There is a lot of evidence beginning to emerge on the value of fasting. This was once encoded in culture as almost every culture had some concept of fasting. We lost so much knowledge when we let nutrition "science"[1] completely overwhelm the wisdom of our ancestors.
On a personal note, I found fasting became much easier after I changed my diet to be ketogenic. With a metabolism primed for burning fat for energy and not subject to a blood sugar roller coaster, going a couple days without food is more of a mental challenge than physical hunger.
1. We've acted like nutrition can give the same cut and dry answers that physics has, and the health of our population shows how well that has worked. Worse, nutrition seems to be driven by egos and media in a way that is nothing short of frightening.
>health of our population shows how well that has worked
The average lifespan has gone up considerably in recent decades, and people remain active longer than ever, i.e. people are gaining productive years, not just end-of-life years.
> There is a lot of evidence beginning to emerge on the value of fasting. This was once encoded in culture as almost every culture had some concept of fasting.
This is a cultural rift between Western Europe and everyone else. I grew up in Eastern Europe (now I live in the US), and fasting was not an extraordinary concept in that culture, by any means. But I keep noticing how controversial it is in the West.
I could probably speculate on the influence of material wealth on culture, and so on, but there's probably not much of a point here.
> I found fasting became much easier after I changed my diet to be ketogenic.
You don't need to go that far. Fasting is easy when you don't do any kind of alimentary excess in general.
I think the whole keto concept is just the pendulum swinging all the way to the other side. I guess it will settle in the middle at some point. Eat a bit of everything, nothing in excess, make sure to not miss the greens and the fruits, etc. Self-control and self-limiting are things that we all need to re-train ourselves for - and not just when it comes to food.
---
Anyway, I'm far more interested in studies regarding the effects of fasting on the brain. Traditionally, it was used in a spiritual context, by people who, for lack of a better term, were consciousness hackers. Fasting seemed to enable that process, whatever the mechanism.
I'm also very curious about the effects of fasting, if any, on neurodegenerative diseases.
Beware of pseudoscience. In the past, some things worked, something things didn't, but there's no understanding as to why they did or didn't work out of traditional models.
Scientific models haven't been all that great either, but science hopefully will eventually self correct as nutritional models become more sophisticated. If there is light at the end of the tunnel it will be because of the eventual understanding that the scientific method provides, not reverting back to traditional models.
Traditional models don't self correct and there are plenty of instances of people consuming outright poisons under such systems or people following traditional nutrition models finding themselves surrounded by an abundance of previously rare foods that the modern food supply system easily provides, and practically gorging themselves on it to negative health results.
As if our ancestors were fasting because they knew it was good for their health. As if their poor nutrition didn't cause much worse problems for them like nutrient deficiencies, lower IQ, shorter heights, lower life expectancies. As if most people today eat only according to the best consensus of nutrition science.
I can second that. Ketosis and fat adaption reduces the need for constant refueling. I have no problem going 24 hours between meals and exercising while fasting.
I typically eat ~12 meals per week, 2000 kcal per meal.
In addition, the consistent mental acuity achieved in ketosis is fantastic.
While science is advancing and giving a better view of what is needed and what can cause problems, the market is replacing most things in the food without much regard for its consequences
Also, science "doesn't know what it doesn't know yet", so we may be missing something that was inconspicuously removed, or suffering from something that was apparently safe
I think it's important to note that "Ketogenic" might not be the right word for the necessary diet intervention to make it easier to fast for long periods.
Ketosis is a state where you eat so little carbohydrate, that your body is forced to create "ketone bodies" to fuel the brain. This typically happens at <50g/day carbohydrate.
Most anecdotal evidence (and my own experiences) show that you can get your body into a primarily fat-burning state that makes it easier to fast for long periods without hunger pangs by eating up to somewhere around 100 or 150g/day carbohydrate (assuming you eat a 2000-2500 Kcal/day diet) while providing enough glucose to the brain that your body is not forced to create excess Ketone bodies.
