
Caloric restriction reduces age-related and all-cause mortality in rhesus monkeys - efficientarch
http://www.nature.com/ncomms/2014/140401/ncomms4557/full/ncomms4557.html
======
naterator
It should be noted that a parallel study[1] at the National Institute for
Aging (NIA) found that this was not the case. The authors of this study (UW)
claim (as far as I understand) that the NIA study was flawed because both
Control and Calorie Restricted (CR) monkeys were fed diets that were both
restrictive, and not sufficiently different. There also seem to be some debate
about the composition of the diets. The controls in the UW study were allowed
to eat as they pleased (i.e. become fatties if they wanted). They claim that
if both "modest" or "moderate" CR are equivalent, it would be a very important
conclusion. The practical consequence, if true, would be that we wouldn't have
to starve ourselves too much.

Mouse models had suggested years ago that calorie restriction could lead to
~%50 increase in lifetime. However, the problem with mouse studies is that
they are pretty different, and also the mice they use are really inbred and
perhaps non-ideal examples. The conclusion from the primate studies is really
stacking up to be a common sense "eat in moderation, healthy, and you'll live
at least a little longer, maybe a lot". Not really groundbreaking stuff, to be
honest. And still not conclusive when you consider the resources that went
into these studies. This also teaches us nothing about mechanisms, which would
be _really_ useful. Just my cursory assessment so far.

[1] [http://www.nytimes.com/2012/08/30/science/low-calorie-
diet-d...](http://www.nytimes.com/2012/08/30/science/low-calorie-diet-doesnt-
prolong-life-study-of-monkeys-finds.html)

~~~
exratione
The publicity materials for this recent set of results do a good job of
explaining why the researchers think that the NIA study is flawed. In essence
the NIA control monkeys are probably on CR.

[http://www.newswise.com/articles/monkey-caloric-
restriction-...](http://www.newswise.com/articles/monkey-caloric-restriction-
study-shows-big-benefit-contradicts-earlier-study)

“In Wisconsin, we started with adults. We knew how much food they wanted to
eat, and we based our experimental diet on a 30 percent reduction in calories
from that point.” In contrast, the NIA monkeys were fed according to a
standardized food intake chart designed by the National Academy of Science.

Through their own experience in monkey research, and by reference to an online
database recording the weight of thousands of research monkeys, the Wisconsin
researchers concluded that the NIA controls were actually on caloric
restriction as well, says Colman. “At all the time points that have been
published by NIA, their control monkeys weigh less than ours, and in most
cases, significantly so.”

Weindruch also points to some results from the NIA that seem to contradict the
“no significant result” analysis. Twenty monkeys entered the NIA study as
mature adults, 10 in the test group and 10 in the control group, and five of
these (four test monkeys and one control monkey) lived at least 40 years.
“Heretofore, there was never a monkey that we are aware of that was reported
to live beyond 40 years,” Weindruch says. “Hence, the conclusion that caloric
restriction is ineffective in their study does not make sense to me and my
colleagues.”

------
jasonkolb
Caloric restriction is absolutely fascinating in all forms. I think
intermittent fasting might be the best-known variant of this, but there are
others. All of them cause dramatic changes in the way bodies function, from
changing the hormones secreted to changing the form of fuel it uses to run
itself (e.g. ketones in low-carb diets instead of glucose).

Caloric restriction has a whole bunch of knock-on effects, any one of which
could have a huge impact on health and aging. For example, restricting
calories means that you're restricting protein. Most people think of protein
as a good thing, but that's what stimulates the hormone IGF-1 to be secreted,
which is necessary for growth of all kinds--muscle growth (which is why
bodybuilders eat as much protein as possible), but also including cancer.

I've seen research that suggests that cells don't go into "repair mode" in the
presence of IGF-1. This is just one example of a possible mechanism that
caloric restriction could have a hugely beneficial effect on aging and illness
in general.

I have a half-written blog post about this I should push out. I'd love to get
some more conversation going around this.

~~~
KVFinn
>For example, restricting calories means that you're restricting protein. Most
people think of protein as a good thing, but that's what stimulates the
hormone IGF-1 to be secreted, which is necessary for growth of all kinds--
muscle growth (which is why bodybuilders eat as much protein as possible), but
also including cancer.

While people on CR do seem to try and keep IGF-1 on the lower side, there's no
consensus on protein yet. Most seem to eat a normal proportion, (though still
less than average person since their overall intake it lower.).

