Help
Add Reply
Bookmark
Del.icio.us
Digg
Email
Facebook
Google
Mixx
Reddit
StumbleUpon
Lighter Meals May Bring Longer Life
Monkey study is best evidence yet that fewer daily calories boost lifespan
By Amanda Gardner
HealthDay Reporter
THURSDAY, July 9 (HealthDay News) -- A new study that found that a lower-calorie diet slowed the aging process in monkeys could be the best proof yet that restricted diets might do the same for humans.
"The big question in aging research is, 'Will caloric restriction in species closely related to humans slow aging?'" said Richard Weindruch, senior author of a paper appearing in the July 10 issue of Science. "This is the first clear demonstration that, in a primate species, we're inducing a slowdown of the aging process -- showing increased survival, resistance to disease, less brain atrophy and less muscle loss.
"This predicts humans would respond similarly," added Weindruch, professor of medicine at the University of Wisconsin-Madison and an investigator at the Veterans Hospital in Madison.
Another expert noted that, despite some highly publicized studies in certain species, the link between restricted eating and longer lifespan has been far from proven.
"The idea that dietary restriction extends lifespan in all species is not true. Many strains of rats and mice do not respond. In some strains, it's actually deleterious," explained Felipe Sierra, director of the biology of aging program at the U.S. National Institute on Aging (NIA), which supported the new study. "The fact that it didn't work in some mice but it does seem to work in monkeys is surprising and it gives us hope."
But there's a larger question: how to change humans' increasingly lax eating habits. "This [finding] doesn't give me hope that humans are going to go into dietary restriction," Sierra said.
Another expert agreed. "I think this is wonderful and it has promising benefits but the problem is not that we don't know this stuff, the problem is doing it, is getting people to eat less," added Marianne Grant, a registered dietitian at Texas A&M Health Science Center Coastal Bend Health Education Center in Corpus Christi.
As Sierra sees it, the ultimate value of this and other research like it will be to unveil the physiological mechanisms behind a slowdown in the aging process, and then come up with ways to mimic those processes with drugs or other interventions.
Previous research had shown that calorie restriction can increase survival and stave off many diseases in yeast, worms, flies and, as Sierra pointed out, in some strains of mice.
The new, two-decade-long study ultimately involved 76 rhesus monkeys, all of whom started the study as adults (aged 7 to 14 years). Thirty-three monkeys are still alive, 13 of whom are allowed to eat as they like. The other 20 are allowed a diet with 30 percent fewer calories.
Eighty percent of the original monkeys eating fewer calories are still alive, versus half of those in the control group, the researchers reported.
Among the benefits enjoyed by the lower-calorie group: fewer cancers, less cardiovascular disease, better preserved brain health (especially in regions of the brain involved in motor control and memory) and no diabetes whatsoever, despite this being a common problem in monkeys.
Weindruch said his group is continuing to study the monkeys, a process that could go on for 15 years. Meanwhile, they are collecting a new group of monkeys to more closely study mechanistic processes.
The NIA currently supports a study looking into calorie restriction in humans although, Sierra pointed out, such a study is difficult to conduct.
"Studies in humans can be done but they're not going to address longevity and it's a self-selected group," he said. "Monkeys are the closest we can get."
The findings come a day after U.S. researchers reported in Nature that rapamycin, a drug typically given to transplant patients, significantly extended the lifespans of mice.
SOURCES: Richard Weindruch, Ph.D., professor, medicine, University of Wisconsin-Madison and investigator, Veterans Hospital, Madison, Wis.; Felipe Sierra, Ph.D., director, biology of aging program, U.S. National Institute on Aging; Marianne Grant, registered dietitian, Texas A&M Health Science Center Coastal Bend Health Education Center, Corpus Christi, Texas; July 10, 2009 Science
REAL Primate CR Mortality Data
Results are Getting Strong ...
Rate Topic:
MultiQuote#0 sponsored ad
#2
Posted 09 July 2009 - 06:27 PM
All:
The paper doesn't come out 'till tomorrow; there have been a couple of press leaks, but this is from Science's own website, and cites Weindruch directly:
This is the best of the 3 nonhuman primate studies, and still has some flaws: the actual differnce in Calorie intake has dwindled down to almost zero, because none of the animals are very engaged with their rather monotonous and restricted lives, so the AL eaters aren't finishing their meals a lot of the time; the food isn't the best, nutritionally, and there were definitely some specific nutritional problems (such as excessive retinol, early on) in the diets; we don't really know how how to best care for and feed nonhuman primates, nor how long they can live in captivity, because so few have been studied; and above all, there's evidence that the AL group probably should've been restricted a bit more and the CRed animals restricted even further in turn (no effects on menstruation in the females, and probably some of the AL diabetes is related to modest overweight).