SoftwareMaven, I will suggest that one possible explanation is that our gut is filled with microbes (some good, some bad) and food is filled with microbes and, by weight, our poop is 50% microbes of some sort. So when you fast, you clean out bugs from your system, some of which are very not good for you. We seem to have lost this idea that we are organic, living creatures, part of a complex biome and seem to have this fantasy that we are merely ...chemically complex and in need of more building blocks. And life is just way, way more complicated than that. It is much closer to an on-going, multi-front battle. And when you never fast, you never take a break from that battle. It just keeps on going.
The more interesting part of this to my eyes was the material difference between 24 hour and 72 hour fasting in human chemotherapy patients, in that the former didn't do anything to the measure of immune cell populations and the latter did. Intermittent fasting is nowhere near as well studied as calorie restriction at this point in time, so it is interesting to see these mechanisms emerge.
Now this is chemotherapy immune suppression, not aging immune dysregulation. I'll be mildly surprised to see the exact same result in people with age-damaged immune systems, as the character of the damage is very different. The animal results for aging rather than chemotherapy here are intriguing but that's all. There's still a lot of work to be done to arrive at the level of comfort with this effect that exists for other aspects of calorie restriction or intermittent fasting.
But given that (a) obtaining human data on fasting and immune cell population in old people is a comparatively low cost study to put together, and (b) the group involved here seems to have a good flow of funding to study intermittent fasting in a broader context, I'd expect to see that data emerge at some point in the next few years.
> The more interesting part of this to my eyes was the material difference between 24 hour and 72 hour fasting in human chemotherapy patients, in that the former didn't do anything to the measure of immune cell populations and the latter did.
If you do zero-calorie fasting, there are some important changes around or after day 3. Hunger disappears. Metabolism is low, muscles are relaxed. The mind tends to more easily stay focused on a single topic. There's a sense of clarity and ease, and an odd kind of energy. It's quite a contrast with the increasingly frantic frustration prior to this time.
This is all from a subjective standpoint, of course, but it's well correlated by most people who have done it. It seems quite obvious that there are major changes around day 3. I'd love to see more data from studies.
Not having read the article, I wonder if this might be a common response in mammals -- if you're too sick to eat for two whole days, immune system "assumes"[1] it's missed something, and tries desperately to get you back to healthy enough to forage/hunt...?
[ed: well, that's entirely wrong, based on the article -- it's the body killing off as much dead weight as possible in order to hang on a bit longer -- then healing back up when food is avaliable. Oh, well :-) ]
[1] By which I mean there is some complex time-delayed protein-signal-avalanche that is somehow tied to long periods without nutrition...
My humble summary based on superficial reading of the paper:
* Prolonged fasting = Eating NOTHING for 48-120 hr.
* BENEFICIAL effect started on cycle 4 (day 39).
* 1 Cycle = 2-4d fasting&chemo; 8-10d recovery.
* Prolonged fasting enhances cellular resistance to
toxins in mice and humans.
* Glycogen depletion required => switch to fat/ketone
bodies-based catabolism (!!!).
* They have no idea, what the effects on blood are
in detail.
* At the beginning WhiteBloodCell count went down.
* After 6 cycles things stabilized.
One of the things I've been up to the last couple years is reducing the divergence between my life and the conditions I probably evolved for. E.g., much less processed food, reduced use of artificial light that diverges from the normal day/night cycle, more frequent modest physical exercise, very low sugar consumption, way less alcohol and caffeine. To me it feels a lot like when I'm debugging a system and am trying to get back to a baseline by eliminating complicating factors.
Lately I've been wondering about fasting in that context. Not eating occasionally was presumably pretty normal for our ancestors. Have other self-hackers here experimented with this?
I don't know that the biological benefits of fasting are associated directly with cultural fasting patterns in our ancestry.
I suspect they're more linked with our ancestral hunter-gatherer traits. It seems logical that early humans would go periods of time without eating while hunting, then consume a large amount of protein and fat in a short period of time.
Religious and cultural fasting, however, would likely have not occurred until the development of language which is estimated at 20k-50k years ago. That's not a particularly long time on an evolutionary scale.