I have seen some people doing CR specially avoid whey protein because it's
known to particularly raise IGF-1 (which is why on the other hand people
trying to maximize size of muscles like it)

~~~
X4
Ok, I think most of you who read PROTEIN, may misunderstand a bit here, I'll
add a bit of info to clarify the protein debate a bit.

There are almost indefinite combinations of proteins, many of which have
vastly different effects on the body and it's cells. To shed a bit of light on
proteins, you should know that most enzymes are proteins too
[http://en.wikipedia.org/wiki/Enzyme](http://en.wikipedia.org/wiki/Enzyme)

Some forms of 'proteins' may increase cancerous growth, other may inhibit it
and there are many of such activators/inhibitors, just so you know. Only take
a look at
[http://en.wikipedia.org/wiki/Myosin](http://en.wikipedia.org/wiki/Myosin)
which there are proteins ("enzymes"), which may inhibit it, leading to a
super-muscular body. It's a very small change, but the result is not what you
would expect from just a protein. The contrary is true too, it could have
damaging effect too. We are NOT talking about supplements here, but the form
of proteins that occur in Nature. They are by far not researched enough to
give any form of advice and there are still new breakthroughs, findings and
surprises made in the area.

Roughly saying that no calories means, more lifetime, is like saying that not
fueling a motor will increase it's lifetime.

Human Life is not about getting as old as possible anyway. My personal opinion
is that it's there to bring healthy and smart kids to the world, which help in
the betterment of the world with their creativity, skills, ideas, muscles,
efforts and visions. Simple as that.

------
gregwebs
This paper rehashes 2 studies. In the original Wisconsin one that showed a
great benefit to CR

    
    
        ... were fed a semi-purified, nutritionally fortified, low-fat diet containing 15% protein and 10% fat. 
    
    

The monkeys without CR ended up getting diabetes and they were giving them
insulin. This study made a big splash, but as others point out it probably
really only helps prove that eating less crap is good for you.

This paper appears to include some of the same authors of the Wisconsin study
and tries to explain why the NIH performed a study that did not replicate
their results. This paper claims that the control group in the NIH study
actually underwent CR by comparing them to a database of captive primates. If
that is true, then the title still seems strange, because it doesn't mean the
NIH study provides meaningful supporting evidence, it means it was an invalid
test of the CR hypothesis and instead it provides some extremely weak
supporting evidence of the CR hypothesis.

As a side note, there is evidence that the CR benefit is from protein
restriction and possibly just avoiding protein imbalances.
[https://chriskresser.com/do-high-protein-diets-cause-
kidney-...](https://chriskresser.com/do-high-protein-diets-cause-kidney-
disease-and-cancer) (scroll to Is protein to blame—or is methionine?)

------
tokenadult
What's interesting about human all-cause mortality trends is that human beings
in the developed countries have been gaining three months of lifespan for
every year that they live (sometimes described as "six hours each day").[1]
Girls born since 2000 in the developed world are more likely than not to reach
the age of 100, with boys likely to enjoy lifespans almost as long. The
article "The Biodemography of Human Ageing" by James Vaupel,[2] originally
published in the journal Nature in 2010, is a good current reference on the
subject. Vaupel is one of the leading scholars on the demography of aging and
how to adjust for time trends in life expectancy. A lot incremental
improvements in both public health and in medical practice, as well as much
better nutrition than in the old days, are steadily increasing life
expectancy.[3] This is happening for people of all ages; life expectancy at
age 40, at age 60, and at even higher ages is still rising, and all-cause
mortality and morbidity declining, throughout the developed countries of the
world.[4]

So the monkey research needs to be meshed in with human research that shows
that mildly "overweight" (if fit) human beings have better mortality outcomes
than human beings of normal weight[5] to tease out what the causation is for
health outcomes of different patterns of nutrition. The example of
Rimonabant[6] shows that sometimes an animal model doesn't adequately predict
treatment effects in human subjects.

[1]
[http://www.prb.org/Journalists/Webcasts/2010/humanlongevity....](http://www.prb.org/Journalists/Webcasts/2010/humanlongevity.aspx)

[2] [http://www.demographic-
challenge.com/files/downloads/2eb51e2...](http://www.demographic-
challenge.com/files/downloads/2eb51e2860ef54d218ce5ce19abe6a59/dc_biodemography_of_human_ageing_nature_2010_vaupel.pdf)

[3]
[http://www.slate.com/articles/health_and_science/science_of_...](http://www.slate.com/articles/health_and_science/science_of_longevity/2013/09/life_expectancy_history_public_health_and_medical_advances_that_lead_to.html)

[4]
[http://www.nature.com/scientificamerican/journal/v307/n3/box...](http://www.nature.com/scientificamerican/journal/v307/n3/box/scientificamerican0912-54_BX1.html)

[5]
[http://www.ncbi.nlm.nih.gov/pubmed/23280227](http://www.ncbi.nlm.nih.gov/pubmed/23280227)

[6]
[http://www.ncbi.nlm.nih.gov/pubmed/19578688](http://www.ncbi.nlm.nih.gov/pubmed/19578688)

