The surprising cause of fasting's regenerative powers

https://www.nature.com/articles/d41586-024-02700-2

by pseudolus • 2 years ago

47 62 2 years ago

So what's the surprising cause ? I couldn't find it after skimming the article twice.

thefz• 2 years ago

Breaking a fast carries more health benefits than the fasting itself, a study in mice shows1. After mice had abstained from food, stem cells surged to repair damage in their intestines — but only when the mice were tucking into their chow again, the study found

Literally the first paragraph

reportgunner3• 2 years ago

I still don't see the cause. Eating is the cause ? How is that surprising ?

jtbayly3• 2 years ago

The surprise is that the benefit isn’t gained until you start eating again. It’s not during the fast that good things happen, apparently.

mizzao• 2 years ago

The article actually seemed to suggest that eating after fasting increased the chance of "precancerous growths", which seems like "bad things".

dzsquared• 2 years ago

tldr; positively impacts stem cells making them more effective at repairing damage

azinman2• 2 years ago

Which also lead to tumors as polyamines are involved in cellular division.

zihotki• 2 years ago

.. in mice.

begueradj• 2 years ago

I read all sort of contradictory "scientific facts" about this subject. By the end of the day, listening and observing your body will provide you the right answer.

anotherhue• 2 years ago

Sure...but an interesting recent-ish development is that you're not only listening to your body, but to a enormous microbiome that is also signalling you towards its own ends (it's sugar, they always want sugar).

Here's a paper that talks about the pathway: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4367209/

rajnathani• 2 years ago

Not really about the sugar point. At times people crave savory or something high starch+fat based. For instance, little kids generally tend to crave for very sweet things but at times prefer something like pizza or pasta over something sweet (this is based on a personal second-hand observations). This is also the case for humans, for example during cheat days that people don't simply eat sweets (for example Dwayne Johnson finishing up something like 12 pizzas as one of the things on his cheat days).

lm284692• 2 years ago

Everyone is different that's for sure. I haven't eaten breakfast since I'm a teen and I mostly eat one meal a day for the last 10+ years

Everybody talks shit about fasting but nobody even bat an eye at "you have to eat three times a day, every day, at the same time, everything else is obviously wrong", which is at least as ridiculous

082349872349872• 2 years ago

Around here, the five mealtimes are morning-meal, 9 o'clock snack, midday-meal, 4 o'clock snack, and evening-meal.

On the other hand, I've been in a resort where they announced "merienda will be served between X and Y o'clock", which scandalised my local friends, who wondered aloud who'd ever heard of such sacrilege as eating merienda according to a clock and not your stomach.

My impression of historical practice is that people who had to go work in groups, in fields (or later in factories), tended to hew to traditional mealtimes. (there's a nice discussion somewhere on HN about how you don't want to stay in the fields between noon and one, or the "noonday witch" will get you...)

However, those who could afford it simply ate whenever they felt like (in at least two asian countries I know, it's considered a faux pas if there is ever a moment during the day when the main table doesn't have some sort of food on it).

The story I heard is that in the western context it was Louis XIV* who instituted mealtimes for rich as well as poor: his court was so large and so elaborate that logistics demanded the kitchen no longer be open, as it had been under previous monarchs, for courtiers to swing by at any hour they felt like grabbing some grub. True, or "Just So"?

* later, in the waning days of Austria-Hungary, the protocol at court dinners was that one did not continue eating dessert after the Emperor had finished with his. Of course, he had also been served first, so at some precedence level it must've always been a throw of the dice, whether one would even get served any Kaiserschmarrn before it was time to down forks.

RandomCitizen12• 2 years ago

Given that fasting is enshrined as a order in many belief systems, it seems like humans needs external motivation to ignore their body's complaints and fast for positive effects.

lm284692• 2 years ago

75% of adult in the west are obese or overweight because they listen to their body...

What we call fasting today was the defacto lifestyle for hundred millions of years. The current three meals a day pattern doesn't even register on that scale

anonyfox• 2 years ago

thats not always the right thing to do. drugs can mess with what you feel/want for example. we meatbags do have really bad sensors at times.

AndrewKemendo3• 2 years ago

Is there a name for the phenomena encountered with this particular response?

Specifically, I’m talking about when discussing extremely complex systems, ones that we don’t have full understanding of, there’s this tendency at a certain point of complexity to throw your hands up and say:

“because we can’t understand all of it perfectly then we can’t understand any of it and so just rely on these exceptionally loose grained impossible to define heuristics that have no comparability reference or baseline or anything meaningfully objective”

It’s like completely abandoning the concept of science measurement and just going full in with nothing matters we can’t measure it so do whatever you want.

Is it a failure of communication or is this an actual cognitive pattern that we can define?

It seems like a basic implementation of the all or nothing fallacy

roenxi• 2 years ago

I present to you the Wikipedia List of Cognitive Biases: https://en.wikipedia.org/wiki/List_of_cognitive_biases#Egoce... . There is a lot of overlap on a topic like this, but probably something like the "Illusion of validity".

That being said, listening to your own body is not a bad strategy. The nervous system evolved in tandem with this particular extremely complex system and is arguably purpose-built to keep it in good working order.

tekla• 2 years ago

Engineering.

jtbayly3• 2 years ago

Is there a name for the phenomena encountered with this particular response?

Specifically, I’m talking about when discussing extremely complex systems, ones that we don’t have full understanding of, there’s this tendency to ignore the huge gaps in our knowledge and deny that individuals can know anything objectively about how their body responds to things, even though science has no explanation for it…

kiba• 2 years ago

Science is a good guide, on a population level. It is up to the individuals to customize the guidance to what works for them.

jauntywundrkind• 2 years ago

Faith based reasoning.