It doesn't need to be the tradition that shaped our biology. It could be our biology that shaped the tradition. Assuming we already have some benefit to fasting, a group who make a tradition of fasting are more likely to survive than a group who does not. Thus the fasting meme takes over as the people who believe in it take over.
I agree that we're probably adapted, in our biology, to re-occurring intervals of food scarcity. I would not be surprised at all if it turned out that our bodies actually function better on that sort of regime (eat at will for a while, then forego all caloric intake for a brief period).
I wonder if this was noticed at the dawn of civilization, and then got codified into religion and so on.
From an evolutionary standpoint periods of famine were certainly a selective pressure for our ancestors. It could make sense that prolonged periods of no-food are not only something our bodies have adapted to survive, but have adapted to thrive upon as part of their natural cycle.
Sorry for being nit-picky. It is not that we evolved to thrive during periods of famine. It is that we did not evolve under conditions where resources were plentiful. That is why so many people die from heart conditions brought on by excessive eating. The machinery in our body is simply insufficient to deal with the excess cholesterol.
It could make sense that prolonged periods of no-food are not only something our bodies have adapted to survive, but have adapted to thrive upon as part of their natural cycle.
How do you make the jump from "Most able to survive famine." to "Thrive on famine."? It doesn't seem obvious to me that we would automatically evolve to the latter result over the former.
Let's look at what the submitted article, which is a press release from a university, says. "In both mice and a Phase 1 human clinical trial, long periods of not eating significantly lowered white blood cell counts. In mice, fasting cycles then 'flipped a regenerative switch,' changing the signaling pathways for hematopoietic stem cells, which are responsible for the generation of blood and immune systems, the research showed."
What's good about this line of research is that it is trying to show whether or not an observation found in a model animal will also be found in human patients. As preliminary research, this will have to be replicated by other researchers before we can rely on this finding (NOT extended fully to human patients in the current study) to guide treatment of human patients.
This is good news that people are investigating this issue. Once there has been a thorough review article on this issue published in a different journal by a different author, summing up several well designed studies, then we will really have something to talk about here on Hacker News.
I should comment on some of the other comments here. One very tricky problem in studies of human nutrition is that there isn't a good model organism for nutrition and its effect on human health. The study reported here, just like most medical intervention studies, begins in a mouse model. Mice are well understood organisms and their similarities to and differences from human beings for many medical treatments are well understood. Mice are not a particularly good model for nutrition studies, however, because mice are rodents (part of a clade of obligate herbivores) while human beings are primates (part of a clade of facultative omnivores). Moreover, human beings, the current species Homo sapiens, have evolved with co-evolution of the gut in the environment of the cultural practice of cooking food.[1] Cooking is a human cultural universal. No other animal lineage has evolved in a similar environment, so no animal provides a fully suitable model for studies of human nutritional interventions.
Human nutrition studies are HARD, because they require minute-by-minute monitoring of the subjects and exact measurements of food intake to gather meaningful experimental data. (I recall a TV news report from the 1970s about a human nutrition study in which the study volunteers, who of course were paid for this, lived confined inside a lab in which lab technicians weighed all their food to the nearest gram and controlled everything they could eat for the duration of the experiment. Alas, I've never heard of results of that study, perhaps because the sample size, with such an expensive procedure, was too small to generate meaningful data.) Yes, let's see what nutritional interventions do what for human beings, but let's be careful not to jump to conclusions too soon, because careful data gathering on this topic is especially difficult, and anecdotes crowd out data in most popular discussion of this topic.
One also has to look at the surrounding studies for context and plausibility, not just this one in isolation. For example, I think you are overcautious in your comments on nutrition data in humans for calorie restriction and fasting - there is in fact quite a large amount of support for both benefits and safety in humans, both in the context of augmenting chemotherapy and as a general health practice. There is further an enormous weight of evidence in various mammal species for the benefits of calorie restriction and fasting.
