3 replies to this topic

[Brett Black]

In this special issue of the journal Biogerontology(Volume 7, Number 3 / June 2006), twelve international experts who have worked in the field of dietary restriction(DR) answer the question "Do you think that DR can increase longevity in all species, particularly in human beings?" Roughly half take the positive position, whilst the other half take the negative position:

http://www.springerl.../1389-5729/7/3/

[niner]

Thanks for posting that. I was surprised to find that those in the negative position actually had some decent arguments. From the primate experiments that are ongoing, and from human biomarkers, I was under the impression that at the very least, an increase in healthspan was quite likely. I have never understood the widespread obsession with Max LS, as opposed to Average LS. By definition, your odds of reaching Max LS are 1/7,000,000,000 and getting worse, since it's a moving target. On the other hand, your odds of reaching Average LS are quite good. For virtually everyone, an increase in the average is a win, while an increase in Max with no change in average is a win for almost no one. Interventions that increase average LS without increasing max are derided by many as "merely curve squaring". Today, if you purport to be an immortalist, curve squaring is a tremendous win, since that makes it more likely that you will be around long enough to benefit from the eventual interventions that will extend maximum LS.

[scottknl]

For me the key piece of evidence is the Okinawins. They do live longer than people with richer diets. So just from that we know that CR works to some degree. If you factor in some kind of improvement from optimizing the diet thru use of diet tracking software and further restricting calories to say 20 - 30% (compared to ad-lib for the same person), I think it's likely to add a little bit more to the end result.

I have to say that it's unlikely we will really know the results in any definitive way since more robust methods of life extension based on stem cell technologies are likely to be available before a statistically significant number of CR practitioners die. Many CRONIES are around 50 - 60 years old now and it's likely that they will still be around 40 years from now at 90 - 100 years old which would be normal life span for a person taking really good care with their diets and health. 40 years is an eternity at the current pace of medical research.

[Mike C]

many years ago i made a similiar argument on the CR society list. Namely that woman -especially Japanese woman eat a CR diet relative to their western coun terparts-about 20% less and significantly they do this little experiment from day one-their whole lives. Thus relative to westerners japanese woman represent a form of CR-and body size is probably irrelevant. The CR people shot it down-just trampled all over it-see archives-well I never thought their arguments were satisfactory so it is especially interesting to me to see this idea is out there and being considered by scientists that put doubt on the CR hypothesis in humans based on the relative CR status of japanese woman who we would expect to be living 20% longer than those westerners who they are compared to but who do not even come close to that kind of extenesion of life.

Mike C.