Interesting twist in the latest CR study of monkeys. This is from the National Institute of Aging study:
http://online.wsj.co...4017185860.html
Posted 29 August 2012 - 06:37 PM
Posted 29 August 2012 - 07:08 PM
Posted 29 August 2012 - 07:25 PM
Posted 29 August 2012 - 07:32 PM
But even that study had a question mark hanging over it. Its authors had disregarded about half of the deaths among the monkeys they studied, saying they were not related to aging. If they had included all of the deaths, there was no extension of life span in the Wisconsin study, either.
Edited by Chupoman, 29 August 2012 - 07:36 PM.
Posted 29 August 2012 - 07:42 PM
Once again this reminds me of the perplexing population studies across several cultures on different continents showing slightly overweight people have a lower death rate on average. I speculated that it boils down to the human body having enough energy reserves to battle late-life diseases. A bit overweight people have energy stores to help recover. CRONies have none. This could be mitigated by aggressive supplementation and increased caloric intake by CRONies who happen to get infections or cancer late in life, but it might be difficult after a long time on CR. Just speculating.
Posted 29 August 2012 - 07:50 PM
heathier longer but not lived longer => What did they die of, compared to the non-CR monkeys? I am always suspicious of health results when it is not a double blind study (treatment and health measures possibly involuntarily biased, I guess I'll have to find the time to read in details).The monkeys in this study did stay healthier longer
Is low bone density and elevated risk of fracture recognised among CRONies?lower bone density. Late life bone fractures in humans are very challenging for longevity
Posted 29 August 2012 - 08:06 PM
Posted 29 August 2012 - 08:58 PM
Posted 29 August 2012 - 09:10 PM
There were several differences between the studies that some have pointed to as possible explanations.
The composition of the food given to the monkeys in the Wisconsin study was different from that in the aging institute’s study.
The University of Wisconsin’s control monkeys were allowed to eat as much as they wanted and were fatter than those in the aging institute’s study, which were fed in amounts that were considered enough to maintain a healthy weight but were not unlimited.
The animals in the Wisconsin study were from India. Those in the aging institute’s study were from India and China, and so were more genetically diverse.
In those same years, though, studies in mice began indicating there might not be a predictable response to a low-calorie diet. Mice that came from the wild, instead of being born and raised in the lab, did not live longer on low-calorie diets. And in 2009, a study of 41 inbred strains of laboratory mice found that about a third had no response to the diets. Of those that responded, more strains had shorter life spans than had longer ones when they were given less food.
The response to that study was “absolute disbelief,” Dr. Austad said. “Even though the authors are well-respected calorie restrictors, people said the result was not interesting, that there was something weird about the mice.”
Edited by viveutvivas, 29 August 2012 - 09:12 PM.
Posted 29 August 2012 - 09:32 PM
Once again this reminds me of the perplexing population studies across several cultures on different continents showing slightly overweight people have a lower death rate on average. I speculated that it boils down to the human body having enough energy reserves to battle late-life diseases. A bit overweight people have energy stores to help recover. CRONies have none. This could be mitigated by aggressive supplementation and increased caloric intake by CRONies who happen to get infections or cancer late in life, but it might be difficult after a long time on CR. Just speculating.
Posted 29 August 2012 - 10:34 PM
One reason for that difference could be that the WNPRC monkeys were fed an unhealthy diet, which made the calorie-restricted monkeys seem healthier by comparison simply because they ate less of it. The WNPRC monkeys’ diets contained 28.5% sucrose, compared with 3.9% sucrose at the NIA. Meanwhile, the NIA meals included fish oil and antioxidants, whereas the WNPRC meals did not. Rick Weindruch, a gerontologist at the WNPRC who led the study, admits: “Overall, our diet was probably not as healthy.”
“When we began these studies, the dogma was that a calorie is a calorie,” Ingram says. “I think it’s clear that the types of calories the monkeys ate made a profound difference.”
Edited by stephen_b, 29 August 2012 - 10:37 PM.