In the case of this particular item, referring specifically to alterations to the white blood cell counts and lineages, the human data only goes so far as chemotherapy patients, and not very many of them. Talking about age-altered immune systems is premature. It would not be a surprising result if validated by other researchers, as calorie restriction and fasting are already known to beneficially influence immune function over the long term, but the details here should be taken as merely interesting until someone else runs larger studies to obtain more data.
(I recall a TV news report from the 1970s about a human nutrition study in which the study volunteers, who of course were paid for this, lived confined inside a lab in which lab technicians weighed all their food to the nearest gram and controlled everything they could eat for the duration of the experiment. Alas, I've never heard of results of that study, perhaps because the sample size, with such an expensive procedure, was too small to generate meaningful data.)
I am curious what your thoughts are for a reasonable means to gather data here and draw conclusions. Something practical and do-able. Is there anything that you would think was any good?
Is calorie constriction considered nutrition? Of course animals will have evolved different food requirements, but it seems like the basic mechanism of responding to a lack of calories should be the same.
As someone who doesn't know very much about the immune system - I wonder if this 'resetting' property could be used to treat allergies or other minor autoimmune problems.
Also, I'd appreciate a medium-level overview of the immune system, if anyone has a good link.
Anecdotal evidence, for sure (and IANAD/IANYD), but I've found that fasting eliminates my food sensitivities (both water fasts and apple fasts, where you just eat an apple or two a day, have done the trick for me). They eventually come back after a month or so (no science behind it, but it feels like a slow buildup of whatever was initially bothering me), at which point, I can fast again with similar positive result. I find it's safer/healthier than living on Prilosec...
This book[1] is the best resource for a "medium-level" overview I've come across. Once you get beyond that, you're entering textbook and then paper territory.
Pathology resident here, starting a flow cytology rotation next month (diagnosing disease by studying live immune cells with lasers and antibodies). My best advice is to realize this stuff is really complicated. Start by synthesizing your own hematopoietic cell lineage diagram from existing versions (google image search for them) and use that as your foundation when reading texts.
I'm not familiar with what is out there as far as materials, but I would speculate that beyond that to get an overview you would end up looking at a medical textbook (with shorter treatments being more specific).
Fasting has always been a tradition in many religious groups. It would interesting to study groups that fasted regularly to see what affect it had on longevity.
Calorie restricted diets have been extensively studied. Radically reducing your food intake is about the only known way to seriously extend lifespan. The trend holds true for virtually every multi-cellular organism ever tested under laboratory conditions.
AS a religious practice I would fast one day a week from sunset to sunset.
(Ancient day was from sunset to sunset) But mainly that was an easy thing to do. I only drank water. I would also do some three or four day and I am mad at myself for not practicing fasting more often. I could think so much better and was a great form of self-discipline.
Most modern Christians have a wacky idea of fasting. Most do not go water only. Several will drink liquid juices and other liquid foods. No idea why???? Or there is the weird modern invention called the "Daniel Fast" which equals eating Kosher in the Bible but in practice it is eating like a vegetarian for a few days or weeks. No idea how this happened.
I'll recommend fasting with fellow Muslim friends and co-workers for a day during Ramadan. it is very rewarding and revealing about our daily routines and eating habits. I enjoy high productivity during Ramadan, plus it is healthy.
You know I've had a hunch for a while there must be something to these "detox" diets where you just eat a bunch of carrots or whatever. I think it's increasingly clear collateral fasting is the answer. The gimmick is "it's the carrots", the reality is you're inducing an extended fasting state which has all kinds of beneficial impacts on the body.
The science is increasingly clear that humans should be putting their body in a fasting state far more often and for far longer than we in the decadent west do.
Wonder if you can approximate the effect with regular blood donations? It's my understanding that regular blood donations are a good idea for males because it helps clear out old red blood cells with iron buildups. Clearing out old white blood cells could be yet another motivator.
Certain body systems only activate certain processes when the body isn't processing food. Firstly, the gut is an immune organ. Think of it this way: this inside of the digestive system is technically outside the body. It is a continuous tube mouth to anus, and functions as an interface between the outside world and systemic circulation - both blood and lymphatic. The gut has GALT - Gut-Associated Lymphoid Tissue [1]. Lymphatic tissue is an immune system organ and a waste disposal system [2].