~~~
jessriedel
> Girls born since 2000 in the developed world are more likely than not to
> reach the age of 100, with boys likely to enjoy lifespans almost as long.
> The article "The Biodemography of Human Ageing" by James Vaupel,[2]
> originally published in the journal Nature in 2010, is a good current
> reference on the subject.

You or someone else presented this highly speculative claim as fact a long
time ago on HN. I've tried to find the comment link, but I can't.

In any case, the support for this supposed fact is very dubious. You link to
one article by Vaupel in Nature who, in making this claim, cites _only_ this
paper

[http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2810516/](http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2810516/)

by Christensen et al. The paper says, in the abstract,

> If the pace of increase in life expectancy in developed countries over the
> past two centuries continues through the 21st century, most babies born
> since 2000 in France, Germany, Italy, the UK, the USA, Canada, Japan, and
> other countries with long life expectancies will celebrate their 100th
> birthdays.

Very few medical researchers are likely to find that "if" statement at all
plausible, so this claim about most newborn girls living to 100 is bogus. If
you have a better source for this claim, please present it. Otherwise, stop
posting it.

~~~
tokenadult
(Thank you for your concern.) How would one prove this claim wrong? There is
signal in current mortality and morbidity statistics about how long the
individuals now alive will last before they die off. Is anyone interpreting
this signal from official medical reports any differently from Vaupel and
Christensen? Both Vaupel and Christensen are very well respected demographers
(as Vaupel's publication in _Nature_ should adequately suggest to readers
familiar with the scientific literature). Paul Graham has a great essay online
titled "How to Disagree"[1] and I invite you to apply those steps in any
thread on Hacker News where you see a factual claim with which you disagree
(as I think I have seen you do in countless thoughtful earlier comments that
have been posted here from your keyboard).

 _If you have a better source for this claim, please present it. Otherwise,
stop posting it._

What you seem to be objecting to here is not the factual statement (you have
not suggested any reason to doubt the factual statement, and haven't cited
anyone who works in demography) but rather the strikingly concrete way in
which the statement was made. But that manner of making the statement was
chosen by Vaupel (in agreement with Christensen, whose works on the topic I
have also read) and I'm just passing on the ideas of recognized experts whose
published papers on the topic look plausible to me and look especially
plausible to demography researchers on human aging I know locally. I learned
about the papers of these two authors from local researchers who sometimes
collaborate with Vaupel and Christensen (especially Christensen).

It shouldn't be objectionable here on Hacker News to pass on user-readable
citations to published scientific literature that looks plausible to other
scientists with a basis of knowledge in the subject. You are asking me to
change my overt behavior as one Hacker News participant among thousands. Where
in the Hacker News guidelines[2] do you find a problem with behavior like mine
here? Hacker News seems very tolerant of predictions of the future, and indeed
some of the favorite topics here revolve around predictions of the future.

[1] [http://paulgraham.com/disagree.html](http://paulgraham.com/disagree.html)

[2]
[http://ycombinator.com/newsguidelines.html](http://ycombinator.com/newsguidelines.html)

~~~
jessriedel
All fields are populated with multiple experts. The opinion of those experts
on some issues will be broadly in agreement, and on other issues they will
have a wide range.

Finding one expert who presents the _conditional claim_ of another expert as
_unconditional_ , and (you) then asserting this claim as accepted fact is
highly misleading. This is especially true when that unconditional claim is
almost certain to be disputed by the majority of experts. Giving your
citations reduces the friction necessary for people to identify how you are
being misleading, but it's not a blanket pass to mislead.

Furthermore, it won't always be the case that there will be a nerd like me
willing to dive into your citations to show why they don't support your claim.
In this case, the veneer of authority that comes with listing many citations
can easily overwhelm the benefit they provide, leading to more misinformation
than if your speculative claim had been uncited and therefore ignored.

