Re: The case against Calorie Restriction?

[Guest guest]

Hi Rizwan:

I do not have time to address this fully right now. Will do later if

no one else does first.

But a couple of points. First, no one knows whether CR increases

lifespan in humans, INCLUDING THE AUTHOR OF THAT PIECE AND INCLUDING

US!

Second, there are quite a number of totally irrational statements in

that article that make no sense. So if I were you I wouldn't pay any

attention to it. But if a serious scientific study were to provide

decent evidence one way or the other I would certainly pay attention

to it.

More on this another time perhaps. Have a good weekend.

Rodney.

-- In , " rizwankherati " <helper11@e...>

wrote:

> Hi,

>

> Has anybody read the points made against the antiaging affects of

CR in

> humans found here:

>

> http://www.geocities.com/longevityrpt/lr65.htm#Caloric%

20Restriction%

> 20Does%20not%20Slow%20Ageing%20in%20Humans

>

>

> I will appreciate your comments.

>

> Thanks

>

> Rizwan

[Guest guest]

Rather limited scope of argument, given that CR has resulted in life

extension in almost every species in which it has been tested. Test in

primates are in progress, as are our own personal experiments.

On 6/17/05, rizwankherati <helper11@...> wrote:

> Hi,

>

> Has anybody read the points made against the antiaging affects of CR in

> humans found here:

>

> http://www.geocities.com/longevityrpt/lr65.htm#Caloric%20Restriction%

> 20Does%20not%20Slow%20Ageing%20in%20Humans

>

>

> I will appreciate your comments.

>

> Thanks

>

> Rizwan

>

>

>

>

>

>

>

>

>

[Guest guest]

Hi Rizwan:

Here is my response. Best to show the full article with my responses

inserted into the text. My comments are in XXXXX my stuff between

the Xs, format XXXX. His article is after > characters:

>Caloric Restriction Does not Slow Ageing in Humans

>by Skrecky <oberon@...>

XXXXX A nice categorical title, don't you think, for an article on a

topic where all the experts agree there is considerable uncertainty?

XXXXX

>There has been some speculation that caloric restriction might be

>able to retard the rate of aging, and extend maximum human life span

>beyond 120 years of age. (For example see the book The 120 Year Diet

>by Roy Walford)

>Recent evidence indicates that the anti-aging effect of caloric

>restriction, which has been documented in rodents, is not operative

>in humans. A low body-mass index does have a positive association

>with reduced mortality rates in humans.

>However recent research indicates that this is due to a negative

>association between BMI and physical fitness. After physical fitness

>is accounted for, there exists no further effect of BMI on

>mortality. See the following table from (International Journal of

>Obesity 19 Suppl: S41-S44 1995.

>All Cause Death Rates

> BMI Fitness

> Low Moderate High

> <27 52.1 28.6 20.0

> 27-30 49.1 29.8 19.7

> >30 62.1 18.0 (moderate & high together)

XXXXX First, to take this study seriously we are supposed to believe

that THE OBESEST PEOPLE ARE THE HEALTHIEST, since this shows that

their death rate is the lowest of all categories shown. I do not

have access to that study right now. But I believe I read it some

time ago. Not much information is provided that would enable us to

quickly find it. No authors' names. No PMID number. (Perhaps that

is because they do not want us to read it?) BUT, IIRC (please

correct me if I am mistaken) the principal author works for an

organization the vast majority of whose business revenues are derived

from selling books, courses, equipment and advice promoting aerobic

EXERCISE and the author's BMI is well above 30. (Jeff may be able to

confirm/refute this for us). XXXXX

XXXXX Second, note his BMI categories are: below 27; 27 - 30; and

above 30. Isn't this a bit weird? Most people use more rational

ranges like, perhaps, less than 20; 20 - 25; 25 - 30; 30 - 35 and

above 35, say. From spending all my working life studying numerical

analyses, whenever someone does something like use odd ranges from

which to draw their conclusions, red lights start flashing. There

almost always is a reason. That reason often is that if they had

used the same ranges everyone else uses, the point they are

determined to make is disproven. Not joking. You see this all the

time. Possibly that may be a factor in this case. XXXXX

XXXXX Third, there are plenty of studies which, to the contrary,

show that lifespan is shorter at higher BMIs. One recently published

found BMIs between 20 and 22 to have lowest mortality. It was posted

here at the time. Another study done in the Netherlands which I

posted here about a year ago showed that for BMIs between 25 and 35

lifespan was shortened by almost exactly one year for each one unit

rise in BMI. Unfortunately they did not have a big enough sample of

people with a BMI around 20 to draw any conclusions about those with

very low BMIs. XXXXX

XXXXX So you have to wonder why the author of this piece, Skrecky,

omitted to note that there were other studies that conflicted with

the one study he had decided to write about, and ignore the others.

