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I remember I read something about fasting for >48h have an impact on your immune system (some call it reset?) where cells are replaced. Could that have a posit

I remember I read something about fasting for >48h have an impact on your immune system (some call it reset?) where cells are replaced. Could that have a positive impact on damaged cell genomics?

mgsouth 4y ago
Cells are, of course, replaced all the time [0]. For example, certain white blood cells every 2-5 days. In general metabolic processes slow down when fasting. Immune cell replacement doesn't reset your immune system; that would be a very bad thing, no? You'd suddenly lose all resistance to everything you'd been exposed to or vaccinated against. A quick internet search shows a PR piece from USC, "Fasting triggers stem cell regeneration" [1]. I'm not impressed. The article says "it is the first evidence of a natural intervention triggering stem cell-based regeneration of an organ or system," implying no previous study has ever shown such an effect, and it certainly isn't generally accepted as a biomedical effect. I don't know if the study results have been replicated. What the study's actual data said was "long periods of not eating significantly lowered white blood cell counts," which in mice was followed by a rebound when fasting ending. The researcher's interpretation was that he "likens the effect to lightening a plane of excess cargo." [Yeah! Let's temporarily get rid all those pesky unneeded white blood cells!] So my interpretation is that the white blood cells died off after a few days, as normal, and fasting interfered with their replacement. Fasting stopped, and replacement recommenced. I don't really get the popularity of quackish theories about fasting, "cleanses," etc. There's already a perfectly good regeneration system--it's called sleep. I guess it's like weird ideas about "oxygen-free copper" and such in audio circles. It's something to tweak, feeling like you're going above-and-beyond, but without actually being too difficult. [0] http://book.bionumbers.org/how-quickly-do-different-cells-in-the-body-replace-themselves/ http://book.bionumbers.org/how-quickly-do-different-cells-in... [1] https://news.usc.edu/63669/fasting-triggers-stem-cell-regeneration-of-damaged-old-immune-system/ https://news.usc.edu/63669/fasting-triggers-stem-cell-regene...
chasil 4y ago
Fasting triggers autophagy, which can remove toxins and other harmful debris. https://en.wikipedia.org/wiki/Autophagy https://en.wikipedia.org/wiki/Autophagy
- mgsouth 4y ago
  I read the Wiki article. It describes autophagy in two contexts: 1. Normal operation, where proteins, organelles, and whole cells are recycled. 2. Autophagy can also result from cell starvation. Other sources ([1]) describe several methods of getting rid of or recycling cytoplasmic components: 1. Secretive--the cell kicks the garbage out. 2. Selective autophagic degregdation--the cell invites very specific components into a lysosomes, where it digests it. "For example, the cell can use selective autophagy to degrade unfavorable components, such as damaged organelles and pathogens. In these cases, the cell uses autophagy mainly for clearance (to prevent certain cellular components from causing further harm), but not for the degradation products gained from this process." Also, "One example of autophagy in clearance is the removal of oxidized biomolecules (proteins, DNA, and lipids) when the cells are under oxidative stress." Note that reducing (de-oxidizing) stuff requires an energy input. 3. "In contrast, during nitrogen or amino acid starvation, the cell needs to acquire amino acids by degrading and recycling existing materials in the cell via autophagy. In these cases, it is the recycling function that is more important to the cell, and this is the main function of autophagy that most people envision when considering this process." In section 2.1, the paper describes pathways different than those for selective degredation for non-selective degregdation. The point is that that starvation-induced autophagy does not take out the garbage. It's a desperate canabalistic triage exercise; anything not essential to keeping the lights on is shut down and digested. It would be like a lizard shedding its tail and eating it. (AFAIK that doesn't actually happen.) Eventually those perfectly-good organelles are going to need replacing. Another analogy would be a startup running out of funding. It might fire all the customer-support folks, beef up sales and marketing, throw engineering into feature-of-the-week firefighting mode, and let the tech debt pile up to astronomical proportions. Eventually, if they survive, all that will have to be replaced, at great cost and turmoil. It is not a beneficial excercise. [1] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9313301/ https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9313301/
throwawaycities 4y ago
Fasting has multiple metabolic and cellular impacts. As another commenter noted fasting triggers autophagy (self eating) where cells use parts/proteins from dead cells to repair themselves. The research and work done in this field won a Nobel prize. As you note cells constantly die and are replaced but this replication is where a lot of poor genetic code can get copied into the new cells. One of the interesting things about autophagy is that through cellular repair cells actually live longer and don’t need to be replaced as often, this longevity and health of the cells appears to result in overall longevity and health of the subject.
mgsouth 4y ago
I want to appologize for my rant about "quackish theories". While it is true that pursuit of truth and rejection of falsehood is a very grave responsibility, it is a personal responsibility. Ranting is, at best, an attempt to force someone else to change how they discharge one of their responsibilities. That's even worse. (And to be honest, rants usually involve a lot of "look how smart I am.") Also, I had not considered that cleansing ceremonies have a very, very long history. There is a powerful psychological draw to them. Even "oxygen-free copper wires" could, in a way, be considered one form of that. :) Edit: The question was an honest one. It certainly didn't deserve me going off, and it's unfortunate that some have also expressed disapproval of it.