A pox upon it's house!

It's well and good to listen to your body. Observation and insight is humankind's great boon. But man, the science nihilism & belief you can just think about it and come up with better understanding than the world's greatest doctors & researchers is astounding & a massive boat-anchor that threatens to drag humanity down below the waves. Awful.

svnt2• 2 years ago

Complexity-matching.

You have one complex adaptive system with a simplified interface to another complex adaptive system and you leverage that to understand the first, where trying to reduce it to a toolkit that you can internalize is impossible due to the finite nature of your cognition.

OP is like your ancestors trying to predict the arrival of game in the spring and relying on a certain flower blossoming.

Yours is trying to arrive at a working calculation involving the time from the winter solstice combined with the daily sun exposure, thermal gain, precipitation, and biennial changes in major weather patterns, etc, leading to the possible but not certain generation of a new complex system that must be sustained by a population of humans and might not ever work as well.

In many instances, your perspective is the more questionable one.

dataflow• 2 years ago

Underfitting?

namaria6• 2 years ago

The response to 'science is confusing' should never be 'ignore science'

taeric5• 2 years ago

Fair, though I think a charitable read of the advice would be not to wait for a complete consensus in science before living your life.

tsimionescu3• 2 years ago

It's not "science is confusing", it's "science can't tell us anything definitive about this subject yet". Science is a process, not an artifact. Finding two conflicting papers on one subject and deciding to ignore both is not "ignoring science", it's ignoring two conflicting results that science is still working through.

llm_trw• 2 years ago

Yeah, which is why you should always eat leaded paint. How can something so sweet be bad for you?

sl-1• 2 years ago

Interesting, but I would be careful to generalize from mice studies

Shadowed_• 2 years ago

After mice had abstained from food

Yeah, right, mice abstained from food. Mice don't abstain from food. You didn't feed them!

delichon• 2 years ago

Nice catch. This is a step worse than hiding the actor as in "the mice were sacrificed." It flips the whole script as in "the mice (heroically) sacrificed themselves (for science)."

Amorymeltzer• 2 years ago

The actual paper (paywall): https://www.nature.com/articles/s41586-024-07840-z

bilsbie• 2 years ago

I tried one meal per day for three weeks and I had to quit because my heart would start racing after my meal.

Really bizarre. I couldn’t find any information.

naasking• 2 years ago

Interesting, increased heart rate after eating is not uncommon [1]. Could be a sudden influx of glucose after fasting kicking a lot metabolic functions into gear.

[1] https://www.healthtoday.com/be-healthy/heart-health/why-does...

TimSchumann4• 2 years ago

I haven't had that experience, but I usually do longer fasts.

My go to for this would be electrolyte levels, which can vary heavily depending on water intake, diet, exercise, supplementation, etc.

Here's some journal articles I found based on a quick search.

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1364615/ https://pubmed.ncbi.nlm.nih.gov/8777833/ https://link.springer.com/article/10.1007/s002280050682

Be interested to hear if something in one of those pops out at you.

mactavish882• 2 years ago

Were you supplementing with electrolytes while fasting? Don’t have any studies at hand right now, but fasting apparently causes you to quickly lose fluid and electrolytes.

I recently started doing 5:2 fasting and noticed on the day after fasting that I tend to get bouts of pretty bad orthostatic hypotension. Supplementing with a zero-calorie electrolyte on fasting days and the day after helped mitigate this.

gadders• 2 years ago

I lost 15kg by tracking calories and eating one meal a day in the evening. The rest of the day was filled with coffee and an apple for lunch.

I've pretty much stuck to one meal a day now. Lunch is still something light, like a protein bar or an apple. The only time I really eat breakfast now is if I'm on holiday and it's included...

crazygringo• 2 years ago

Probably the sudden spike in blood sugar from carbs. Your blood sugar was lower the rest of the day, so the carbs all at one feels like if you are three sugary candy bars in a row.

I've had a lot of success with OMAD for weight loss and improved attention, but it's a lot more protein and fats and veggies. And I make sure the starches I eat are slow-digesting like pasta, not fast-digesting like bread or any sugary desserts.

tu7001• 2 years ago

Are there any other studies in the topic except on mice?

TimSchumann4• 2 years ago

Generally the answer is 'no' to that question.

Medical ethics tends to prohibit it, especially in a clinical setting. It's seen as doing harm to the patients, which physicians tend to frown on.

I've even heard of some papers on fasting, retrospectives -- which I think aren't technically studies but an aggregation and analysis of patient data, collected from events that have already happened, which patients voluntarily undertook -- that were banned from journals because the results may have 'encouraged harmful behavior.' Don't have any sources on that and it's a memory from like 6-8 years ago though.

mactavish882• 2 years ago

For those potentially concerned about cancer risk from breaking fasts, from the article itself:

Researchers should always be concerned about anything that could cause cancer, but Valter Longo, a biogerontologist at the University of Southern California in Los Angeles, says that mice with the tweaked genes were “almost doomed to get cancer”, and that the slight rise in risk found in this study might not be applicable more broadly. For example, he points to a study he published in 2015 that found a 45% reduction in abnormal cell and tissue growth in mice that fasted compared with animals that did not.

The mice that developed precancerous growths were genetically modified to be prone to such cancerous development.

TimSchumann4• 2 years ago

Yeah, all the research I've read says that fasting is actually preventative when it comes to cancer -- and possibly assists with starving out cancer cells during treatment of the disease.

TimSchumann4• 2 years ago

Interesting post to wake up to when I'm 7 days into a fast.

Glad to be getting back into extended fasting, sad that I, again, have the body type that makes it somewhat of a requirement health wise.

The surprising cause of fasting's regenerative powers

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