There are only two reasons to ignore contrary evidence, and that is

either because you have an agenda, which is NOT to make a fair

assessment of the evidence; or simply that the author of the piece is

just ignorant of the other studies - hardly a recommendation to take

his views seriously either. XXXXX

XXXXX Fourth, as is true of all these types of studies, many people

who are thin, are thin because they are sick and about to die.

Others are thin because they have intestinal absorption problems

which may result is nutrient deficiencies which will negatively

affect their health long term. [Audrey Hepburn, according to her

obituary, was thin because she nearly starved to death as a child in

WWII Holland. She never recovered from that and could not put on

weight no matter how hard she tried.] If these people are not very

carefully excluded from the data from such studies then it will tell

you little about the mortality rates or lifespans of thoroughly

healthy people who have to exert pronounced efforts to keep their

weights in line, and satisfy the RDAs, but succeed. Did this study

take these precautions? I dunno. But if I had to bet on it I would

bet they didn't. XXXXX

XXXXX Fifth, studies in centenarians (New England Centenarian Study,

posted here by me, within the past year) show that there are

absolutely no common denominators among them regarding exercise.

Their exercise data are all over the map. Some exercised

extensively, some moderately, some modestly, some not at all. Of the

types of exercise taken by those who did exercise, that similarly was

all over the map. Did Skrecky mention this? Of course not. Why

not? Draw your own conclusions. But clearly the centenarian study

data are totally contrary to the thrust of his article and the study

he presented as 'evidence'. XXXXX

XXXXX Sixth, this study is now ten years old, it appears - a dog's

age in nutrition science. And what have the more recent studies been

showing? That monkeys on CR are showing exactly the same highly

beneficial changes in their important biomarkers that the mice

showed. Ahem. So we are supposed to believe, now, that CR benefits

every species up to and including moneys, but humans are the only

species that does not benefit? That doesn't seem highly likely. But

I suppose it is also possible that the sun is not gonna rise over the

Sahara tomorrow. XXXXX

>While the above data indicate that the body mass index itself is not

>a primary driving factor for mortality in humans, the case it makes

>against caloric restriction exerting an anti-aging effect is not air-

>tight. What is needed is a false prediction from a postulated anti-

>aging effect of caloric restriction that could then be used in turn

>to falsify that hypothesis. I believe there exists one such

>prediction.

>Lower BMI is associated with reduced mortality in young and middle-

>aged humans. If caloric restriction retards the rate of aging and

>extends maximum life span in humans one must expect that a lower BMI

>would be significantly associated with reduced mortality in aged

>humans. If such an significant association is not found then caloric

>intake is not operative in modifying the rate of aging in humans and

>life spans beyond 120 will not be possible by reducing caloric

>intake.

>In humans over 84 years of age BMI has not been found to exert any

>significant effect on mortality. (New England Journal of Medicine

>338: 1-7 1998 & Arch Intern Med 157: 2249-2258 1997) Therefore since

>no association has been found between BMI and mortality in aged

>humans, then caloric restriction is not operative in modifying the

>rate of aging in humans.

