
Fasting triggers stem cell regeneration of damaged, old immune system (2014) - prostoalex
http://www.eurekalert.org/pub_releases/2014-06/uosc-fts060214.php
======
reasonattlm
Better publicity materials:

[http://www.eurekalert.org/pub_releases/2014-06/uosc-
fts06021...](http://www.eurekalert.org/pub_releases/2014-06/uosc-
fts060214.php)

The paper:

[http://dx.doi.org/10.1016/j.stem.2014.04.014](http://dx.doi.org/10.1016/j.stem.2014.04.014)

Really it's just not worth even reading whatever the popular press has to say
about a particular strand of research, especially when lines like "regenerate
the entire immune system" are thrown around. No, no, no. Not what is
happening: read the paper or even just the publicity materials. It is a very
specific mechanism involving specific cell populations.

This is of interest to me primarily because it draws a comparatively sharp
line in the sand between the occurrence of a beneficial immune system behavior
that happens after three days of fasting but not prior to that point. There
are not too many other items I can think of in connection with fasting or
calorie restriction that have this discrete on/off behavior. It would be
interesting to repeat this in healthy volunteers rather than cancer patients.

~~~
con-templative
> Really it's just not worth even reading whatever the popular press has to
> say about a particular strand of research, especially when lines like
> "regenerate the entire immune system" are thrown around.

To look at it from the opposite perspective, here's a helpful guide for
scientists on how to get a health study into the UK news:
[http://www.nhs.uk/news/2014/12December/Pages/your-guide-
to-h...](http://www.nhs.uk/news/2014/12December/Pages/your-guide-to-hitting-
the-headlines.aspx)

~~~
DanBC
I love the NHS (UK National Health Service) information "Behind the Headlines"
site that your link comes from.

[http://www.nhs.uk/news/Pages/NewsIndex.aspx](http://www.nhs.uk/news/Pages/NewsIndex.aspx)

~~~
con-templative
Amen. I imagine they'll have a post on the Telegraph article in a week or so.

------
atoponce
I recognize this as completely empirical evidence, so take it as that.

I am a Mormon. As part of our religious observance, we fast for 2 meals on the
first Sunday of every month. Also, I have fasted for the entire duration of
the Muslim month of Ramadan twice now.

For Mormons, food and drink is abstained starting Saturday night after dinner
until Sunday night's dinner. By the time dinner rolls around Sunday night, I
am pretty weak. However, I have noticed that when I fast that Sunday, the
following week, my system seems to clean itself out. I feel more alert, and
energy seems to peak for a prolonged duration that first week.

While participating in Ramadan, food and drink is abstained from dawn to
sunset for each day during the month. This usually means packing in the
necessary proteins and carbohydrates for slow breakdown in the morning, and a
filler at night. Both times, I shed about 10-15 pounds.

Ramadan was much more difficult for me to participate in, because I need to
remain alert and active while at work. I can maintain that needed level until
early in the afternoon, when I start to slow down. By the time my shift is
over, I'm really not very productive. However, right about the time I am
getting off of my shift, I notice that my hunger pains disappear, even though
I'm still weak.

While I can't say I notice the increased energy or alertness at the end of the
Ramadan, shedding the weight was a positive bonus, although it was not
intended.

In both cases, Mormon fasting and participating in Ramadan, I can say that I
have noticed personal health benefits, whether it is increased energy, or
losing weight. Others I have talked to have noticed the same thing, both
Mormons and Muslims alike.

So, it doesn't surprise me that there will be immune system benefits as well.

~~~
mb_72
I have Crohn's disease, have therefore been exposed to numerous doubtful
stories about 'boosting the immune' system. With my illness, a 'boost' would
actually make me sicker, whereas I find that fasting for a couple of days
results in improvement of symptoms for me. Why? Obviously because my digestive
system becomes empty, and there is less irritation of damaged intestinal
lining. Going by this study, an increased production of white blood cells
should make me sicker. My anecdotal evidence does not support their findings.

Long story short - if their claims are true they will be able to be reproduced
by other researchers. Until then, colour me sceptical.

~~~
rjurney
For your Crohn's, fasting would be similar to total bowel rest, wouldn't it?
i.e. it would help the bowel heal.

