onset of obesity during

> adulthood leads to a substantial increase in longevity in rats.

>

> PMID: 15897478