I've heard a talk recently by a guy who works with scientists who do calorie restriction experiments.
What he said is an eye-opener. The animals look healthier but they don't live longer. They don't seem to die of age, but they do just drop dead one day, not always from any obvious cause at all - although they seem particularly susceptible to infections.
His hypothesis was that calorie restriction works by forcing the body on such low resources it has to cannibalize itself, which has the advantage it cleans up age-related crud much more effectively - and the disadvantage that there is absolutely no slack in the system. Every problem is a crisis.
Health nuts are going to feel stupid someday, lying in hospitals dying of nothing.
--Redd Foxx
Being one of those Health Nuts, I practice CR during the weekdays, and let my self go (relatively) on the weekends, I'd recommend that anyone try it for a month. The first week is the hardest, but you will feel a lot more in tune w/ your body.
Slack = various sorts of resources, including immune resources.
Crud = inter- and intra-cellular unwanted buildup of proteins, failing cells, non-reversible damage, yadda yadda. It all gets torn up and coincidentally cleaned up by the body's panic for materiel.
If that's the case, intermittent fasting seems like it should produce similar effects to CR. I wait with bated breath for the experiment that does intermittent CR on mice. :)
Why the downvotes? It's absolutely true. "I heard something" is not a proper argument, and the claim that CR has no effect on lifetime is at odds with everything I've heard on the matter. One of my friends (Chemistry PhD) is crazy about the subject, has read all the studies and he's very excited about the insight CR discoveries may bring.
So .. harsh but fair. Anecdotes are worthless. Source please. And cdr should be rewarded, not punished, for calling it out.
It would be a terrible way to write an academic paper - which I'm not doing, I'm just mentioning the content of a related talk I'd heard. Please avail yourself of the primary sources.
"Weindruch and his collaborators plan to continue monitoring the remaining monkeys, which could stretch the study's length past 3 decades. "If we reach the 40-year-old life span, the study could continue for another 15 years," Weindruch said."
The NY Times article says:
“Ultimately the results seem pretty inconclusive at this point,” Dr. Austad said. “I don’t know why they didn’t wait longer to publish.”
So, I think it is too early to draw any conclusions about longevity. Though, it does seem prudent to note the reduced rate of diabetes, cancer, and heart/brain disease in monkeys with reduced caloric intake.
I don't see how prudent it is. What can I do with that information, given the rest of the results of the study?
I don't have anything against diabetes, cancer or heart/brain disease per se. It's not as if, when I die from an infection or pneumonia, I'll congratulate myself that it wasn't cancer!
I guess what I'm trying to say is that, if you consider it "prudent to note the reduced rate of diabetes, cancer, and heart/brain disease", then my response is it's just precisely as prudent to note the increase in non-diabetes, cancer, and heart/brain disease related deaths.
Sure, it may be reducing the causes of some diseases, but if it isn't improving the overall life span of the monkeys or their quality of life it has very limited application.
Perhaps it will turn out that those with a restricted diet who make it through the first 30 years make it through the next 40 as long as they don't fall and break their osteoperotic bones or get exposed to a disease.
As it currently stands, the study is showing no difference. Sitting around for another 25 years on the hope that the trend might change sounds a bit like unfounded faith to me.
Basically, rhesus monkeys on a restricted calorie diet only lived longer if you remove "non-aging related deaths".
But some of those deaths (eg, dying under anesthesia during a blood test) could have links to their diet, so removing them is just withdrawing non-supporting evidence to prove your (pharma-funded) hypothesis.
In other news, riding your bike to work is considered safer than driving a car ... once we remove those cases of bike-riders killed in car collisions.
Replace that with could have been caused by aliens to see how ridiculous that sort of claim is. There is no reason to suppose that dying under anesthesia is related to the diet.
Also your analogy doesn't make any sense. Perhaps if they removed bikers that died in traffic accidents while not riding a bike. And then you could argue 'bikers behave differently in traffic, so perhaps biking was the cause'... yeah, and perhaps we should also take the phase of the moon into account, just to be sure...