It's important to note that all (most) fats are first absorbed by the GALT (specically Lacteals [3]), where it then takes some time to enter blood circulation - the Thorasic Duct [4] (largest lymph vessel) drains in to the Subclavian Vein [5] - so any fat soluble toxins (as in, fat soluble non-nutrients and / or outright toxic molecules) are absorbed by the GALT and removed by white blood cells. Only when this system isn't being stressed by our regular (and typically poor) food intake can the immune system attend to it's ordinary tasks of dealing with regular cellular waste products.
Aditionally, Caffeine consumption reduces immune activity [6]. Alcohol (ethanol) is a Type 1 / Group A carcinogen [7] - why doesn't alcohol packaging state this in the same way cigarette packaging does (in Australia, at least).
Full Disclosure: this is my field of expertise, I hold an Advanced Diploma in Clinical Nutrition from an Australian Nationally Accredit Training organisation. I have been actively studying this field for over ten years.
Aside from the non-sense of miracles etc., it has been a tradition in yogis in India to fast regularly. Maybe the positive effects were observed/known even in those older times.
The article seems pretty obvious. If you don't eat food, your body will eat itself. It would make sense for it to eat the worst cells first. Then when you add new food into the system it can replace those cells.
Perhaps fasting was more common in the past, so it was a reliable trigger for this behavior, and our bodies did not need to develop their own automatic trigger. Why waste resources rebuilding things, after all?
[+] [-] SoftwareMaven|11 years ago|reply
On a personal note, I found fasting became much easier after I changed my diet to be ketogenic. With a metabolism primed for burning fat for energy and not subject to a blood sugar roller coaster, going a couple days without food is more of a mental challenge than physical hunger.
1. We've acted like nutrition can give the same cut and dry answers that physics has, and the health of our population shows how well that has worked. Worse, nutrition seems to be driven by egos and media in a way that is nothing short of frightening.
[+] [-] DenisM|11 years ago|reply
The average lifespan has gone up considerably in recent decades, and people remain active longer than ever, i.e. people are gaining productive years, not just end-of-life years.
In other words, "it" worked fairly well.
[+] [-] Florin_Andrei|11 years ago|reply
This is a cultural rift between Western Europe and everyone else. I grew up in Eastern Europe (now I live in the US), and fasting was not an extraordinary concept in that culture, by any means. But I keep noticing how controversial it is in the West.
I could probably speculate on the influence of material wealth on culture, and so on, but there's probably not much of a point here.
> I found fasting became much easier after I changed my diet to be ketogenic.
You don't need to go that far. Fasting is easy when you don't do any kind of alimentary excess in general.
I think the whole keto concept is just the pendulum swinging all the way to the other side. I guess it will settle in the middle at some point. Eat a bit of everything, nothing in excess, make sure to not miss the greens and the fruits, etc. Self-control and self-limiting are things that we all need to re-train ourselves for - and not just when it comes to food.
---
Anyway, I'm far more interested in studies regarding the effects of fasting on the brain. Traditionally, it was used in a spiritual context, by people who, for lack of a better term, were consciousness hackers. Fasting seemed to enable that process, whatever the mechanism.
I'm also very curious about the effects of fasting, if any, on neurodegenerative diseases.
[+] [-] thenmar|11 years ago|reply
[+] [-] bane|11 years ago|reply
Scientific models haven't been all that great either, but science hopefully will eventually self correct as nutritional models become more sophisticated. If there is light at the end of the tunnel it will be because of the eventual understanding that the scientific method provides, not reverting back to traditional models.
Traditional models don't self correct and there are plenty of instances of people consuming outright poisons under such systems or people following traditional nutrition models finding themselves surrounded by an abundance of previously rare foods that the modern food supply system easily provides, and practically gorging themselves on it to negative health results.