But this is the first solid evidence of a real mortality difference, and it looks substantial.
-Michael
The paper doesn't come out 'till tomorrow; there have been a couple of press leaks, but this is from Science's own website, and cites Weindruch directly:
Quote
Calorie-Counting Monkeys Live Longer
By Michael Torrice
ScienceNOW Daily News
9 July 2009
... monkeys can live to 40, and the average life span is 27 years. Now that the surviving monkeys have reached their mid- to late 20s ... Sixty-three percent of the calorie-restricted animals are still alive compared to only 45% of their free-feeding counterparts. For age-related deaths caused by illnesses such as cardiovascular disease and cancer ... 14 versus five monkeys [have died], respectively. Another seven control and nine lean monkeys died from causes not related to aging such as complications from anesthesia or injuries. Leaner diets also reduced muscle and brain gray matter deterioration, two conditions associated with aging. (The team has not yet studied cognitive differences between the two groups.)
Researchers who study aging are split on how much stock to put in the study. Leonard Guarente ... believes that not enough monkeys have died yet to make definitive comparisons between the two groups. ... On the other hand, molecular biologist Matthew Kaeberlein ... points to the difference in age-related deaths between the two groups as the more relevant statistic. "The fact that they see a significant effect at this point suggests there will be a robust effect when they finish the study," he says.
Weindruch and his collaborators plan to continue monitoring the remaining monkeys, which could stretch the study's length past 3 decades. ...
By Michael Torrice
ScienceNOW Daily News
9 July 2009
... monkeys can live to 40, and the average life span is 27 years. Now that the surviving monkeys have reached their mid- to late 20s ... Sixty-three percent of the calorie-restricted animals are still alive compared to only 45% of their free-feeding counterparts. For age-related deaths caused by illnesses such as cardiovascular disease and cancer ... 14 versus five monkeys [have died], respectively. Another seven control and nine lean monkeys died from causes not related to aging such as complications from anesthesia or injuries. Leaner diets also reduced muscle and brain gray matter deterioration, two conditions associated with aging. (The team has not yet studied cognitive differences between the two groups.)
Researchers who study aging are split on how much stock to put in the study. Leonard Guarente ... believes that not enough monkeys have died yet to make definitive comparisons between the two groups. ... On the other hand, molecular biologist Matthew Kaeberlein ... points to the difference in age-related deaths between the two groups as the more relevant statistic. "The fact that they see a significant effect at this point suggests there will be a robust effect when they finish the study," he says.
Weindruch and his collaborators plan to continue monitoring the remaining monkeys, which could stretch the study's length past 3 decades. ...
This is the best of the 3 nonhuman primate studies, and still has some flaws: the actual differnce in Calorie intake has dwindled down to almost zero, because none of the animals are very engaged with their rather monotonous and restricted lives, so the AL eaters aren't finishing their meals a lot of the time; the food isn't the best, nutritionally, and there were definitely some specific nutritional problems (such as excessive retinol, early on) in the diets; we don't really know how how to best care for and feed nonhuman primates, nor how long they can live in captivity, because so few have been studied; and above all, there's evidence that the AL group probably should've been restricted a bit more and the CRed animals restricted even further in turn (no effects on menstruation in the females, and probably some of the AL diabetes is related to modest overweight).
But this is the first solid evidence of a real mortality difference, and it looks substantial.
-Michael
This post has been edited by Michael: 09 July 2009 - 06:34 PM
Reason for edit: Clarification, fixing link
#3
Posted 09 July 2009 - 07:47 PM
Did any of the researchers expect primate studies to fail given their long lifespan? Aubrey, Phelan?
It does seem very promising to me, and IMO human CR might have a better effect simply because of some of the reasons Michael already mentioned.
It does seem very promising to me, and IMO human CR might have a better effect simply because of some of the reasons Michael already mentioned.
#4
Posted 09 July 2009 - 08:25 PM
Thursday, July 9th 2009 is a historical day for the promotion of life extension:
- Rapamycin [immunosuppressant treatment used in humans] extends old mice lifespan [in specific pathogen free environments]
- CR works in monkeys
We're very close to human life extension treatments!