I haven't read the studies. Still, why isn't it reasonable to think that a monkey that eats too little will die more readily under stress? You can remove clearly unrelated causes (e.g. monkeys run over by bicyclists), but it's not nearly so clear for anesthesia.
Define 'stress', especially for these animals. Wouldn't you think that living in a laboratory cage is 'stressful'? If that's the daily baseline, I can't see how 'stress' can be a catchall explanation for even borderline cases. Administering anesthesia is a form of surgery. Even if they're related, would you want to say that death during surgery is a form of aging?
More importantly, deaths are just one of the variables being measured. The diet seems to improve quality of life, not just raw quantity. That's reason enough to be interested in these findings.
Furthermore, the author of this blog seems to doubt the role of Science in publishing these findings. The money they make has no bearing on the results. Other scientists, doing closely related work, reviewed the work in excruciating detail (read the footnotes, not the press releases) and found its clear scientific value. Sure, blame the media for the headlines. But the work, as a status report on the field, is very encouraging.
Because the monkeys weren't being underfed and it's a straw man to suggest they were. Tibetan monks get by on much less food than we do and they will still kick our asses anytime.
You're assuming that a monkey that eats 20% less than a monkey that's given the choice to eat as much as it wants necessarily isn't underfed? Maybe. But without some other research that I've missed, that really begs the question.
I think anyone living in a western country has enough data to realize that people eating a western diet tend to be overfed, so the comparison between westerners and Tibetan monks has little to do with monkeys.
In the caloric restriction experiments, the nutritional density of the food the animals are fed is almost always increased. Fewer calories, same levels of protein, nutrients, etc. It's not just a matter of 'less'.
From what I've read, humans on caloric restriction diets have to design their diets carefully, to increase the nutritional density of their own food supply. (E.g. http://www.calorierestriction.org/Getting_started)
Do you really think your casual pondering of the matter has revealed an insight not obvious to the experienced, professional scientists who designed and are now running this large scale, multi-decade experiment?
It beggars belief they have not considered, and painstakingly controlled for, such factors.
> There is no reason to suppose that dying under anesthesia is related to the diet.
If monkeys in one group were more likely to die under anesthesia than monkeys in a different group, I'd suspect that something is going on. (Being unimaginative, I'd exclude the possibility that dying under anesthesia causes a low calorie diet.)
If two monkeys in one group died under anesthesia, that doesn't constitute ground to conclude they were more likely to die: it is simply not statistically significant. Hence you may subtract them from the age related deaths.
> If two monkeys in one group died under anesthesia, that doesn't constitute ground to conclude they were more likely to die
I didn't say that two monkeys constituted statistical significance.
> Hence you may subtract them from the age related deaths.
You can subtract them because they're not statistically significant, but you can't conclude that there isn't something going on, which is what "there's no reason to suppose" means.
Suppose that odds of death due to anesthesia is really low (which it is) but that calorie restriction increased it by 10x (which we don't know either way). 10x a really small number is small enough that this study can't observe the effect because it doesn't kill enough monkeys. And yet, that 10x can easily cause two deaths in one pool while the other has 0.
I think his point would be best supported by the note that the study has not found a statistically significant difference in mortality between the restricted and unrestricted diets. It found that aging-related causes of death (cancer and heart disease) were reduced by a factor of three. This implies that the calorie restricted monkeys had higher-than-control rates of mortality due to non-aging effects, such as anesthesia and disease.
I take issue with much of what was said in this article. Many, if not all of the examples the author refers to are explicit in there statements and not being vague. Additionally, the results of the studies are available for review and carefully explain the reasons why some deaths were not inluded in the results.
The author is picking apart chosen pieces of text and apparently has not read the actual study results.