XXXXX Same applies as above. Were the people who had low BMIs

because they were unhealthy excluded from the study? Some times an

effort is made to exclude them by ignoring those who are overtly ill,

and/or who die in the short term after the study starts. But this

does nothing to weed out others, like those with intestinal

absorption problems (eat like a horse and never put on weight) who

likely have had lifelong deficiences of some key nutrients, no matter

what they ate. XXXXX

>The fact that caloric restriction dramatically extends life span in

>mice, but not apparently in humans requires some explanation. Here

>is one. In mice caloric restriction is associated with torpor, which

>can act to reduce tumor growth. In C57BL/6J mice blocking torpor, by

>increasing housing temperature to 30 C reduced the increase in

>average life span associated with caloric restriction from 47% to

>just 4%. Since humans neither experience torpor, nor suffer from

>cancer to the degree that mice do the effect of caloric restriction

>in mice can not be generalized to include humans. For example in

>human centenarians only 4% die from cancer. By comparison

>cardiovascular disease accounts for 63% of deaths in those aged 95

>and over. (Epidemiology 8: 501-504 1997) Thus it is cardiovascular

>disease and not cancer that is the major longevity limiting factor

>in humans. It is possible that potassium intake may be a major

>dietary modulator of human longevity. A high potassium intake has

>been found to reduce stroke associated mortality to zero. (New

>England Journal of Medicine 316: 235-240 1987)

XXXXX My dictionary defines torpor as " extreme sluggishness " . So

which mice is he talking about? Many of us have seen Dr. Walford's

mice, on a PBS 'Scientific American Frontiers' program. It was the

ad lib mice that were in such a state of torpor that they hardly

moved when the got older. But the mice of the same age, that had

been on CR, were running around like crazy. Sorry, Skrecky, I think

you have your facts in reverse on this one. XXXXX

XXXXX So, he is now saying that cancer doesn't matter? LOL. Well

to most of us cancer matters a lot. And CR in the mice delayed the

onset of cancer by the human equivalent of 25 years. So much so,

that the incidence of cancer in the mice, between the human-

equivalent ages of 70 and 100 was reduced by by 75%!!! I will be

happy to take that 75% reduction, even if Skrecky doesn't think it

much matters. He appears to be grasping for straws on this point.

XXXXX

XXXXX And he says, correctly for once, that heart disease is the

most important factor for humans. But again that does not support

HIS side of the argument, it supports ours. Is he ignorant of it?

Or is he intentionally failing to disclose it? (again,

sigh) ......... the results of Luigi Fontana's WUSTL study? It

showed, as we presumably all know here, that humans on CR have what

can only be described as mind-blowingly good CVD risk profiles. Like

an AVERAGE BP of 100/60. Like AVERAGE insulin and hsCRP reduced by

about 80%!!! Eighty percent! With very low LDL and triglycerides

and extraordinarily high (good) HDL. Really, if Skrecky is unaware

of the WUSTL study then he truly is extraordinarily ignorant about

the subject matter he has chosen to write about. Or is he

intentionally failing to disclose it? Either way it indicates to me

that you wouldn't want to take his word for anything. XXXXX

XXXXX Now this is not to say that all the hoped for benefits of CR

are proven in humans. We know pretty much for certain that CR goes a

long way to rectangularizing the curve - in other words to allow many

more people to live out a full healthy normal life and not die early

from the unnecessary diseases commonly associated with aging. The

place where there is still room for doubt is whether, and if so to

what extent, CR extends MAXIMAL LIFESPAN in humans. No one knows

yet. We can not know until there is convincing evidence one way or

the other, and these studies will take a very long time. But really

that is a detail. As said, CRON extends maximal lifespan

is every species for which we have the data, so it seems highly

likely it will do so also in humans. But even if it doesn't, I want

to avoid the diseases typically associated with aging - cancer and

heart disease (which the evidence strongly suggests CRON will do) -

to live long enough to be able to catch the next health wave (major

health technical advance) whatever that turns out to be. XXXXX

XXXXX Corrections to any of the above will be much appreciated.

Even from Mr. Skrecky! Thanks. XXXXX

Rodney.

> Hi,

>

> Has anybody read the points made against the antiaging affects of

CR in

> humans found here:

>

> http://www.geocities.com/longevityrpt/lr65.htm#Caloric%

20Restriction%

> 20Does%20not%20Slow%20Ageing%20in%20Humans

>

>

> I will appreciate your comments.

>

> Thanks

>

> Rizwan

[Guest guest]

Rodney -

Why hasn't anyone pointed out that all of his references are

to " Caloric restriction " yet he leaves out " With optimal nutrition " ?

His points are completely devoid of any controls for nutrition

levels.

Case closed in my book.

Nick

--- In , " Rodney " <perspect1111@y...>

wrote:

> Hi Rizwan:

>

> Here is my response. Best to show the full article with my

responses

[Guest guest]

Hi Nick:

Good point. Thank you!

Rodney.

> > Hi Rizwan:

> >

> > Here is my response. Best to show the full article with my

> responses