- Rapamycin [immunosuppressant treatment used in humans] extends old mice lifespan [in specific pathogen free environments]
- CR works in monkeys
We're very close to human life extension treatments!
#5
Posted 10 July 2009 - 01:55 AM
From NYTimes
"Some biologists think it is reasonable to exclude these deaths, but others do not. Steven Austad, an expert on aging at the University of Texas Health Science Center, said some deaths could have been due to caloric restriction, even if they did not seem to be related to aging. “Ultimately the results seem pretty inconclusive at this point,” Dr. Austad said. “I don’t know why they didn’t wait longer to publish.”
"Leonard Guarente, a biologist who studies aging at the Massachusetts Institute of Technology, also had reservations about the findings. “The survival data needs to be fleshed out a little bit more before we can say that caloric restriction extends life in primates,” Dr. Guarente said. In mouse studies, people just count the number of dead animals without asking which deaths might be unrelated to aging, he said."
http://www.nytimes.c...ce/10aging.html
I don't really see any issue when you exclude deaths espsecially from form injuries / accidents, and from anesthesia. I don't see Austad point, there were deaths in both groups from similar things. but there were more accidental deaths in CR monkeys for whatever reason. I think It's totally reasonable to exclude these deaths that are non age related. Whats your thoughts?
I thought this was more of a problem for the NIA studies than the Wisconsin study? I'm not sure, but I think there have been papers reporting the weight differences in the monkeys, and body fat %. There seems to be big differences where if they were eating similar calorie intake now, wouldn't these be now quite similar for both groups?
On the level of CR imposed on the monkeys, I also think it was a sensible idea [even though i believe more CR would have worked better] for them to not restrict severely in case they ran into problems many years later, which could of ended up worse because these kind of life long CR studies haven't been done in primates before. Like you said, the researchers might not know exactly whats best for the monkeys right now, increase the level of CR might of been too much of a risk.
"Some biologists think it is reasonable to exclude these deaths, but others do not. Steven Austad, an expert on aging at the University of Texas Health Science Center, said some deaths could have been due to caloric restriction, even if they did not seem to be related to aging. “Ultimately the results seem pretty inconclusive at this point,” Dr. Austad said. “I don’t know why they didn’t wait longer to publish.”
"Leonard Guarente, a biologist who studies aging at the Massachusetts Institute of Technology, also had reservations about the findings. “The survival data needs to be fleshed out a little bit more before we can say that caloric restriction extends life in primates,” Dr. Guarente said. In mouse studies, people just count the number of dead animals without asking which deaths might be unrelated to aging, he said."
http://www.nytimes.c...ce/10aging.html
I don't really see any issue when you exclude deaths espsecially from form injuries / accidents, and from anesthesia. I don't see Austad point, there were deaths in both groups from similar things. but there were more accidental deaths in CR monkeys for whatever reason. I think It's totally reasonable to exclude these deaths that are non age related. Whats your thoughts?
Quote
the actual differnce in Calorie intake has dwindled down to almost zero
I thought this was more of a problem for the NIA studies than the Wisconsin study? I'm not sure, but I think there have been papers reporting the weight differences in the monkeys, and body fat %. There seems to be big differences where if they were eating similar calorie intake now, wouldn't these be now quite similar for both groups?
On the level of CR imposed on the monkeys, I also think it was a sensible idea [even though i believe more CR would have worked better] for them to not restrict severely in case they ran into problems many years later, which could of ended up worse because these kind of life long CR studies haven't been done in primates before. Like you said, the researchers might not know exactly whats best for the monkeys right now, increase the level of CR might of been too much of a risk.
This post has been edited by Matt: 10 July 2009 - 02:18 AM
#6
Posted 10 July 2009 - 02:11 AM
seems like a very grey issue.
it does kind of bother me a little that the 7 ad lib and 9 CR monkeys dying were excluded. i guess i'd want to know specifically how those monkeys died and if all the others still living experienced the same set of circumstances.
i think you need to look at the data in its entirety, and not allow for the researcher's discretion in deleting deaths from the study. it can be a slippery slope. however, i think you also have to look at the whole set of biological facts, including bloodwork/physical fitness before death and not just the death as a single datapoint.
this issue sort of brings us back the past discussion from the thread re: 'slightly overweight people living longer than thin people." if you get an injury, become immobilized, and have enough body weight/mass so that you can survive and not starve to death until you recover, than maybe the ad lib diet is better than CR.