~~~
mb_72
Yes, I believe that is what happens. On the other hand, my symptoms often seem
to improve if I eat pizza for each meal for 24hrs (order one night, consume
left overs for the next day). :)

Crohn's is one illness that attracts more than it's fair share of woo and
'special diets' and so on. As a result I've become fairly sceptical of any
one-off scientific papers that make certain claims, whether they are related
to auto-immune diseases or not.

~~~
shanusmagnus
Your skepticism is probably good, but fasting (and its semi-related brother,
caloric restriction) has been the subject of scientific investigation for a
long time, so 'one-off' hardly captures the essence of it.

------
PakG1
I fasted once for three days in university. Only water. Bumped into a friend
who raved about it and so I tried it out. It was a faith thing.

First day was not bad.

Second day was horrible. That day just happened to be the day when all these
university student associations decided to put on a whole bunch of events that
had food. The First Nations Student Association served roasted corn, salmon,
and bannock. Another club had pizza. An info session for overseas exchange
studies had sushi, cookies, veg and dip, and so on. On it went. It sucked. My
friend had allowed himself one cup of fruit juice during his three days, so I
allowed myself one cup at the exchange info session. Dang, I needed a lot of
willpower that day.

Third day was fine, it felt like I was actually starting to adjust to lack of
food. But knew eventually I had to eat so fourth day I ate.

I try it every now and then. Honestly, if I can get over the hump of those big
hunger pangs, it gets easier. Part of it may be because I eat too much in
general though. Hehe.

~~~
schrodinger
I was doing two day fasts ever other week or so for a while. The first time,
it was really hard - I felt sick to my stomach, weak, and almost gave up.
After that time though, once I realized that no it's not going to kill me, got
much easier and I actually started to enjoy the relaxation it brought.

------
justinpaulson
Thought I would weigh in as I have a personal interest and history with
fasting.

I once fasted for 25 days on nothing but water. I biked to class and work
daily during the fast. After a couple days, hunger cravings disappeared. After
two weeks I began to gain a mental clarity that I had not encountered before.
I would get a head rush when I stood up too quickly after about 15'r days, but
this was remedied by taking a deep breath beforehand. You begin to see and
think of things differently when you find that you have given up an activity
like eating that is so fundamental to human existence. I lost about 30 pounds
(196-166) but almost immediately gained 15 back when I started eating again. I
still remember how amazing a strawberry tasted the first time I ate after 25
days. I found a new appreciation for all types of foods I had never enjoyed
before Infasted. It was a monumental experience in my life.

There are some commenters claiming different things about fasting, but the
body is a miraculous thing and it can go quite some time without food. I plan
to complete a 40 day fast along the lines of the Pythagoreans, Buddha, Jesus,
and the ancient Egyptian Schools.

I do not, however, recommend this for everyone. An average person should have
no problems with a prolonged fast, but there are no guarantees that you do not
have some dormant medical issue. I went about my fast rather naively with no
medical supervision, and though I had no negative consequences, I can not
recommend my actions to others for obvious reasons. I am merely sharing my
personal experience.

In a more relevant note to the article, I have found that fasting always makes
me recover from an illness more quickly. If I have a cold or any other trivial
illness I always fast and recover fairly quickly, again N=1. But I did come to
the conclusions of this idea after extensive research into the benefits of
fasting.

~~~
shanusmagnus
The mental clarity you mention is interesting. Did you by any chance do stuff
during that stretch that would give a more objective mental performance --
meaning, was there a quantitative way for you to evaluate your 'mental
clarity'?

I ask because I've water-fasted for two days on several occasions, and I've
always broken because the mental handicap was just too much, and I've had work
to do.[1] In particular, I've found that writing code and writing research
papers is almost impossible on day 2.

However, I've wondered if either a) pushing through it, or b) keto-adapting
beforehand might prevent the mental slowness. I know a superstar scientist who
claims that he thinks better in ketosis, so presumably the mechanism for
pushing through it would be to get to the point of keto-adaptation.

[1] Well, that's kind of a copout. I could always do it while on vacation or
something. So mental handicap + willpower.

~~~
justinpaulson
I would say that day 2 is probably the hardest day. Day 3 was when I really
started to feel almost normal, I lost cravings for food I mean. The craving
and mental occupation of hunger is really distracting the first couple of
days. After that you can focus more on your normal tasks without the constant
nagging reminder that you are fasting. In fact, after about 12 days someone
offered me a cookie at work and I almost took it and started eating it because
it just completely skipped my mind that I had been fasting. I finally caught
myself right before I started to eat it, but the hunger was so far gone from
me that I wasn't mouth-wateringly rabid about eating a cookie, it was just
like "sure, I'll take one" without a thought about it. So, I would probably
say pushing through to at least day 3 or 4 would be worthwhile. If you steal
feel handicapped after those days then it probably isn't for you.

