• Log in with Facebook Log in with Twitter Log In with Google      Sign In    
  • Create Account
  LongeCity
              Advocacy & Research for Unlimited Lifespans

Photo
- - - - -

Has calorie restriction been debunked as a method to extend human life?

diet

  • Please log in to reply
5 replies to this topic

#1 Kimer Med

  • Guest
  • 254 posts
  • 60
  • Location:New Zealand
  • NO

Posted 22 January 2019 - 11:20 PM


There was a study in 2012 showing that calorie restriction was not effective in rhesus monkeys as a method of extending lifespan, suggesting that it's also unlikely to work in humans:

 

https://www.nature.c...ong-run-1.11297

 

The information in that article about the way the previous studies in primates were run is pretty shocking (high sucrose diets, etc), further strengthening the argument against it working in humans, IMO.

 

Why is calorie restriction still being preached? Have there been any good counterarguments to this research? 

 

I'm not talking about periodic / intermittent fasting -- which, as I understand it -- is focused more around health and healthspan than maximum lifespan.

 


  • unsure x 1

#2 xEva

  • Guest
  • 1,594 posts
  • 24
  • Location:USA
  • NO

Posted 23 January 2019 - 03:35 PM

If you're talking about CR in its 'sustained' form, as a constant restriction with a more or less flat graph of daily calorie intake, then, at least on this forum, it does not appear as popular as it was ~10 year ago.  Or maybe I'm wrong? We should have a poll on this.

 

 


  • Good Point x 1

#3 Saintor

  • Guest
  • 39 posts
  • 24

Posted 10 February 2019 - 12:01 PM

I don't think that it has been 'debunked'.

 

For one negative, there are way many more positives.

 

From the same publisher 2014

https://www.nature.c...cles/ncomms4557

 

Results in thesus monkeys

 

ncomms4557-f1.jpg

 

 


Edited by Saintor, 10 February 2019 - 12:03 PM.

  • unsure x 1
  • Agree x 1

#4 Matt

  • Guest
  • 2,862 posts
  • 149
  • Location:United Kingdom
  • NO

Posted 16 February 2019 - 07:22 PM

No, it hasn't been debunked in humans. There were many inconsistencies in the rhesus monkey studies with how the monkeys responded to CR. Humans on CR appear to respond much more favorably than rhesus monkeys and in a way that is more similar to how rodents respond. I updated an article which discusses some of this, you can read it here. I'd also recommend reading this article published in nature.

 

There was also a more recent study that showed Lemur monkeys responded to CR well with a 50% increase in median lifespan (9.6 years vs 6.4 years). If they factored out accidents in the group, 60% of the CR monkeys were alive at 13 years old, which is longer than their previously recorded lifespan of 12 years.

 

I think a lot of people now just dismiss CR as a way to extend lifespan in humans, and I know a few people who quit the diet after the rhesus monkey study came out. But I'll continue to stay on CR as long as there isn't any other proven way to extend lifespan that is robust as CR. And from testing and personal experience, I've had a lot of benefits from the diet anyway.

 

Maybe it's possible that some people just don't do well on the diet and it might be bad for them, as some research papers suggest when they compared lifespan results for different strains of mice on CR. Although, a subsequent article found that CR worked in strains of mice which were able to hold onto fat better and not have a big decrease in core body temperature

 

 

Liao CY, Rikke BA, Johnson TE, Gelfond JA, Diaz V, Nelson JF.
Fat maintenance is a predictor of the murine lifespan response to dietary restriction.
Aging Cell. 2011;10:629–639


  • like x 3
  • Agree x 1

#5 Mind

  • Life Member, Director, Moderator, Treasurer
  • 18,997 posts
  • 2,000
  • Location:Wausau, WI

Posted 17 February 2019 - 11:30 AM

I don't think it has been debunked. Most people who are able to maintain CR for long periods of time (years or decades), seem to be mostly very healthy and have better aging biomarkers. Reason has speculated that you could gain a few years of life through CR but the gains will probably not be as dramatic as those seen in short-lived mammals or simpler life forms. The key point is that CR does not "rejuvenate" it only slows down the aging process.


  • Good Point x 1

#6 xEva

  • Guest
  • 1,594 posts
  • 24
  • Location:USA
  • NO

Posted 17 February 2019 - 08:48 PM

I don't think it has been debunked. Most people who are able to maintain CR for long periods of time (years or decades), seem to be mostly very healthy and have better aging biomarkers. Reason has speculated that you could gain a few years of life through CR but the gains will probably not be as dramatic as those seen in short-lived mammals or simpler life forms. The key point is that CR does not "rejuvenate" it only slows down the aging process.

 

It's true that CR does not rejuvenate, but long-term fasting does (during the refeeding stage, which is absent in the sustained CR). The rejuvenating effect is startling and lasting for people under 55 but less so for older folks and is transient in those over 60+.

 

My impression is that popularity if the original form of CR has been supplanted by various forms of fasting, from time restricted feeding  to intermittent fasting. I think all  these forms lead to a diminished total calorie intake, if counted, say, monthly, or, in case of long-term fasting, for a whole year. I also think this is more natural, in the sense that, in nature, times of plenty and scarcity intersperse and are reflected in the feeding patterns.

 

Also, it was extensively discussed years ago, in several threads, that CR'd mice, due to their super-fast metabolism, end up fasting; i.e. they finish their portion in a couple of hours, and end up fasting proper-- including going into ketosis! -- until their next meal. This was definitely true when they were fed once a day, and I think it was also true, to an extent, when they were fed twice a day. This meant that they had a refeeding stage. It's too bad that the differences in metabolic rate are seldom mentioned.

 

But hey, whatever works for you. I may be biased in this regard since my introduction to CR was through long-term fasting. Like many people who tried it both ways, I find it easier not to eat at all, for a stretch, than continuously struggle with hunger.


Edited by xEva, 17 February 2019 - 09:14 PM.

  • Agree x 2





Also tagged with one or more of these keywords: diet

1 user(s) are reading this topic

0 members, 1 guests, 0 anonymous users