We live in the real world, not in a sterile lab environment. If you go on CR, exhibit great telomere lengths, but you are frail/fragile and not as durable a person then it may be a trade-off in some regard.
it does kind of bother me a little that the 7 ad lib and 9 CR monkeys dying were excluded. i guess i'd want to know specifically how those monkeys died and if all the others still living experienced the same set of circumstances.
i think you need to look at the data in its entirety, and not allow for the researcher's discretion in deleting deaths from the study. it can be a slippery slope. however, i think you also have to look at the whole set of biological facts, including bloodwork/physical fitness before death and not just the death as a single datapoint.
this issue sort of brings us back the past discussion from the thread re: 'slightly overweight people living longer than thin people." if you get an injury, become immobilized, and have enough body weight/mass so that you can survive and not starve to death until you recover, than maybe the ad lib diet is better than CR.
We live in the real world, not in a sterile lab environment. If you go on CR, exhibit great telomere lengths, but you are frail/fragile and not as durable a person then it may be a trade-off in some regard.
#7
Posted 10 July 2009 - 02:19 AM
Matt, on Jul 10 2009, 01:55 AM, said:
I don't really see any issue when you exclude deaths espsecially from form injuries / accidents, and from anesthesia. I don't see Austad point, there were deaths in both groups from similar thing. It's totally reasonable to exlude these deaths that are non age related. Whats your thoughts?
Well, I think I understand Austad's point; he's suggesting that CR might have been "responsible" for certain of the injuries, accidents, or anesthesia deaths. If CR lead to muscle wasting, maybe that lead to an accident or injury. IMHO this is somewhat far fetched. I think worrying about running the study another decade before publishing is verging on anal retentive. Do they really think that some quirk of primate biology will have the CR group suddenly drop dead in the near future?
#8
Posted 10 July 2009 - 09:12 AM
prophets, on Jul 9 2009, 09:11 PM, said:
seems like a very grey issue.
it does kind of bother me a little that the 7 ad lib and 9 CR monkeys dying were excluded. i guess i'd want to know specifically how those monkeys died and if all the others still living experienced the same set of circumstances.
i think you need to look at the data in its entirety, and not allow for the researcher's discretion in deleting deaths from the study. it can be a slippery slope. however, i think you also have to look at the whole set of biological facts, including bloodwork/physical fitness before death and not just the death as a single datapoint.
this issue sort of brings us back the past discussion from the thread re: 'slightly overweight people living longer than thin people." if you get an injury, become immobilized, and have enough body weight/mass so that you can survive and not starve to death until you recover, than maybe the ad lib diet is better than CR.
We live in the real world, not in a sterile lab environment. If you go on CR, exhibit great telomere lengths, but you are frail/fragile and not as durable a person then it may be a trade-off in some regard.
it does kind of bother me a little that the 7 ad lib and 9 CR monkeys dying were excluded. i guess i'd want to know specifically how those monkeys died and if all the others still living experienced the same set of circumstances.
i think you need to look at the data in its entirety, and not allow for the researcher's discretion in deleting deaths from the study. it can be a slippery slope. however, i think you also have to look at the whole set of biological facts, including bloodwork/physical fitness before death and not just the death as a single datapoint.
this issue sort of brings us back the past discussion from the thread re: 'slightly overweight people living longer than thin people." if you get an injury, become immobilized, and have enough body weight/mass so that you can survive and not starve to death until you recover, than maybe the ad lib diet is better than CR.
We live in the real world, not in a sterile lab environment. If you go on CR, exhibit great telomere lengths, but you are frail/fragile and not as durable a person then it may be a trade-off in some regard.
I'm currently on CR but I also have similar concerns and agree that we live in the real world not in a cage and lab. I've read that after the age of 50 people's immune systems begin to weaken which is why they're more likely to die of infectious diseases compared to younger adults (despite the advancements we've made in antibiotics, etc). CR reduces the white blood cell count and I'm concerned how that would affect the elderly with an already weakening immune system.
The reason I'm on CR despite the possible problems are that it has helped improve my health; I'm also young and many of the concerns I hold would not begin to affect me for few more decades.