Agreed. I stopped reading when the author got into a snit because "Control animals were fed 20% more than their average daily intake". It seems clear from context that that was to allow the animals to eat as much as they wanted, the animals were not force-fed 20% more. They're given extra food in case they feel extra hungry that day. It's standard in caloric restriction experiments to feed one group of animals ad libitum, and the other group, some fraction of the ad libitum rate. The effect of caloric restriction on life span has been known for decades, well before it penetrated the mainstream consciousness, and has been described for many different species under many different experimental regimes. It's a robust effect, and a mysterious one.
This article smacks of 9/11 truther, anti-evolution froth. The author has an agenda and she'll pound on her podium until she bludgeons us into agreement that all science infrastructure is corrupt and nothing we read could possibly be true.
Admittedly, there's a lot of junk science out there, and the authors of this study could have waited another 10 years before reporting any results. But put yourself in their shoes: you're starting to see an effect. Every time you go to a conference, people say, "So, how's that multidecade experiment of yours going?" So why not report what you see, and publish another paper in 10 years? It doesn't have to be a conspiracy. Really.
The problem is that in ten years there will still be many unanswered questions. Science is a series of progress reports. They chose to publish and their peers agreed that the work was publishable.
On food availability: many animals, such as mice and dogs, are less able to restrain their own diet and will overeat if allowed to do so. This would lead to the control group overeating, not eating only the number of calories they need, and increasing their chance of obesity-related death. I think a better study might have given the control group the expected number of calories they would require, then significantly restricted the test group.
This study also did not support that calorie restriction increases lifespan, like you do. No study has been able to do that yet. All the studies have been able to do is show that laboratory animals can live longer with a restricted calorie diet. There are many variables controlled for in those studies which are not controlled for in the general human population.
Do you get more exercise than simply sitting in your bedroom all day? If so you do not match the studies.
Do you interact with people outside your home or do people ever come into your home? If so you do not match the studies.
Were you bred for laboratory study? If not you do not match the studies.
No one has show that calorie restrictive diets have worked in humans yet. Evidence is the best studies, like this one, have not been able to show a statistically significant difference in life span.
What are you talking about? He linked to the study and priced it out for you, but he didn't read it? The article compared the actual findings of the study with what was reported in the media and press releases.
I don't care how careful they were in explaining why they vacated many of the deaths; if you're trying to show that monkeys live longer on calorie restricted diets, you can't do that. At least, you can't if you want to convince me or most rational people.
More importantly, you can't let the media go and publish that you found something when you didn't.
That, particularly, is what makes this junk science. The data isn't necessarily incorrect or contaminated, but we have to be careful not to over-generalize the findings.
There are too many factors not accounted for in this study to apply it to general use in humans. My favorite example is that laboratory colonies are isolated from many pathogens, and thus they exclude disease interaction. In most studies this is desired, but in a whole-life study like this it cannot be ignored if it will be applied to people out in the wild.
This study can only be used to think about this specific effect on aging in isolation and look for mechanisms which we can then test in the general population.
There was a recent study online, about how moderately overweight people have a slightly lower mortality rate than those with "normal" weight. The problems are with the morbidly obese end of the spectrum.
I can't find the study (anyone recall it?), but it seems compatible with the implication of this submission, that while being overweight might increase "age-related" deaths, it protects you against the others.
One of the few negative things about the growth of the internet is how much people rely on it for health information. Sometimes I think they'd be better off flipping a coin.
I don't know if its just me who's noticed this, but if one pans out and takes an overview of the main diet fads over the past 30 years, one will notice that the main focus of a diet changes every 10 years or so.
Recall in the 90's when everything was "low-fat". Starting somewhere in the 2000's the health industry switched it over to "low-carbs".
In the 80's, if one wanted to build muscle they were told to eat as many carbs as possible. Nowadays one is supposed to eat as much protein as possible.
This is just diet information. Methods of exercise change too. In fact, they sort of cycle in a way.
Ever feel like the health industry is trying to pull one over on you?
In general I'd support that we have medical professionals to make these decisions for us. I would prefer to have someone I trust, is well educated on the subject, and keeps up with the literature who can point me in the right direction. One result of the specialization in our society and our inability to stay on top of every subject that affects our lives, is that no one can make a truly informed claim on every life decision.