I wish I had done some sort of quantitative test to see if this was
beneficial. I was taking 3 summer classes and working 20-30 hours at a pizza
place (yes, hand making pizza all day at Shakespeare's Pizza in Columbia, MO
while I was fasting.) And I did well in the classes, but I wouldn't say they
were the most challenging classes as far as math and science, it was two
philosophy classes and one theoretical physics writing class that was a lot
more theoretical than practical application and calculation. Perhaps next time
I will take some sort of mental performance tests at each week interval and
see if there is marked improvement or detriment.

~~~
shanusmagnus
Thanks for the feedback. Your classwork under fast is inspiring, since it
sounds like it included some fairly diverse cognitive skills. In my case
trying to write a paper was a really emphatic illustration that something
weird was going on, since I could do other, simpler tasks without really
noticing a difference. But creative, integrative work that required planning
and holding multiple things in memory at once was like running into a tree.

The pizzeria thing, on the other hand, doesn't really surprise me. I worked in
a pizzeria once, and my experience there (and from talking to other friends in
fast food) was that the more time you spend in food prep, the less hungry you
are. There might be eating out of impulse, but the hunger triggers seem to go
away pretty quick.

I'd encourage you in your final sentiment, though: quantitative performance
info on fasting would be really useful, and doesn't seem to exist in the
literature. If you ever want to talk about it please PM me.

------
bicknergseng
>>But I think the most sensible way forward would be to synthesize this effect
with drugs.

I'm no naturopath, but something about this attitude really bugs me. I know in
context he was cautioning against jumping to conclusions, but if there was a
safe, low barrier to entry, non-drug way of achieving an effect, why would you
encourage people to take a drug instead?

~~~
ovi256
Fasting for three days is not a safe, low barrier to entry, way. A healthy
person with no critical commitments or delicate work can do it safely, but
lots of people would not. Note that one side effect observed during the
protocol was fainting.

~~~
crystaln
Is there any evidence that fasting for 3 days is not safe or is this just an
assumption? As I understand it is perfectly safe for all but the most fragile
people.

~~~
toomuchtodo
As long as you're in good health and stay hydrated, you can safely fast for
almost 30 days.

[http://www.ncbi.nlm.nih.gov/pubmed/25552155](http://www.ncbi.nlm.nih.gov/pubmed/25552155)

"Conclusion: Ramadan fasting is associated with transiently impaired insulin
sensitivity, compensated for by an increased p3-cell function. However, the
pattern of insulin resistance-mediating adipocytokines suggests a potentially
beneficial metabolic effect of Ramadan fasting."

[http://www.scientificamerican.com/article/how-long-can-a-
per...](http://www.scientificamerican.com/article/how-long-can-a-person-sur/)

"At the age of 74 and already slight of build, Mahatma Gandhi, the famous
nonviolent campaigner for India's independence, survived 21 days of total
starvation while only allowing himself sips of water. In a 1997 article in the
British Medical Journal, Michael Peel, senior medical examiner at the Medical
Foundation for the Care of Victims of Torture, cites well-documented studies
reporting survivals of other hunger strikers for 28, 36, 38 and 40 days."

[http://www.bbc.com/news/magazine-17095605](http://www.bbc.com/news/magazine-17095605)

"Experts believe it is possible for the human body to survive without food for
up to two months."

~~~
benwr
Ramadan fasting is only during daylight hours, and is not remotely like
foregoing food entirely for even 36 hours.

~~~
toomuchtodo
My understanding of nutrition regarding both intermittent and long-term (at
least 6-10 days) fasting is that as long as your body can properly regulate
insulin levels and you have fat reserves, you're not in danger of health
issues from it. That's exactly what fat reserves are for.

A paper on obese women fasting for 6 days:
[http://www.ncbi.nlm.nih.gov/pubmed/9330585](http://www.ncbi.nlm.nih.gov/pubmed/9330585)

Effect of long-term fasting of obese patients on pancreatic exocrine function,
gastrointestinal hormones and bicarbonate concentration in plasma (20 days):
[http://www.ncbi.nlm.nih.gov/pubmed/6207670](http://www.ncbi.nlm.nih.gov/pubmed/6207670)

------
fasting34
Fasted once for 4.5 days (5 nights) and and blood work done just before
breaking the fast.