[+] [-] Houshalter|11 years ago|reply
[+] [-] rdmcfee|11 years ago|reply
I typically eat ~12 meals per week, 2000 kcal per meal.
In addition, the consistent mental acuity achieved in ketosis is fantastic.
[+] [-] raverbashing|11 years ago|reply
Also, science "doesn't know what it doesn't know yet", so we may be missing something that was inconspicuously removed, or suffering from something that was apparently safe
One of the interesting things is knowledge that existed and that was rediscovered by science, like http://en.wikipedia.org/wiki/Nixtamalization
[+] [-] TylerJay|11 years ago|reply
Ketosis is a state where you eat so little carbohydrate, that your body is forced to create "ketone bodies" to fuel the brain. This typically happens at <50g/day carbohydrate.
Most anecdotal evidence (and my own experiences) show that you can get your body into a primarily fat-burning state that makes it easier to fast for long periods without hunger pangs by eating up to somewhere around 100 or 150g/day carbohydrate (assuming you eat a 2000-2500 Kcal/day diet) while providing enough glucose to the brain that your body is not forced to create excess Ketone bodies.
[+] [-] dzhiurgis|11 years ago|reply
[+] [-] Mz|11 years ago|reply
my 2 cents, fwiw.
[+] [-] exratione|11 years ago|reply
http://dx.doi.org/10.1016/j.stem.2014.04.014
The more interesting part of this to my eyes was the material difference between 24 hour and 72 hour fasting in human chemotherapy patients, in that the former didn't do anything to the measure of immune cell populations and the latter did. Intermittent fasting is nowhere near as well studied as calorie restriction at this point in time, so it is interesting to see these mechanisms emerge.
Now this is chemotherapy immune suppression, not aging immune dysregulation. I'll be mildly surprised to see the exact same result in people with age-damaged immune systems, as the character of the damage is very different. The animal results for aging rather than chemotherapy here are intriguing but that's all. There's still a lot of work to be done to arrive at the level of comfort with this effect that exists for other aspects of calorie restriction or intermittent fasting.
But given that (a) obtaining human data on fasting and immune cell population in old people is a comparatively low cost study to put together, and (b) the group involved here seems to have a good flow of funding to study intermittent fasting in a broader context, I'd expect to see that data emerge at some point in the next few years.
[+] [-] Florin_Andrei|11 years ago|reply
If you do zero-calorie fasting, there are some important changes around or after day 3. Hunger disappears. Metabolism is low, muscles are relaxed. The mind tends to more easily stay focused on a single topic. There's a sense of clarity and ease, and an odd kind of energy. It's quite a contrast with the increasingly frantic frustration prior to this time.
This is all from a subjective standpoint, of course, but it's well correlated by most people who have done it. It seems quite obvious that there are major changes around day 3. I'd love to see more data from studies.
[+] [-] CreRecombinase|11 years ago|reply
http://www.cell.com/cell-stem-cell/pdf/S1934-5909(14)00151-9...
[+] [-] e12e|11 years ago|reply
[ed: well, that's entirely wrong, based on the article -- it's the body killing off as much dead weight as possible in order to hang on a bit longer -- then healing back up when food is avaliable. Oh, well :-) ]
[1] By which I mean there is some complex time-delayed protein-signal-avalanche that is somehow tied to long periods without nutrition...
[+] [-] rawland|11 years ago|reply
Interesting figures from the paper: http://www.cell.com/cms/attachment/2014950454/2036225024/gr1...
[+] [-] wpietri|11 years ago|reply
Lately I've been wondering about fasting in that context. Not eating occasionally was presumably pretty normal for our ancestors. Have other self-hackers here experimented with this?
[+] [-] niels_olson|11 years ago|reply
http://nielsolson.us/blog/2012/08/28/my-diet/
[+] [-] consideranon|11 years ago|reply
[0] http://www.marksdailyapple.com/health-benefits-of-intermitte... [1] http://www.leangains.com/2010/04/leangains-guide.html
[+] [-] rdmcfee|11 years ago|reply
I suspect they're more linked with our ancestral hunter-gatherer traits. It seems logical that early humans would go periods of time without eating while hunting, then consume a large amount of protein and fat in a short period of time.