Sadly, many health practitioners are less motivated by science and more motivated by process. They stop educating themselves after they have finished their residency equivalent. Once they are in charge of medical decisions they are bombarded with marketing, which has the goal of selling products, not necessarily with helping anyone.
At this point, I don't know who to trust for medical advice.
I do not know what I am talking about when it comes to this topic. Neither, it seems, do most others here. We are intelligent laymen, but laymen all the same. So what do we do in order to intelligently judge this blog post?
Well, first, let's consider what we know about the contenders. On one side, a number of respected professional scientists conducting a very expensive multi-decade study and publishing the results in peer-reviewed journals. On the other side, a nurse with a Blogspot blog.
OK, that is not necessarily bad. Great truths have been spoken by nobodies. We judge by the message, not the speaker.
But still, we need more "meta" information. Studies appearing in peer reviewed journals are assumed to be reliable because of the good history of the journal. Let's try to ascertain the reliability of this source, looking at her history - and maybe we'll find some other things she discusses that we do know something about, so we can match up her worldview to ours.
And ... oh dear. Let's look at this blog, shall we? I'll ignore the warning sign of the 20+ links to "fat support" groups in the blogroll. Maybe she's just supportive of her large readers. Maybe she doesn't have an agenda? Benefit of the doubt and all that.
Oh, another long (LONG) article in which she completely demolishes another study, this time about the "obesity paradox" - being slightly overweight was associated with a slight increase in health. She claims that in fact the study shows that overweight and obese people are much healthier than the media reported, and they were covering it up.
Hm. She takes two major studies to pieces in as many posts. That's unusual, for not one but TWO studies to be completely wrong, in a short amount of time, and one person - her - to be the one to find where they are wrong. And both wrong, as it happens, in favour of eating.
Are you getting suspicious yet?
Let's move further down the first page of her blog. Ooh, a post in which she cherry picks a couple of bad examples of govt. health care to make an unsubtle point about the planned health reforms in America. Completely ignores that every other developed country has socialised health care and we do fine - plus live longer (which we shouldn't, since fat people have an advantage, apparently!).
I am beginning to smell a crank.
I make it down to "Pudge Police are coming (Part 2)" before calling it quits.
Still treating this article as something worth your time?
I was entertained by your fact-finding mission. I only skimmed the original diatribe.
Still, the fact that deaths were removed from the data at all (exactly in favor of the pet hypothesis of the researchers) because they "didn't count" is extremely suspicious, even if it may prove justified (by other confirming studies).
This is pure speculative thought, but I feel the crux of the problem may be in the tests to determine the caloric load of foods/drinks - they literally just set it on fire, with the fundamental reason being, this is more or less how our body draws energy from what we consume. I could be wrong, but I feel as though my insides constitute something much more intricate and complicated than a furnace. As I see it, the problem lies in our methods of determining the respective energy potential/composition of a given food - the problem may be with the standard of measure, not a method of dietary restriction.
Are you serious? How about this part right here in the study title:
Caloric Restriction DELAYS Disease Onset AND MORTALITY in Rhesus Monkeys
...combined with the fact that in the contents of the study you link to, they eliminate significant data points whose presence would contradict the claimed delay in mortality.
I guess we'll all have to judge for ourselves whether it's fair to eliminate a bunch of deaths other than for exceedingly obvious reasons, e.g., someone breaks into the lab and kills the monkeys. I know which side I'm on.
What he said is an eye-opener. The animals look healthier but they don't live longer. They don't seem to die of age, but they do just drop dead one day, not always from any obvious cause at all - although they seem particularly susceptible to infections.
His hypothesis was that calorie restriction works by forcing the body on such low resources it has to cannibalize itself, which has the advantage it cleans up age-related crud much more effectively - and the disadvantage that there is absolutely no slack in the system. Every problem is a crisis.