The fast was purely water based, cold turkey (no gradual caloric reduction).

The first 2 days were a bit hard because I felt hungry, after that I felt no
hunger, slept really well, woke up well rested but with tingles in my feet and
felt very alert though also calm.

One night I woke up to pee (I drank a lot of water) and I still don't remember
what happened but I woke up with my head on the toilet bowl.

The blood work came up all messed up.

Glucose levels were extremely low. Sedimentation rate extremely high. Lots of
ketones in the urine.

Broke the fast with some fruit juice and had no problems.

I've also engaged in intermittent water fading for about 3 months. All went
fine.

Once spent almost 40 hours of total fasting (no water). Do not recommend it, I
felt seriously messed up.

------
fady
i fasted for 14 days on spirulina tablets and water as an office bet to prove
its effectiveness and still take it everyday. every now and then i do 3-5 day
fast to cleanse my body, but technically i'm still eating food. i have yet to
do any blood tests to prove its effectiveness besides my own experiments and
what i've read. i also don't recommend people doing a fast for 14 days...maybe
3-5 days at first.

after the first few days without eating normal/cooked food it became easier
per say, as cravings went down and your body goes into fast mode, even when
consuming raw spirulina. i found weekends to be tough as you tend to go out
more, and ads are everywhere for food.

also, after the second day you really start to shed water weight and your
caloric intake dips into the negatives, as spirulina has about 10 calories per
serving which is about 3g. i took an average about 30-60 tablets a day,
roughly 2/3g (4-6 tabs) per doze. you drink a lot of water (which you should
be doing anyway) m-f was easier for me as you're busy with work when compared
to the weekends.

it was asked, how will we know if i'm honest and actually don't eat? we
decided on the honor system and we did the math, loosely. in 14 days i should
lose about 14lbs, at 1 pound /day, so i did a weigh in before and after. on
the last day i weighed in and i did lose about a pound a day with a total of
14.6 lbs lost and i felt..good?/fine, lost weight, had new perspective at
starvation, and food itself. you still should eat more than spirulina, which i
did at 9pm that monday...green apples and raw chocolate bars were my choices
:)

spirulina (cyanobacteria) gives you insane amounts of energy and contains a
boat load of nutrients (rich in vitamin A (beta-carotene), B1, B2, B3, B6, E,
and K). it also converts sunlight to protein more efficiently than any other
living thing. it has the highest content of protein of any other food source
around roughly (65-71%). its ancient food, and one of the important foods of
the future. it along with other raw foods (fruits/veggies) IMHO is better for
you than any other human made sludge/supplements. you can't beat real food and
nature.

~~~
scrapcode
Can you share further reading material or studies behind spirulina?

~~~
keenerd
The wikipedia page on the topic appears reasonably good:
[http://en.wikipedia.org/wiki/Spirulina_(dietary_supplement)](http://en.wikipedia.org/wiki/Spirulina_\(dietary_supplement\))

However it can't be the only thing you eat. There were some studies about
using spirulina on a spacecraft (or sub) for both 100% of oxygen and food.
While it was feasible, it was pretty energy intensive and would tend to kill
you after a few months. Something about more protein in the blood than your
kidneys could filter? Will try to find a link.

~~~
fady
i agree and mention that. i just did not want to fast without protein and
other essential vitamins hence the idea to try it. i should have documented it
more with vids, etc.

maybe it was the sodium?