Religious and cultural fasting, however, would likely have not occurred until the development of language which is estimated at 20k-50k years ago. That's not a particularly long time on an evolutionary scale.
[+] [-] tiglionabbit|11 years ago|reply
[+] [-] Florin_Andrei|11 years ago|reply
I wonder if this was noticed at the dawn of civilization, and then got codified into religion and so on.
[+] [-] ihnorton|11 years ago|reply
http://www.ncbi.nlm.nih.gov/pubmed/20534972
http://www.nature.com/nature/journal/v468/n7327/full/nature0...
[+] [-] awolf|11 years ago|reply
[+] [-] jostmey|11 years ago|reply
[+] [-] Goronmon|11 years ago|reply
How do you make the jump from "Most able to survive famine." to "Thrive on famine."? It doesn't seem obvious to me that we would automatically evolve to the latter result over the former.
[+] [-] tokenadult|11 years ago|reply
What's good about this line of research is that it is trying to show whether or not an observation found in a model animal will also be found in human patients. As preliminary research, this will have to be replicated by other researchers before we can rely on this finding (NOT extended fully to human patients in the current study) to guide treatment of human patients.
This is good news that people are investigating this issue. Once there has been a thorough review article on this issue published in a different journal by a different author, summing up several well designed studies, then we will really have something to talk about here on Hacker News.
I should comment on some of the other comments here. One very tricky problem in studies of human nutrition is that there isn't a good model organism for nutrition and its effect on human health. The study reported here, just like most medical intervention studies, begins in a mouse model. Mice are well understood organisms and their similarities to and differences from human beings for many medical treatments are well understood. Mice are not a particularly good model for nutrition studies, however, because mice are rodents (part of a clade of obligate herbivores) while human beings are primates (part of a clade of facultative omnivores). Moreover, human beings, the current species Homo sapiens, have evolved with co-evolution of the gut in the environment of the cultural practice of cooking food.[1] Cooking is a human cultural universal. No other animal lineage has evolved in a similar environment, so no animal provides a fully suitable model for studies of human nutritional interventions.
Human nutrition studies are HARD, because they require minute-by-minute monitoring of the subjects and exact measurements of food intake to gather meaningful experimental data. (I recall a TV news report from the 1970s about a human nutrition study in which the study volunteers, who of course were paid for this, lived confined inside a lab in which lab technicians weighed all their food to the nearest gram and controlled everything they could eat for the duration of the experiment. Alas, I've never heard of results of that study, perhaps because the sample size, with such an expensive procedure, was too small to generate meaningful data.) Yes, let's see what nutritional interventions do what for human beings, but let's be careful not to jump to conclusions too soon, because careful data gathering on this topic is especially difficult, and anecdotes crowd out data in most popular discussion of this topic.
[1] http://www.scientificamerican.com/article/cooking-up-bigger-...
http://www.popsci.com/science/article/2012-10/eating-cooked-...
http://www.smithsonianmag.com/science-nature/why-fire-makes-...
[+] [-] exratione|11 years ago|reply
In the case of this particular item, referring specifically to alterations to the white blood cell counts and lineages, the human data only goes so far as chemotherapy patients, and not very many of them. Talking about age-altered immune systems is premature. It would not be a surprising result if validated by other researchers, as calorie restriction and fasting are already known to beneficially influence immune function over the long term, but the details here should be taken as merely interesting until someone else runs larger studies to obtain more data.
[+] [-] Mz|11 years ago|reply
I am curious what your thoughts are for a reasonable means to gather data here and draw conclusions. Something practical and do-able. Is there anything that you would think was any good?
[+] [-] Houshalter|11 years ago|reply
[+] [-] Yen|11 years ago|reply
Also, I'd appreciate a medium-level overview of the immune system, if anyone has a good link.
[+] [-] jen_h|11 years ago|reply
[+] [-] ihodes|11 years ago|reply
[1]: http://www.amazon.com/Immune-System-Includes-Desktop-Edition...