#9
Posted 10 July 2009 - 06:56 PM
Here is the paper 
:
Caloric Restriction Delays Disease Onset and Mortality in Rhesus Monkeys
Ricki J. Colman, Rozalyn M. Anderson, Sterling C. Johnson, Erik K. Kastman, Kristopher J. Kosmatka, T. Mark Beasley, David B. Allison, Christina Cruzen, Heather A. Simmons, Joseph W. Kemnitz, and Richard Weindruch
Science 10 July 2009: 201-204.
Journal pre-amble: Age-associated death and onset of pathologies are delayed by controlled caloric restriction, thus prolonging life span.
Abstract
Caloric restriction (CR), without malnutrition, delays aging and extends life span in diverse species; however, its effect on resistance to illness and mortality in primates has not been clearly established. We report findings of a 20-year longitudinal adult-onset CR study in rhesus monkeys aimed at filling this critical gap in aging research. In a population of rhesus macaques maintained at the Wisconsin National Primate Research Center, moderate CR lowered the incidence of aging-related deaths. At the time point reported, 50% of control fed animals survived as compared with 80% of the CR animals. Furthermore, CR delayed the onset of age-associated pathologies. Specifically, CR reduced the incidence of diabetes, cancer, cardiovascular disease, and brain atrophy. These data demonstrate that CR slows aging in a primate species. Evidence that mammalian longevity could be increased emerged in 1935 in a rodent study showing that caloric restriction (CR), without malnutrition, extended average and maximum life span and delayed the onset of age-associated pathologies (1). It was not until the 1990s that CR became widely viewed as a scientific model that could provide insights into the retardation of the aging process (2) and thereby identify underlying mechanisms of aging (3). The inverse relationship between calorie intake and increase in life span in mice suggests a role for regulators of energy metabolism in the mechanism of CR. Accordingly, CR-induced metabolic reprogramming may be a key event in the mechanism of life span extension (4). Studies in yeast, worms, flies, and mice point to a role for nutrient-responsive signaling molecules, including SIRT1, mTOR, and PGC-1, in aging and CR (5). The relevance of these findings for human aging depends on the conservation of the effects of CR on aging in primates.
:Caloric Restriction Delays Disease Onset and Mortality in Rhesus Monkeys
Ricki J. Colman, Rozalyn M. Anderson, Sterling C. Johnson, Erik K. Kastman, Kristopher J. Kosmatka, T. Mark Beasley, David B. Allison, Christina Cruzen, Heather A. Simmons, Joseph W. Kemnitz, and Richard Weindruch
Science 10 July 2009: 201-204.
Journal pre-amble: Age-associated death and onset of pathologies are delayed by controlled caloric restriction, thus prolonging life span.
Abstract
Caloric restriction (CR), without malnutrition, delays aging and extends life span in diverse species; however, its effect on resistance to illness and mortality in primates has not been clearly established. We report findings of a 20-year longitudinal adult-onset CR study in rhesus monkeys aimed at filling this critical gap in aging research. In a population of rhesus macaques maintained at the Wisconsin National Primate Research Center, moderate CR lowered the incidence of aging-related deaths. At the time point reported, 50% of control fed animals survived as compared with 80% of the CR animals. Furthermore, CR delayed the onset of age-associated pathologies. Specifically, CR reduced the incidence of diabetes, cancer, cardiovascular disease, and brain atrophy. These data demonstrate that CR slows aging in a primate species. Evidence that mammalian longevity could be increased emerged in 1935 in a rodent study showing that caloric restriction (CR), without malnutrition, extended average and maximum life span and delayed the onset of age-associated pathologies (1). It was not until the 1990s that CR became widely viewed as a scientific model that could provide insights into the retardation of the aging process (2) and thereby identify underlying mechanisms of aging (3). The inverse relationship between calorie intake and increase in life span in mice suggests a role for regulators of energy metabolism in the mechanism of CR. Accordingly, CR-induced metabolic reprogramming may be a key event in the mechanism of life span extension (4). Studies in yeast, worms, flies, and mice point to a role for nutrient-responsive signaling molecules, including SIRT1, mTOR, and PGC-1, in aging and CR (5). The relevance of these findings for human aging depends on the conservation of the effects of CR on aging in primates.
This post has been edited by Michael: 10 July 2009 - 08:53 PM
Reason for edit: Moved to Member's Area for ©
#10
Posted 10 July 2009 - 07:02 PM
There will be more results from this study, it could be up to 15 years till the last CR'd rhesus dies. I was happy to hear from my husband that CR was in the news, as he reads CNN and major news sites daily--that this study is making the rounds on AP is wonderful. The New York Times article along will likely increase sales of CR books and hits on CR sites
#11
Posted 10 July 2009 - 07:33 PM
I saw this at the newspaper stand today. I forget which one I saw it on the cover of.