~~~
keenerd
I'm talking about the side effects of eating 2000 kcals of it a day. The
quantities you were doing (150 kcals?) probably don't have those issues.

~~~
fady
yeah 150-300 kcals max.

edit: wanted to add/clarify that some days i only took half of what i
planned..was not hungry. my friend said i need to eat 3000 kcals of it..i said
no, as i'm just going to get an athletes dose of it. the bet was to show you
could function normal with averages+ doses.

also don't drink it/ add the spirulina powder to a smoothie..the taste is very
acquired...its not terrible but easier to swallow tablets.

------
lawlesst
Dr. Valter Longo, who was an author of this study, was on the Diane Rehm Show
in January of 2014 with others discussing the benefits of fasting. All the
panelists endorse fasting to some extent but it was a lively discussion that
summarizes some his research as well as related research that advocates for
shorter fasting periods.

[http://thedianerehmshow.org/shows/2014-01-09/latest-
research...](http://thedianerehmshow.org/shows/2014-01-09/latest-research-
intermittent-fasting-0)

------
themodelplumber
Looks like this is the study:
[http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3608686/](http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3608686/)
(Edit: Nope, see reply below)

Interesting conflict of interest (edit: _potential_ conflict) with the
researcher being the founder of a food supplement marketing company.
[http://en.wikipedia.org/wiki/Valter_Longo](http://en.wikipedia.org/wiki/Valter_Longo)

Edit: I was wondering what the fasting + supplement connection was. Here we
go:

"L-Nutra's first line of products stems from 15 years of research by Prof.
Longo and his team at the USC Longevity Institute, one of the world's leading
centers for research on aging and its translation into human interventions
that optimize longevity and healthspan. It was largely motivated by the
request of many patients who wanted to _take advantage of the potential
beneficial effects of fasting during cancer treatment but were unable to fast
and forego any all meals or and snacks_." (Emphasis mine)

From:
[http://www.l-nutra.com/index.php/about/team](http://www.l-nutra.com/index.php/about/team)

~~~
MartinMond
The study you linked is from Feb 8, 2012.

I think this is the actual study: [http://www.cell.com/cell-stem-
cell/abstract/S1934-5909(14)00...](http://www.cell.com/cell-stem-
cell/abstract/S1934-5909\(14\)00151-9)

~~~
themodelplumber
Looks like you're right. Thanks!

------
mmastrac
If you're interested in this, watch Michael Mosley's BBC program on this from
a few years back where he anecdotally had good results trying it himself:

[http://www.bbc.com/news/health-19112549](http://www.bbc.com/news/health-19112549)

"I stuck to this diet for 5 weeks, during which time I lost nearly a stone and
my blood markers, like IGF-1, glucose and cholesterol, improved. If I can
sustain that, it will greatly reduce my risk of contracting age-related
diseases like cancer and diabetes."

~~~
Renaud
He's still doing it now, although just in 'maintenance mode' doing it 1 day
per week instead of 2.

He's maintaining a website and has done a couple of books on fasting, and the
5:2 diet in particular: [http://thefastdiet.co.uk/](http://thefastdiet.co.uk/)

------
Osmoticat
Interesting, but until it's been independently replicated a couple of times, I
wouldn't recommend changing your lifestyle.

~~~
thethrows
True, we need to be able to reproduce and confirm technically that fasting
correctly is good for people. But you cannot simply ignore millenia of
anecdotal evidence that people who fast simply are more healthier. I find it
odd that it's now considered normal to stuff yourself all the time, when
historically before maybe a century ago it was considered totally normal to
not eat all the time(involuntarily or otherwise).

~~~
solarmist
What millennia of anecdotal evidence? I've heard claims like that before, but
never seen the source of any of these claims. Really? In the past it was
common not to eat, voluntarily? That seems hard to believe with how central
food is to every culture I've ever been exposed to. In fact you are seen as
odd if you choose NOT to partake when others are.

If this is common knowledge to you it is certainly not for me, which is why I
do want to see the results of studies like this that have been replicated.

My entire historical perspective on fasting is from religious/spiritual
perspective which don't mention anything about health benefits.

~~~
wtbob
> In the past it was common not to eat, voluntarily?

Pretty much every religion of which I'm aware has the concept of fasting, and
on every culture people terms to make an attempt to follow their religion's
strictures (c.f. all the folds you see running at the gym).

Sure, as you more religions don't tend to mention the _physical_ health
benefits, but they certainly believe in the psychological health benefits.
Regardless of whether they believe in them or not, such regimens will affect
their participants' health for good or for ill.

~~~
solarmist
Really? My understanding of religious fasting was it was a form of devotion.
To show how dedicated you were to that cause. Or to show that you could
overcome your biological instincts.

In other words to demonstrate fortitude, strength of will, and discipline, and
thus become closer to an ideal that is mostly considered non-biological or
rather transcend the biological (God/Nirvana/etc). Or to empathize with
suffering/deprivation of others.