[+] [-] niels_olson|11 years ago|reply
[+] [-] brm|11 years ago|reply
[+] [-] maxerickson|11 years ago|reply
http://en.wikipedia.org/wiki/Immune_system
I'm not familiar with what is out there as far as materials, but I would speculate that beyond that to get an overview you would end up looking at a medical textbook (with shorter treatments being more specific).
[+] [-] coldcode|11 years ago|reply
[+] [-] jostmey|11 years ago|reply
[+] [-] baldfat|11 years ago|reply
Most modern Christians have a wacky idea of fasting. Most do not go water only. Several will drink liquid juices and other liquid foods. No idea why???? Or there is the weird modern invention called the "Daniel Fast" which equals eating Kosher in the Bible but in practice it is eating like a vegetarian for a few days or weeks. No idea how this happened.
[+] [-] mgulaid|11 years ago|reply
[+] [-] Evgeny|11 years ago|reply
http://www.cell.com/cell-stem-cell/pdf/S1934-5909(14)00151-9...
[+] [-] themgt|11 years ago|reply
The science is increasingly clear that humans should be putting their body in a fasting state far more often and for far longer than we in the decadent west do.
[+] [-] corysama|11 years ago|reply
[+] [-] sp332|11 years ago|reply
Edit: a few months, not weeks. But cells dying faster seems to be related to diseases, not health. https://en.wikipedia.org/wiki/Red_blood_cell#Life_cycle
[+] [-] achille2|11 years ago|reply
The article is a bit vague: periods of no food for two to four days at a time over the course of six months
[+] [-] kumarski|11 years ago|reply
http://www.quora.com/Clinical-Trials/What-are-examples-of-dr...
[+] [-] TheSpiceIsLife|11 years ago|reply
It's important to note that all (most) fats are first absorbed by the GALT (specically Lacteals [3]), where it then takes some time to enter blood circulation - the Thorasic Duct [4] (largest lymph vessel) drains in to the Subclavian Vein [5] - so any fat soluble toxins (as in, fat soluble non-nutrients and / or outright toxic molecules) are absorbed by the GALT and removed by white blood cells. Only when this system isn't being stressed by our regular (and typically poor) food intake can the immune system attend to it's ordinary tasks of dealing with regular cellular waste products.
Aditionally, Caffeine consumption reduces immune activity [6]. Alcohol (ethanol) is a Type 1 / Group A carcinogen [7] - why doesn't alcohol packaging state this in the same way cigarette packaging does (in Australia, at least).
1. http://en.wikipedia.org/wiki/Gut-associated_lymphoid_tissue
2. http://en.wikipedia.org/wiki/Lymphatic_system
3. http://en.wikipedia.org/wiki/Lacteal
4. http://en.wikipedia.org/wiki/Thoracic_duct
5. http://en.wikipedia.org/wiki/Subclavian_vein
6. http://www.sciencedirect.com/science/article/pii/S1567576904...
7. http://www.cancer.org/cancer/cancercauses/othercarcinogens/g...
Full Disclosure: this is my field of expertise, I hold an Advanced Diploma in Clinical Nutrition from an Australian Nationally Accredit Training organisation. I have been actively studying this field for over ten years.
Edit: link to my blog http://thecurrentstandard.wordpress.com
[+] [-] noisy_boy|11 years ago|reply
[+] [-] mc_hammer|11 years ago|reply
bath houses and sauna (sweat lodges also), fasting, fish and potatoe diets, beer and wine consumption (maybe was not considered good, but was common)
all seem to have lost ground.
i could also argue that eating sushi or seaweed is on the list, also, peace pipe (!), and 2-sleep days (sleep+"second sleep").
im currently leaning towards these being better for us that 9-5 coffee strung out + staring at a lcd all day... by a lot
[+] [-] tiglionabbit|11 years ago|reply
Perhaps fasting was more common in the past, so it was a reliable trigger for this behavior, and our bodies did not need to develop their own automatic trigger. Why waste resources rebuilding things, after all?