This is another great example of the little successes that are piling up and getting ready to give rise to wider, more in depth, coverage of the whole cause.
This is another great example of the little successes that are piling up and getting ready to give rise to wider, more in depth, coverage of the whole cause.
#12
Posted 10 July 2009 - 08:27 PM
Nice new pic released of another two monkeys that are asme age but as usual, CR one looks younger and still has a nice coat
http://img.photobucket.com/albums/v141/who.../cr_monkeys.jpg
and a new pic of canto and owen 2 + years later (high res)
http://img.photobucket.com/albums/v141/who...sComparison.jpg
http://img.photobucket.com/albums/v141/who.../cr_monkeys.jpg
and a new pic of canto and owen 2 + years later (high res)
http://img.photobucket.com/albums/v141/who...sComparison.jpg
This post has been edited by Matt: 16 July 2009 - 01:32 AM
#13
Posted 10 July 2009 - 08:31 PM
niner, on Jul 9 2009, 10:19 PM, said:
I think worrying about running the study another decade before publishing is verging on anal retentive. Do they really think that some quirk of primate biology will have the CR group suddenly drop dead in the near future?
Unfortunately, that could very well happen. At least it could happen with your run-off-the-mill intervention. We have seen dozens of stubstances that decreased early life mortality and increased average life span in rodents just to see them head towards 0% survival as quickly as the placebo group. Species maximum life span is a tough enemy and such studies get interesting only in the end. First, they have to prove that it will extend maximal life span. Going off the rodent data most people expect it to happen (proof is still required, we're scientists and pretty careful people after all), but even more important is to find out about the magnitude of the effect. Does it work better or worse in primates? Are there diminishing returns? Does it slow all kinds of age-related pathologies in primates?
#14
Posted 10 July 2009 - 09:02 PM
kismet, on Jul 10 2009, 08:31 PM, said:
Unfortunately, that could very well happen. At least it could happen with your run-off-the-mill intervention. We have seen dozens of stubstances that decreased early life mortality and increased average life span in rodents just to see them head towards 0% survival as quickly as the placebo group. Species maximum life span is a tough enemy and such studies get interesting only in the end. First, they have to prove that it will extend maximal life span. Going off the rodent data most people expect it to happen (proof is still required, we're scientists and pretty careful people after all), but even more important is to find out about the magnitude of the effect. Does it work better or worse in primates? Are there diminishing returns? Does it slow all kinds of age-related pathologies in primates?
These are very good points, and I wouldn't advise stopping the study now. I do think it's reasonable to publish now, and again later as they have statistically significant results. It might be different if CR hadn't already been successfully applied to numerous other species.
#15
Posted 11 July 2009 - 12:52 AM
prophets, on Jul 9 2009, 09:11 PM, said:
seems like a very grey issue.
it does kind of bother me a little that the 7 ad lib and 9 CR monkeys dying were excluded. i guess i'd want to know specifically how those monkeys died and if all the others still living experienced the same set of circumstances.
i think you need to look at the data in its entirety, and not allow for the researcher's discretion in deleting deaths from the study. it can be a slippery slope. however, i think you also have to look at the whole set of biological facts, including bloodwork/physical fitness before death and not just the death as a single datapoint.
this issue sort of brings us back the past discussion from the thread re: 'slightly overweight people living longer than thin people." if you get an injury, become immobilized, and have enough body weight/mass so that you can survive and not starve to death until you recover, than maybe the ad lib diet is better than CR.
We live in the real world, not in a sterile lab environment. If you go on CR, exhibit great telomere lengths, but you are frail/fragile and not as durable a person then it may be a trade-off in some regard.
it does kind of bother me a little that the 7 ad lib and 9 CR monkeys dying were excluded. i guess i'd want to know specifically how those monkeys died and if all the others still living experienced the same set of circumstances.
i think you need to look at the data in its entirety, and not allow for the researcher's discretion in deleting deaths from the study. it can be a slippery slope. however, i think you also have to look at the whole set of biological facts, including bloodwork/physical fitness before death and not just the death as a single datapoint.
this issue sort of brings us back the past discussion from the thread re: 'slightly overweight people living longer than thin people." if you get an injury, become immobilized, and have enough body weight/mass so that you can survive and not starve to death until you recover, than maybe the ad lib diet is better than CR.