So, while I guess those could be considered benefits, I don't really see it.

~~~
agumonkey
Funny, I'm not religious and from my distanced POV I never took fasting as a
sign of devotion, more an old fashioned detox/cleanse with a sense of
minimalistic life (which is not far from empathizing with deprivation).

------
cheepin
This is mostly unrelated to the title, but for those of you wondering what the
limit of fasting is, an interesting study on a very obese man had him on water
and vitamins for over a year
([http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2495396/pdf/post...](http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2495396/pdf/postmedj00315-0056.pdf)).

The 3 meals a day rhetoric has been widespread (some even advocating even more
than that), but it seems a bit overblown.

------
IvarRafn
If anyone's interested in fasting I recommend watching this documentary from
BBC Horizon.

[http://www.dailymotion.com/video/xvdbtt_eat-fast-live-
longer...](http://www.dailymotion.com/video/xvdbtt_eat-fast-live-longer-
hd_shortfilms)

------
ThomPete
Previous discussion

[https://news.ycombinator.com/item?id=7858000](https://news.ycombinator.com/item?id=7858000)

------
arunitc
I have been trying intermittent fasting for the past three weeks - finish my
dinner by 7 and breakfast the next day at 11 or 12. Initially it was
difficult, but you get used to it quite fast. One thing I have noticed is my
afternoon drowsiness has completely disappeared. I used to feel extremely
lethargic and just couldn't put my mind to anything. Now I'm completely alert
and my productivity has increased dramatically.

------
vijayboyapati
I wonder if similar benefits can be had by practicing the method of "lean
gains" aka "intermittent fasting", or whether this only works with 3 days of
fasting, which is a long time to go without food. I'd certainly find it hard
to be productive during that extended period.

~~~
rsync
Everybody is different, and my anecdote should have very little weight
attached to it, but ...

I do an 18 hour fast once per week, which is a very modest fast. On the other
hand, I have a very, very comprehensive and intense exercise regimen, so my
resting metabolic rate is quite high, and 18 hours with _zero_ calories clears
my body out very thoroughly.

And I notice it greatly - it feels fantastic. I feel very quick and light on
my feet. It's noticeable.

Am I improving my immune system ? Who knows. However, it is definitely less
than a 3 day fast, and it definitely improves my health.

------
mingabunga
I've been eating once a day for the past 3.5 years and I'd read about the
supposed immune system benefits. I've not had a cold/flu since then and I used
to get 3-4 a year, so I'm sticking with it and I've become used to it anyway.

~~~
barbarian
Another of my kind! I've been eating once a day for about 2 years now.

This is obviously just anecdotal, but for me, I certainly feel more mentally
alert during a fasted state; though I wouldn't say I've been sick any more /
less than other times in my life.

Friends think I'm quite bizarre for eating this way - but it just seems to
work for me.

~~~
swombat
When do you eat that one meal of the day, and what does it typically consist
of?

I've been doing something similar over the last few months - a very light
breakfast, a solid lunch, and then no dinner - but for me, doing this was with
the purpose of losing weight - which did happen, at the rate of just under 1
kg a week.

~~~
mingabunga
I eat dinner only, quite a lot for dinner and I can graze for the rest of the
night. I like going to bed with a full stomach. I don't really get hungry
during the day, drink plenty of water and exercise at 3:30, then I'm hungry
after that. I eat most stuff, but keep pretty low on sugars, starchy stuff and
eat more fat than most.

------
bsdsailor
I participated in the eastern orthodox church (Christian) for a few years and
was introduced to their fasting (no meat or dairy products, and eating small
amounts). First timers are advised to start slowly (omit one thing) and
gradually get to full fasting. The typical fasting schedule is to fast on
Wednesday and Friday (with a couple of exceptions) of each week. There are
also long fasting periods before Easter and Christmas (and 2 or 3 shorter
fasting periods).

Initially, it was quite difficult but over time became much easier. Over time
I lost some weight (although that was not an objective) and generally began
feeling healthier and more energetic.

------
MartinMond
Article is from Jun 5 2014, here's the University of Southern California's
article: [https://news.usc.edu/63669/fasting-triggers-stem-cell-
regene...](https://news.usc.edu/63669/fasting-triggers-stem-cell-regeneration-
of-damaged-old-immune-system/)

------
DavidWanjiru
This sounds like hooey to me. I mean, fasting may trigger some
survival/distress mode mechanisms, but do such triggers actually consist
better health? All other things being equal, to the the extent that you can
experimentally make all the other things equal in this case, would I have a
higher overall white blood cell count after fasting than I had before fasting?
Does fasting (starving?) weaken my immune system initially? To what extent? Is
that extent recovered, and exceeded, by the new WBC production that wouldn't
have been triggered otherwise? I'm comparing this, admittedly based on zero
evidence, with the flight response. Adrenaline makes me run faster, but it
doesn't make me a faster runner. That's how I mean when I say this sounds like
hooey. Of course, I could be totally wrong, and I really have no basis to make
this claim in the first place.

------
thatusertwo
Once I fasted for 3 days, only drinking water. By day two I was pretty weak,
afterwards I recovered pretty quickly. The point being, it shouldn't be to
difficult to do if you aren't going to need to be too active.