Posted 29 August 2012 - 11:36 PM
Posted 30 August 2012 - 12:15 AM
Posted 30 August 2012 - 12:15 AM
Posted 30 August 2012 - 12:54 AM
Cancer:
It was completely prevented in the young CR animals so far which is a good performance, but wow --- look at how the old CR group are dropping like flies between 25 and 30 years of age from cancers. Must be too much protein or IGF-1 in the CR diet for those oldsters. Or there's a radiation source around the animal quarters somewhere!!! I would have expected about 1/2 as many deaths from cancer for CR based on the other animal studies where around 66% of cancers were prevented.
Posted 30 August 2012 - 02:42 AM
Posted 30 August 2012 - 03:23 AM
Edited by Matt, 30 August 2012 - 03:27 AM.
Posted 30 August 2012 - 03:31 AM
http://arc.crsociety...ad.php?2,211800I just read the fulltext and here are my initial comments:
The conclusions being reported are in reference to the cohort that began CR at older ages. Older aged rats put on CR similarly do not live longer. The age-related survival curves for the monkeys that started CR either at young or adult ages are still all in the 60-80% range, which the authors acknowledge does not answer whether or not CR extends monkey lifespan when started early in life. However, there is no significant survival advantage for the CR group at the moment.
The monkeys are not an inbred strain: they are genetically heterogeneous. The authors acknowledge the recent results showing that certain strains of mice have shorter lifespans when put on CR.
Nothing that was immediately obvious to me (except possibly the above) suggests that the authors conclusions are questionable. The controls were not fully ad libitum - the design was more akin to Walford's studies in which the control group is slightly restricted and the CR group is fed 30% less than the control group. In terms of length of life comparison to the University of Wisconsin study:
"*In an estimate of NIA’s current data (as of 1 December 2011) to the published WNPRC data summarized as of 22 February 2008 and reported in ref. 5, NIA monkeys, both control and CR, may have a lifespan advantage comparable to the WNPRC CR monkeys*."
In other words, the authors report that the lifespans for their control and CR cohorts are comparable to the lifespan for the CR cohort from the Wisconsin primates. I have not personally verified this.
I'll leave you with the blurb given with regards to health parameters:
"*Although they eat less (Supplementary Table 2) and weigh less13, young-onset CR monkeys lack many of the expected CR benefits. Fasting serum glucose levels were not significantly lower in the CR monkeys compared to control (Fig. 2c), and only the CR males had somewhat lower triglycerides compared to respective controls (P = 0.051) (Fig. 2d). However, in a ligature-induced model of inflammation in the oral cavity1, we have shown an improved immune response in young-onset CR monkeys and beneficial effects in T cells isolated from adolescent-onset males2*.
*The incidence of cancer was markedly improved in young-onset CR monkeys (P = 0.028 compared to controls); in fact, neoplasia has not been identified in any monkey from this group (Fig. 3a). In contrast, five of the six cases in young-onset control monkeys were considered the cause of death with a mean age at diagnosis of 22.8 ± 1.7 years. Glucoregulatory function was also improved in CR monkeys (Fig. 3a). However, two cases of diabetes have been diagnosed in CR monkeys; thus, the prevention of obesity did not prevent the occurrence of insulin-dependent diabetes and further investigation of the aetiology of such cases is of interest. Interestingly, CR did not reduce the incidence of cardiovascular disease as was reported in the WNPRC colony. Our findings are based on tissue pathology because these diagnoses were identified after death*."
Edited by Michael, 01 September 2012 - 05:58 PM.
Posted 30 August 2012 - 05:36 AM
Posted 30 August 2012 - 09:33 AM
My guess would be that this study suggests that the endogenous antioxidant system in primates is already optimized to the point to where reducing ROS any further via CR isn't going to make much difference, as far as maximum lifespan is concerned anyways.If the CR-induced suppression of cancer was seen in rodents or other cancer-prone animals, might it be the case that CR was correcting a defect in those animals that is taken care of endogenously in the much longer-lived primates?