> How would one prove this claim wrong?

You would ask a few of experts if they think it's plausible that life
expediencies would follow the same trajectory in developed countries this
century as they have the past century. I conjecture that almost all those
experts would reply "no", probabaly citing (1) the fact that the mortality
rates at elderly ages has leveled off for many decades in developing countries
and (2) that almost all the increases in life expectancy comes from reducing
infant mortality and the spread of infectious diseases.

Indeed, the soft ceiling on human longevity has not budged much since Psalms
90:10 was written about 3 millennia ago:

> The days of our years are threescore years and ten; and if by reason of
> strength they be fourscore years, yet is their strength labour and sorrow;
> for it is soon cut off, and we fly away.

~~~
tokenadult
_I conjecture that almost all those experts would reply "no"_

Have you asked even one? Have you asked any experts at all? This is what is so
puzzling to me about this line of questioning--is the question actually
prompted by acquaintance with the subject, or is it of a piece with doubting
any other scientific claim? What if the projection is correct, even though you
have trouble believing it? I have very little trouble believing the
projection, having a mother born in the 1930s who has passed her eighty-first
birthday, and having an aunt (her older sister) born in the 1920s who has
passed her ninety-fourth birthday. Plenty of people from much earlier birth
cohorts are already living into extended old age, so what is so daring about a
prediction that anyone who meets established long-term patterns of life
expectancy will live into an era with more progress in disease prevention and
treatment?

(In short, why have you cited no evidence whatever on this point?)

 _(1) the fact that the mortality rates at elderly ages has leveled off for
many decades in developing countries and (2) that almost all the increases in
life expectancy comes from reducing infant mortality and the spread of
infectious diseases._

That dual statement suggests you have not looked carefully at the link in my
original footnote 4

[http://www.nature.com/scientificamerican/journal/v307/n3/box...](http://www.nature.com/scientificamerican/journal/v307/n3/box/scientificamerican0912-54_BX1.html)

( _Nature 's_ repost of a chart originally available at the _Scientific
American_ website, but a dead link there now), in which it is shown that life
expectancy has been increasing steadily at ALL ages, including old ages. You
really need to read up more on this, or it's hard for anyone to discuss these
issues with you here. You are very careful to speak factually on other issues
here on Hacker News, so this is taking me a bit by surprise. Do you know of
any experts in this domain at all? Whose writings do you recommend?

------
mrfusion
People are mentioning caloric restriction not being worth it for humans
because of quality of life vs length of life.

However one thought that I find interesting, is that for our generation,
living just two or three extra years could potentially make a huge difference.

If you subscribe to the idea of a coming technological singularity, or even to
the idea that we're a few decades away from SENS escape velocity, you'd hate
to miss it by just a couple of years.

~~~
anigbrowl
Might be. I think the quality of life issues are overstated, but I'm an
ectomorph so I can change my food intake on a whim. Being hungry isn't a
distraction to me unless I'm very busy physically.

~~~
dfc

      > I'm an ectomorph
    

As in ecto|meso|endo-morph? I thought that the scientific community put that
idea in the trashcan.

~~~
anigbrowl
I'm just using it to tell you what I look like.

------
ca98am79
I thought about doing CR for a while - I read the "120 Year Diet," and was
considering giving it a try. Then I met up with a couple who was into hardcore
CR. I had dinner with them. Two things made me decide not to do it:

1) they seemed frail and weak - the man seemed to have a constant runny nose.
I felt that if he fell down he would break his hip. The risk of injury and
death from physical weakness seemed like it would counter any benefits from CR
for lifespan.

2) They put so much effort into measuring every ingredient, and running
computer programs with recipes to get the optimal nutrients with as little
calories as possible. It seemed to take so much time in preparation, and you
could mostly only eat at home.

~~~
Quaro
>Then I met up with a couple who was into hardcore CR.

You probably met someone on the extreme hardcore edge of it. Certainly it's a
spectrum and counting calories and nutrients with computer programs is
extremely normal today -- there are about a million programs that do it on
your phone for you including taking photos of bar codes, etc.

------
Beliavsky
I prefer this conclusion: "Study Suggests Lower Mortality Risk for People
Deemed to Be Overweight" [http://www.nytimes.com/2013/01/02/health/study-
suggests-lowe...](http://www.nytimes.com/2013/01/02/health/study-suggests-
lower-death-risk-for-the-overweight.html) .

------
dfc
According to the Nature Comms Open Access guidelines somebody paid $4,800 for
this article to be published under a BY-NC-SA license. In general who ends up
paying, the authors or the authors' respective institutions?

Open Access fees:[^1]

    
    
      (CC BY)    (CC BY-NC-SA)   Region
      -------------------------------------------------
      $5,200     $4,800          (The Americas)
      €3,700     €3,425          (Europe)
      ¥661,500   ¥612,150        (Japan)
      RMB33,100  RMB30,600       (China)
      £3,150     £2,915          (UK and Rest of World)
    

[^1]:
[http://www.nature.com/ncomms/open_access/index.html](http://www.nature.com/ncomms/open_access/index.html)