~~~
loceng
I've fasted for 2-3 day periods where I was generally as active as I'd
normally be, including doing a few demanding 60 and 90 minute yoga classes
during that time. The only thing I really noticed was that if I exerted myself
above a certain level, such as walking at too fast of a pace, then I'd very
quickly feel tired - all it took was reducing my walking pace and I felt fine
again; I presume this is related to the different rates of energy being made
available.

~~~
junker37
After seeing this article the first time, I decided to try the 3 day fast as
well. I too continued my normal morning 3 mile runs and noticed that if I
couldn't push the pace for very long. I'm just an anecdote, but my immune
system seems to be stronger this winter. With two little ones who've been sick
a couple of times and a wife that had the flu, I've been able to get by with
just minimal congestion.

------
Mz
From what I have read, the gut constitutes about 70% of the immune system. And
in alternative med circles, it is pretty well known that digestive enzymes in
pill form can also be used as antivirals (something I have done with
prescription digestive enzymes). The gut, like the respiratory system, is
lined with mucus because it needs to manage a complex process of letting in
things the body requires for life while screening out things that are
dangerous.

So, if the conclusions of this study are at all accurate, perhaps part of the
mechanism is that fasting reduces the load on the system for a time, reduces
the amount of sorting out which foreign material to use as building blocks and
which foreign material to treat as dangerous invaders so it can put resources
to other uses.

------
cubano
I hate the fact that this study seems to be tainted with _potential_ conflict
of interest as outlined by @themodelplumber.

I wish science could get back to just-being-science and focus on provable,
repeatable results sans corporate involvement, as I think if this is really
true, it could be a real breakthrough.

I have some experience with fasting, and was always surprised how good I felt
after a couple of days, and to be honest the times I was actively living a
fasting lifestyle, I do not remember ever getting sick.

Yes yes I know...a big bag of confirmation bias and anecdotal evidence, which
is why I hope deeper, hard-science studies will continue.

~~~
misiti3780
I read Antifragile + The Black Swan once every year to remind me of this - and
everytime I read something I think about confirmation bias and silent
evidence. they are not tough concepts, but the human brain isn't really weird
to think that way - unfortunately (as talked about in Thinking Fast and Slow
also)