We live in the real world, not in a sterile lab environment. If you go on CR, exhibit great telomere lengths, but you are frail/fragile and not as durable a person then it may be a trade-off in some regard.
I couldn't have said it better myself. The accidental deaths DO MATTER. Frailty leads to immobility which leads to death (in humans). There is also the curious matter that slightly pudgy humans live longer - which again might have to do with the fact that they have a reserve energy store to help them make it through a time of injury or infection. Still, this is a great result for lab/controlled longevity. Barring injuries and infection, CR "takes the cake" for retarding most aging pathways.
#16
Posted 11 July 2009 - 02:38 AM
Mind, on Jul 11 2009, 01:52 AM, said:
I couldn't have said it better myself. The accidental deaths DO MATTER. Frailty leads to immobility which leads to death (in humans)
Although I believe the majority (if not all) deaths from accidents occured very early on in the study. Will have to try and confirm this. Most of the issues with anesthesia, gastric bloat, and accidents (head trauma i believe) were able to be more controlled further into the study.
Accident is an accident, it doesn't tell you about if or not aging is slowed down. It has to be factored out. Maybe this comes down to a personal decision on whcih survival curve / data you want to take notice of. For me i'm happy taking more notice of the age related one. Anesthesia also, i believe the monkeys get put under 1-2 times a year. This should definitely be excluded. For me these seem perfectly reasonable and i'm happy they supplied both data.
This post has been edited by Matt: 11 July 2009 - 02:39 AM
#17
Posted 14 July 2009 - 11:02 PM
Just finished off a blog post on the primate study if anyone interested in checking it out http://matts-cr.blogspot.com/
#18
Posted 15 July 2009 - 04:54 AM
Calorie restrictive eating for longer life? The story we didn’t hear in the news
This blog post brought up the issue prophet mentioned. It also mentioned that the control monkeys were overfed by 20% compared to normal.
It also mentioned Aubrey de Grey's criticism of CR. I remember there being a response from Michael to Aubrey's criticism, could someone point me in the right direction.
It's great that this study is being done so that the genetic expression could maybe be mimicked by pharmaceuticals but in real life I would rather not try caloric restriction.
This blog post brought up the issue prophet mentioned. It also mentioned that the control monkeys were overfed by 20% compared to normal.
Quote
Since 1989, we have been studying the effects of a moderate (30%) adult-onset dietary restriction (DR) in a nonhuman primate model. We chose a rhesus monkey (Macaca mulatta) model… The effects of aging and DR are being analyzed longitudinally in adult male rhesus monkeys, ranging in age from 8 to 14 years (average 9.3 years) at study onset… The 30 rhesus monkeys used in this study were born at and have lived their entire lives at the Wisconsin National Primate Research Center… [In 1994, an additional 30 females and 16 males were added to the study.] Prior to the start of the study, animals were monitored for individual baseline food intakes of a purified diet (10% fat, 15% protein) for 3 months. Animals were then randomized to either Control or Calorie Restricted groups based on their baseline food intakes. Food allotments for the CR animals were then reduced by 10% per month for 3 months to reach the intended 30% DR. Control animals were fed 20% more than their average daily intake…
It also mentioned Aubrey de Grey's criticism of CR. I remember there being a response from Michael to Aubrey's criticism, could someone point me in the right direction.
It's great that this study is being done so that the genetic expression could maybe be mimicked by pharmaceuticals but in real life I would rather not try caloric restriction.
#19
Posted 15 July 2009 - 11:11 AM
imo, her article is excessively critical.
She seems to have this very narrow, negative agenda at the outset. "This is all bad." There are clearly some positives associated with CR, as evidenced by the biomarkers. I've no idea how this one paper can find "aggressive behavior" in CR practitioners, when they exhibit better vascular biomarkers. Also, I thought most CR practitioners had slightly lower testosterone.
If I can recall, MR's response to Aubrey was something along the lines of: "Aubrey has no data. CR has practical data behind it. Show me the data otherwise."
It may very well come down to the fact that the population used in the primate study was too low to generate a statistically significant result. It's unfortunate for now. It may eventually generate one later. I'm sure these guys live and breathe this research as their life. When you suffer the consequences of a 15-20 year experiment that wasn't set up quite right in the first place (1. not enough animals and 2. giving 20% extra calories to the 'control' group), it's a shame.