~~~
lsh
Typically the institutions, although I can't say specifically who paid in this
instance.

This is an interesting point and I'll raise it at work: should the sponsor of
an article be formally noted, along with the particulars of it's peer review,
license, etc?

Also, a shameless plug:
[http://www.ubiquitypress.com/publish](http://www.ubiquitypress.com/publish)
because OA isn't an expensive proposition, it just depends how it is handled
and by whom.

------
Harj
There is lots of interesting research on the links between caloric restriction
and the ageing process. It's the impact on the insulin and insulin like growth
factor (IGF-1) pathways that seems to be important:

[http://www.sciencedirect.com/science/article/pii/S0092867412...](http://www.sciencedirect.com/science/article/pii/S0092867412000049)

[http://kenyonlab.ucsf.edu/Kenyon_2010_Nature_rev.pdf](http://kenyonlab.ucsf.edu/Kenyon_2010_Nature_rev.pdf)

------
didgeoridoo
So if you don't eat much you may live longer.

It will certainly FEEL longer.

~~~
dexen
While stated as sarcasm, this is a very reasonable concern.

Suppose we can extend human life with Calore Restriction, but at the cost of
having to slow person's activity to the point that the overall amout of
actions (work, leisure etc.) remains the same as during shorter, more intense
life.

Would that still be worth it? What would a person gain through longer lifespan
if she was limited to roughly the same amout of activity anyway? Wouldn't
competing people gain advantage simply by being able to take advantage of
opportunities quicker?

~~~
crusso
Why speculate when we already have some data on activity levels under CR?

[http://en.wikipedia.org/wiki/Calorie_restriction#Activity_le...](http://en.wikipedia.org/wiki/Calorie_restriction#Activity_level)

~~~
KVFinn
Very interesting!

>Laboratory rodents placed on a CR diet tend to exhibit increased activity
levels (particularly when provided with exercise equipment) at feeding time.
Monkeys undergoing CR also appear more restless immediately before and after
meals.[62] Despite this brief daily period of increased activity overall
activity is no higher in CR than AL animals in youth after an initial period
of adaptation to the diet.[63] On the other hand, CR has been found to retard
the decline in activity that occurs during normal aging: in one study, animals
on a conventional diet "showed little activity" by early middle age, while
those on CR "were observed to run around the cage and climb onto and hang from
the wire cage tops throughout their life spans. In fact, the longest surviving
[CR] mouse was observed hanging from the top of his cage only 3 days before he
became moribund."

------
netcan
Am I the only one who finds this caloric restriction stuff depressing? If
starving for 50 years will increase my life I don't even want to know about
it. Stupid science. Next they're going to tell us that a combination of
caloric restriction & celibacy will do even more.

~~~
crusso
Ageing has been such an insurmountable problem, any methods that indicate that
there are ways to somewhat control it are promising and can lead to other
discoveries.

Perhaps CR only invokes the release of hormones that have a protective effect
on cells. Replicate the hormone and perhaps actual caloric restriction may not
be necessary.

~~~
netcan
OK crusso. I like the way you think.

From now on you are now in charge of all budgets, articles, blogs, tweets and
laboratories relating to CR research. May I suggest that your first fiat be
that CR will henceforth only be referred to by acronym.

~~~
crusso
My initials are CR and all. Makes sense. ;)

------
salimmadjd
> _Received 12 October 2013 Accepted 05 March 2014 Published 01 April 2014_

Am I the only one who finds this crazy? It takes 6 months from submission date
till publication!