Taleb, for all his faults, is really good at calling out people for scientific
research that contains conflicts of interest - he has been calling out GMO
related stuff for the past two or three months on Twitter, before than he
became famous for doing it in Finance

~~~
jweir
Taleb is also an advocate for fasting.

[https://m.facebook.com/permalink.php?story_fbid=101521750395...](https://m.facebook.com/permalink.php?story_fbid=10152175039588375&id=13012333374)

------
junto
Does anyone have any links to suggested fasting regimes that they found
useful? How often to fast for example?

------
amelius
Could this also be used as a viable technique to approach auto-immune diseases
like Sjogren's?

------
knappador
The word "regenerate" has got to be a bit of a stretch. It's not like decades
of DNA mutations are going away.

I've done fasts on relatively nothing for over five days. Early on, you get
some "empty-stomach intelligence" where your mind is just more alert because
of plenty of oxygen (from not digesting) and probably some evolution that
favored apes that got observant and driven when hungry as opposed to lazy.

Fasting long enough to get the effects in the paper will use up all your
glycogen stocks. Read wiki on starvation for details, but basically you want
to have a small supply of starches to keep your skeletal muscle from breaking
down to feed your brain. About two days in, without some glucose supply, you
will unavoidably slow down. Lethargy will commence when your brain is
starving. It is not euphoric. It is the world slipping out of grip without you
noticing.

As long as your taking care of your mandatory glucose supply, fasting over
three days or more will lead to a common theme in all nutrition and health
papers: all processes that break things down for re-use are up-regulated and
all processes that consume resources are down-regulated.

It's not difficult to propose that a system composed of mostly brand-new,
turned over cells and muscles with all their proteins aligned to the principle
stresses is more protein efficient than one resulting from plenty of nutrients
floating around like entrepreneurs with too much money. Fasting would be
expected to result in general house-cleaning so that protein that's not
accomplishing much ends up reallocated to doing something useful.

Some examples of where this shows up in scientific papers is the increased
sensitivity to chemotherapy of cancer cells when the patient is fasting. One
proposed mechanism was an up-regulation of registration for immune-system
induced self-destruction through the normal pathway; a badly functioning
protein might go ahead and function sufficiently in the up-regulated pathway.

More obvious benefits from fasting are the same as those of anything where you
build up self-discipline and also getting in touch with the difference between
hunger and a lack of being full; they are much more distinct after a fast.
Cravings for sugar are gone because your hormones for hunger and satiety are
all operating properly, as is your pancreas.

My favorite way to get empty is to just drink water and/or coffee (black) or
tea. Fluids, no macro-nutrients. Get some glucose from some bread. Get some
micro-nutrients from some yogurt and rabbit food. Let the rest slip into the
starvation mode. Stress level and blood pressure will decline into a kind of
euphoria as long as you don't over-do the calorie starving to the point that
you're thinking on muscle protein.

I've done it. All the mechanisms have obvious symptoms. If you are just
ketogenic and in starvation, you feel euphoric and completely without
variations in energy. If you are beyond starvation and skeletal protein is
being converted to glucose, you piss dark yellow and feel like you're on
anesthetic. Either way you lose a lot of weight, your energy will regulate
much more tightly, and you won't be bothered by hunger, and you'll be drinking
coffee as nature intended it instead of some holiday special milk-shake.

It's well-established that reduced calorie diets promote longevity and that
the spectrum of metabolic syndrome conditions are associated with all sorts of
bad things, so although I'm not a doctor, I don't expect to have any regret
about recommending anyone try coffee fasting to put their system through its
paces.

~~~
beagle3
> basically you want to have a small supply of starches to keep your skeletal
> muscle from breaking down to feed your brain

But starvation in a healthy person takes 10-40 days to kick in, with 30 days
being way more common than 10. Before that, you're just ketogenic.

Everything I read, and my personal experience, leads me to believe that the
only muscle that breaks down is that which is not used (which is compatible
with your general description). As long as you keep exercising during the
fasting days, there's no reason to resupply your glycogen stores. After about
two days, your body will switch to ketones as a fuel source, which will likely
alter your body odour and -- if you are not used to it, e.g. the first time
you do it, is likely to give you headaches and other flu like symptoms for a
couple of days. But no reason for starch intake.

~~~
knappador
Go correct Wiki.

------
ruben94
that means no water too ?

~~~
yourapostasy
Usually a fast means you can drink non-caloric liquids, water being the
preference. There are many different kinds of fasts, and some are less strict
than others, but for the most part water is allowed in all of them.

------
mknits
Forget the study, people belonging to Jainism know this for centuries.

[https://en.wikipedia.org/wiki/Jainism](https://en.wikipedia.org/wiki/Jainism)

~~~
UserRights
No reason to downvote this guy, he has a valid point. Scientists should look
at the wisdom of people.

~~~
jstanek
It's important to remember that anecdotal evidence is not scientific in any
way. Just because there exists "peoples' wisdom" doesn't mean that this wisdom
is correct. This is why science exists in the first place, to explore and
explain natural phenomena.

~~~
bikamonki
Sometimes science is not a discovery endeavour, sometimes it just 'explains'
something that we already 'know'; that knowledge may be the product of
accumulated experience, intuition, observation or mere chance. It seems valid
then, to highlight an old religious ritual like fasting as evidence that such
practice works to improve physical health. Do note that the writer of this
comment is an atheist.

------
dschiptsov
Boy, we could cut spending on feeding patients in hospitals.

------
rjurney
I didn't read the study, but what definition of fast are they using? Water
only?

------
fesja
It's not so surprising to me. When you have stomach ache, the first thing they
tell you is not to eat until you have been cleansed. We have always done that
in my family. Also, once that I had a weird allergy on my skin (I'm not
allergic to anything) I fasted for 4 days drinking Aquarius and some ham and
rice the last 2 days. I didn't need any pills.