I'm sure if scientists proposed a diet with 2500 calories per day but a higher level of exercise (a normal amount of calories, but burned off through exercise), people might not look at it as an oddity.
There are also very significant epigenetic components involved in any diet. From the womb through the first two years of life, we are all programmed metabolically. It may explain why CR does not agree with some people. I think the concept of LifeGen and the gene chip assay, is actually quite promising.
I'd really like to see a DEXA scan of these primates, to see if CR is depriving the monkeys from bone over the years. If you are losing bone mass with CR, then your risk of falling and being injured (breaking a hip, etc.) is much higher.
She seems to have this very narrow, negative agenda at the outset. "This is all bad." There are clearly some positives associated with CR, as evidenced by the biomarkers. I've no idea how this one paper can find "aggressive behavior" in CR practitioners, when they exhibit better vascular biomarkers. Also, I thought most CR practitioners had slightly lower testosterone.
If I can recall, MR's response to Aubrey was something along the lines of: "Aubrey has no data. CR has practical data behind it. Show me the data otherwise."
It may very well come down to the fact that the population used in the primate study was too low to generate a statistically significant result. It's unfortunate for now. It may eventually generate one later. I'm sure these guys live and breathe this research as their life. When you suffer the consequences of a 15-20 year experiment that wasn't set up quite right in the first place (1. not enough animals and 2. giving 20% extra calories to the 'control' group), it's a shame.
I'm sure if scientists proposed a diet with 2500 calories per day but a higher level of exercise (a normal amount of calories, but burned off through exercise), people might not look at it as an oddity.
There are also very significant epigenetic components involved in any diet. From the womb through the first two years of life, we are all programmed metabolically. It may explain why CR does not agree with some people. I think the concept of LifeGen and the gene chip assay, is actually quite promising.
I'd really like to see a DEXA scan of these primates, to see if CR is depriving the monkeys from bone over the years. If you are losing bone mass with CR, then your risk of falling and being injured (breaking a hip, etc.) is much higher.
This post has been edited by prophets: 15 July 2009 - 11:32 AM
#0 sponsored ad
#20
Posted 15 July 2009 - 12:28 PM
Quote
This blog post brought up the issue prophet mentioned. It also mentioned that the control monkeys were overfed by 20% compared to normal.
No I don't believe this is true, the ad lib intake was also not 'true' ad lib and they had their food taken away from them. As with proctols in other animals I believe the control group were also restricted to try and prevent obesity.
Quote
It also mentioned Aubrey de Grey's criticism of CR. I remember there being a response from Michael to Aubrey's criticism, could someone point me in the right direction.
Yea I can send it to you if you want
She also says in her blog
Quote
The non-aging-related causes of death included monkeys who died while taking blood samples under anesthesia, from injuries or from infections, such as gastritis and endometriosis.
The monkeys did not die from infections or gastritis. They mostly died for PREVENTABLE causes if more care was taken. i.e Not overcooking batch of food and killing the monkeys from gastric bloat, duh.
and look how the way she words this one'
Quote
As the supplemental data explains, 16 deaths from “non-age-associated causes were censored and their age of death used as the time variable in the regression.
She words it so the average reader without looking more into it would probably assume these 16 deaths were all from the CR group.
she goes on to say
Quote
but they could realistically be adverse effects of prolonged calorie restrictions on the animals’ health, their immune system, ability to handle stress, physical agility, cognition or behavior.
Well no there is no data that supports immune systems were weakened in monkeys, they never died from infections, CR animals usually are able to withstand greater stress, the CR monkeys were reported to be in better shape physically, as you can see by their posture and the way they move on video, and in terms of cognition, it seems the CR monkeys are doing better. Not much behaviour differences were noted in the papers on the primates.
she goes on to say
Quote
the control animals were overfed 20% more than their usual diet, while the CR monkeys’ diets were adjusted to keep them about 30% less than the control monkeys.
I think this is rubbish, the control group were not as I recall fed 20% more than their ad lib intake, she doesn't supply any references for this, then she assumes that the CR monkeys were fed 10% less to achieve a 30% reduction in calories? Each CR monkey had its baseline intake calculated and reduced by 10% each month until reaching 30% below its normal calorie intake.
This post has been edited by Matt: 15 July 2009 - 01:53 PM
Share this topic:
Fast Reply
1 User(s) are reading this topic
0 members, 1 guests, 0 anonymous users
Loading