I remember I read something about fasting for >48h have an impact on your immune system (some call it reset?) where cells are replaced. Could that have a positive impact on damaged cell genomics?

mgsouth 4y ago

Cells are, of course, replaced all the time [0]. For example, certain white blood cells every 2-5 days. In general metabolic processes slow down when fasting. Immune cell replacement doesn't reset your immune system; that would be a very bad thing, no? You'd suddenly lose all resistance to everything you'd been exposed to or vaccinated against. A quick internet search shows a PR piece from USC, "Fasting triggers stem cell regeneration" [1]. I'm not impressed. The article says "it is the first evidence of a natural intervention triggering stem cell-based regeneration of an organ or system," implying no previous study has ever shown such an effect, and it certainly isn't generally accepted as a biomedical effect. I don't know if the study results have been replicated. What the study's actual data said was "long periods of not eating significantly lowered white blood cell counts," which in mice was followed by a rebound when fasting ending. The researcher's interpretation was that he "likens the effect to lightening a plane of excess cargo." [Yeah! Let's temporarily get rid all those pesky unneeded white blood cells!] So my interpretation is that the white blood cells died off after a few days, as normal, and fasting interfered with their replacement. Fasting stopped, and replacement recommenced. I don't really get the popularity of quackish theories about fasting, "cleanses," etc. There's already a perfectly good regeneration system--it's called sleep. I guess it's like weird ideas about "oxygen-free copper" and such in audio circles. It's something to tweak, feeling like you're going above-and-beyond, but without actually being too difficult. [0] http://book.bionumbers.org/how-quickly-do-different-cells-in-the-body-replace-themselves/ http://book.bionumbers.org/how-quickly-do-different-cells-in... [1] https://news.usc.edu/63669/fasting-triggers-stem-cell-regeneration-of-damaged-old-immune-system/ https://news.usc.edu/63669/fasting-triggers-stem-cell-regene...

chasil 4y ago

Fasting triggers autophagy, which can remove toxins and other harmful debris. https://en.wikipedia.org/wiki/Autophagy https://en.wikipedia.org/wiki/Autophagy

mgsouth 4y ago
I read the Wiki article. It describes autophagy in two contexts: 1. Normal operation, where proteins, organelles, and whole cells are recycled. 2. Autophagy can also result from cell starvation. Other sources ([1]) describe several methods of getting rid of or recycling cytoplasmic components: 1. Secretive--the cell kicks the garbage out. 2. Selective autophagic degregdation--the cell invites very specific components into a lysosomes, where it digests it. "For example, the cell can use selective autophagy to degrade unfavorable components, such as damaged organelles and pathogens. In these cases, the cell uses autophagy mainly for clearance (to prevent certain cellular components from causing further harm), but not for the degradation products gained from this process." Also, "One example of autophagy in clearance is the removal of oxidized biomolecules (proteins, DNA, and lipids) when the cells are under oxidative stress." Note that reducing (de-oxidizing) stuff requires an energy input. 3. "In contrast, during nitrogen or amino acid starvation, the cell needs to acquire amino acids by degrading and recycling existing materials in the cell via autophagy. In these cases, it is the recycling function that is more important to the cell, and this is the main function of autophagy that most people envision when considering this process." In section 2.1, the paper describes pathways different than those for selective degredation for non-selective degregdation. The point is that that starvation-induced autophagy does not take out the garbage. It's a desperate canabalistic triage exercise; anything not essential to keeping the lights on is shut down and digested. It would be like a lizard shedding its tail and eating it. (AFAIK that doesn't actually happen.) Eventually those perfectly-good organelles are going to need replacing. Another analogy would be a startup running out of funding. It might fire all the customer-support folks, beef up sales and marketing, throw engineering into feature-of-the-week firefighting mode, and let the tech debt pile up to astronomical proportions. Eventually, if they survive, all that will have to be replaced, at great cost and turmoil. It is not a beneficial excercise. [1] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9313301/ https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9313301/

throwawaycities 4y ago

Fasting has multiple metabolic and cellular impacts. As another commenter noted fasting triggers autophagy (self eating) where cells use parts/proteins from dead cells to repair themselves. The research and work done in this field won a Nobel prize. As you note cells constantly die and are replaced but this replication is where a lot of poor genetic code can get copied into the new cells. One of the interesting things about autophagy is that through cellular repair cells actually live longer and don’t need to be replaced as often, this longevity and health of the cells appears to result in overall longevity and health of the subject.

mgsouth 4y ago

I want to appologize for my rant about "quackish theories". While it is true that pursuit of truth and rejection of falsehood is a very grave responsibility, it is a personal responsibility. Ranting is, at best, an attempt to force someone else to change how they discharge one of their responsibilities. That's even worse. (And to be honest, rants usually involve a lot of "look how smart I am.") Also, I had not considered that cleansing ceremonies have a very, very long history. There is a powerful psychological draw to them. Even "oxygen-free copper wires" could, in a way, be considered one form of that. :) Edit: The question was an honest one. It certainly didn't deserve me going off, and it's unfortunate that some have also expressed disapproval of it.