The peer review process should move faster and become modernized. I
undrestand, you want to be published on prestigious journals, but Nature and
others can modernize to publish more. You can argue, we lost 6 months or half
a year of progress because of the pace of antiquated publication process.

~~~
lutusp
The counterargument should be obvious -- peer reviewers are often unpaid
experts who review pending articles in whatever spare time they happen to
have, between delivering lectures, research, and applying for grants. To speed
up the process woulds be to increase its cost, possibly very much, or to
degrade the peer review process.

The defects of another alternative should also be obvious -- paid peer
reviewers. If this change took place, people would line up for positions they
aren't qualified for on the simple ground that they can get paid to appear to
be what they aren't. Also, for many cutting-edge fields, there simply aren't
more than a handful of qualified reviewers at any price.

------
fatjokes
A lot of people are jumping to extremes. I don't take this to mean I should
starve myself. Instead this does encourage me to stop eating until I'm full,
just until I'm no longer hungry.

~~~
netcan
Well CR doesn't really refer to moderation. It refers to restrictions to the
point that it is unpleasant to most people.

------
higherpurpose
In related news:

[http://www.sciencedaily.com/releases/2014/03/140331194030.ht...](http://www.sciencedaily.com/releases/2014/03/140331194030.htm)

------
cliveowen
If I'm reading this correctly it says that the findings apply to 1) short
lived species and 2) rhesus primates. It also says that the effects of CR may
or may not be preserved on humans.

So the only real finding here seems to be that we are now able to extend the
lifespan of some monkeys.

~~~
crusso
While I don't disagree factually with what you're saying, the way you're
saying it sounds like a slight misunderstanding of the results here.

CR has been shown to have effects on short-lived species because that's all
that's been testable so far. CR has actually been remarkably consistent in its
effects across many different species.

The rhesus monkey studies are the first ones to attempt to replicate the
longevity results found in the previous tests that were performed on short-
lived species. The NIA rhesus study results released a short while back seemed
to be the first failure of replicating CR longevity results. This seemed to be
a blow to the theory that CR would be efficacious with higher primates.

However, this study is saying that the first rhesus study was conducted
incorrectly and that the results were incorrectly interpreted. They're
basically saying that scientifically, CR is still batting a thousand.

------
neves
Isn't this an year old published research that was widely reported?

------
RighteousFervor
I think these scientists should starve themselves instead of animals. It's
called having skin in the game.

~~~
gwern
Some of them do.

------
a8da6b0c91d
The test is lab grade monkey chow vs. less lab grade monkey chow. I don't
think one can extrapolate that eating less calories on a very high quality and
low toxin source of calories is better.

Monkeys do best on perfectly ripe and fresh tropical fruits. Is that what they
were eating? I really doubt it.

~~~
knodi123
Toxin is a buzzword that I use to tell when someone is easily deceived by woo-
woo fake science.

The idea that anything processed in a factory is full of "toxins" and anything
from nature is "healthy" is an irritating and pervasive fallacy.

Were you referring to a _specific_ toxin that is in their foods, or were you
using it in the more vague and hand-wavy "woo woo homeopathic" sense?

~~~
robododo
"High quality" in close proximity to "calories" is another sign of woo.

------
plg
'cause who really likes _eating_, anyway. A no-brainer to just reduce food.
Yeah that'll work.

Lots of things might reduce mortality and prolong lifespan. It's quite another
thing to ask whether these things are viable options for modern human beings.

~~~
todd8
In the early 90's my girlfriend was into CR. She was also into supplements. No
one that I've ever known took so many vitamins, minerals, herbs, and
antioxidants. She ordered them in bulk in powdered form and made a mess in the
kitchen mixing them up every day. Of course, now there's evidence that heavy
doses of vitamins aren't beneficial and may actually be harmful.

As to the calorie reduction, she was quite successful in controlling her diet.
She ordered guar gum in 50 lb sacks (from Tic Gums), mixing it with water to
have something in her stomach when she was hungry. She seemed to settle into a
routine that I don't think I could have tolerated. She didn't ever look
anorexic, but had very very low body fat.

She was very afraid of getting old and this motivated her. I think that
without some sort of pharmaceutical breakthrough that controls hunger, the
rest of us will not find CR practical.

~~~
ciupicri
> Of course, now there's evidence that heavy doses of vitamins aren't
> beneficial and may actually be harmful.

Could you be more specific, please?

~~~
manilafolder
This is an interesting meta-analysis of some of the studies done on the
efficacy of vitamins:
[https://www.youtube.com/watch?v=2mDrAQi1SwU](https://www.youtube.com/watch?v=2mDrAQi1SwU)
(Presentation by Dr. Jeffrey Tice of the University of California).

He covers vitamins A, E, and C around 18 minutes into the presentation.