Posted 30 August 2012 - 10:10 AM
Edited by Michael, 01 September 2012 - 06:02 PM.
Posted 30 August 2012 - 10:36 AM
Posted 30 August 2012 - 10:47 AM
I thought CR was associated with less muscle mass, at least in humans?Lack of activty/exericse might have also played a factor. CR'd males would have mroe muscle mass which might have accounted for better metabolic health, possilbly.
Seems like you're grasping at straws here.The lack of certain changes that are seen in rodents and even in HUMAN studies suggest to me that not just the NIA study had problems (there was also some indications the monkeys were depressed and throwing their food way so the level of CR was decreased between the groups.).
What evidence exists for CR being effective for life extension in humans?The response to CR is far better in the wisconsin study and better still; humans.
Posted 30 August 2012 - 12:45 PM
In those same years, though, studies in mice began indicating there might not be a predictable response to a low-calorie diet. Mice that came from the wild, instead of being born and raised in the lab, did not live longer on low-calorie diets. And in 2009, a study of 41 inbred strains of laboratory mice found that about a third had no response to the diets. Of those that responded, more strains had shorter life spans than had longer ones when they were given less food.
The response to that study was “absolute disbelief,” Dr. Austad said. “Even though the authors are well-respected calorie restrictors, people said the result was not interesting, that there was something weird about the mice.”
Possibly bad new for CR in people on average, given the large genetic diversity in humans. We are probably more analogous to wild-type genetically diverse mice/primates, in which CR does not appear to work on average.
As in inbred rodents, there is possibly a subpopulation of humans for whom CR will work very well, but of course we don't know who they are.
Edited by DLR, 30 August 2012 - 12:49 PM.
Posted 30 August 2012 - 05:20 PM
I think when you consider all the evidence to date, the take-away message is that eating a nutritious diet and staying relatively lean will probably prolong your life, while calorie restriction may or may not. It probably does reduce the risk of specific diseases however. Currently, a number people around the world are restricting their calorie intake in the hope of living longer. I wish these pioneers the best of luck. Hopefully we'll have the answer to this question eventually, but if I were a bettin' man I wouldn't put my money on the idea that calorie restriction will extend lifespan at this point.
Posted 30 August 2012 - 06:52 PM
Posted 30 August 2012 - 10:50 PM
Posted 30 August 2012 - 11:23 PM
Posted 31 August 2012 - 12:30 AM
Didn't mean to single any individual out, actually I seldom even bother visiting those forums/threads (so don't know who is who on there) as I personally don't have the motivation/willpower to follow such a regimen unless there was definitive proof that it would increase maximum lifespan, especially somebody starting it at 50+. I would pop in occasionally to see if there was any new developments however, and was rather amused at some of the self righteous attitudes I would sometimes see. Apparently CR is serious business, while taking supps is child like foolishness to some of those guy, lol. And for what it's worth, I currently don't see any supps out there that have shown any credible evidence that they can lengthen max lifespan either. Res has long been debunked, the buckyball experiment seems flawed, and rapamycyn is too toxic at the effective dosage for humans. Existing supps look promising for increasing healthspan, I remain unconvinced of anything beyond that.You are being slightly unfair to the CRON-crowd. Yes, there are people who overly embrace CR as "proven" means to extend life, but truth to be said, the most vocal proponents as Michael do emphasize the ON component extensively and are certainly not dismissive regarding supps. To the contrary, he has a quite extensively researched regimen which he posted in this forums. On the other hand more speculative supps such as Resveratrol, Rapamacyn or C60 do not exactly have a better scientific basis to warrant their consumption (at least not in real world applications and in primates).
Personally I hope that a positive results of a potential setback would be more interest in supporting biomedical research such as SENS, as sometimes you have the feeling that many CRON people (again, excluding some vocal ones as Michael) are to occupied with their diet, to realize that in the end the will have to rely on it to battle aging, illnes and death.
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