---
title: 'Could This Be the Real Reason Fasting Works? | Christian Drapeau'
source: 'https://youtube.com/watch?v=hNI7mZ6Anlc'
video_id: 'hNI7mZ6Anlc'
date: 2026-08-04
duration_sec: 861
---

# Could This Be the Real Reason Fasting Works? | Christian Drapeau

> Source: [Could This Be the Real Reason Fasting Works? | Christian Drapeau](https://youtube.com/watch?v=hNI7mZ6Anlc)

## Summary

In this interview, stem cell scientist Christian Drapeau explains the human body's repair system, which relies on stem cells, and how its decline with age is the fundamental cause of aging. He discusses the parallels between the immune and repair systems, the impact of bone marrow conversion, and the potential of fasting to rejuvenate stem cells.

### Key Points

- **The Body Has a Repair System** [01:01] — Christian Drapeau explains that the human body has a repair system analogous to the immune system, which is not yet part of standard medical curriculum. This system is responsible for healing injuries and maintaining tissue integrity.
- **Immune System Response to Injury** [02:01] — He describes how the immune system responds to a cut: local immune cells detect bacteria, engulf them, and present remnants to lymph nodes, triggering a systemic immune response that targets the infection site.
- **Stem Cell Mobilization After Injury** [02:56] — After significant injuries like heart attacks or fractures, compounds released by immune cells signal the bone marrow to release stem cells. These stem cells can increase up to 10-fold within 3-5 days, circulate, and migrate to the injured tissue to promote repair.
- **Aging and the Repair System** [04:35] — The repair system declines with age more dramatically than the immune system. By age 15, 50% of red marrow is lost; by age 30, 75%; by age 35, only about 10% of original stem cells remain. This decline leads to slower recovery and increased aches and pains.
- **Why Stem Cells Decline** [07:15] — Stem cells become fewer and less functional with age due to accumulation of cellular garbage and misfolded proteins. Autophagy, particularly through fasting, is effective in rejuvenating stem cells.
- **Evolutionary Perspective** [08:44] — Drapeau suggests that the decline in stem cell output is because humans evolved with a life expectancy of ~30 years, so a strong repair system wasn't needed beyond early 40s. Modern longevity extension is a new challenge.
- **Telomeres and Stem Cell Limits** [10:22] — Telomere shortening is natural and desirable for differentiated cells to prevent immortality. However, deep quiescent stem cells have minimal telomere attrition, and mobilizing stem cells does not deplete the reserve.
- **Reconverting Bone Marrow** [12:10] — Drapeau is interested in research to reconvert fatty marrow back to red marrow, which could be a major longevity breakthrough. Currently, red marrow reconversion is associated with leukemia, but he believes a healthy approach exists. Fasting (3-day) is known to rejuvenate stem cells and may aid reconversion.

### Conclusion

The interview highlights that the decline in stem cell function and number is a primary driver of aging, and strategies like fasting can help rejuvenate the repair system. Future research into bone marrow reconversion could unlock significant longevity benefits.

## Transcript

regenerative medicine with stem cell scientist Christian Drapeau, a published researcher who holds multiple patents in cellular regeneration and has spent over two decades proving that our internal stem cells are the ultimate defense
against human aging. So Christian, welcome back to Modern Health Spain and thank you so much for joining us today. >> My pleasure. Thank you, Richard. >> So Christian, we did speak uh about the amazing features of stem
cells and that was about 18 months ago, I think, and I will link to that above for anyone who wants to go back and look at the previous recording. So as a starting point for today, kind of to set the scene, what I'd like to do
stem cells. So I you have referred to the stem cells So I you have referred to the stem cells as kind of the repair system kind of in I know analogous to the immune system. So can you explain what you mean by
>> [clears throat] >> I understand that it feels almost like an analogy or a metaphor because if you graduate from college today in medicine or any sort of health sciences, uh you're not told that the human body
has a repair system. It's still not in the curriculum, if you want of the of the medical classes. Uh but in reality, physiologically, scientifically, the human body has a repair system just like is that it has
an immune system. Uh it I don't know why it is taking so long for this to really sink in and be incorporated into general medical knowledge, but but it is. And what I'm saying is not based on one, two papers. It's not an idea. It's a vast
scientific literature. So and and let's describe them side by side to kind of really see how similar they are in the way and as relevant. So you cut yourself. You have an opening, you have
that cut and then you start to have an infection. What is happening is that local immune cells will detect the presence of bacteria, will engulf some of them, will express on their membrane remnants of
that bacteria, will then be caught by the lymphatic circulation, be brought to the lymph node and the lymph node at the level of the lymph node your immune will see okay, there's an invader somewhere in the body and now the entire immune
system starts to ramp up. Now, these cells are released back in the blood circulation, they go everywhere in the body but when they get to that area where you have the cut, there's a signal that is telling them that's where the
problem is. They leave the circulation, they go into the tissue, they migrate beside the bacteria and then with various mechanisms will end up basically just killing these bacteria. That's your immune system.
Now, as you do this cut, the same thing. If the cut is significant, if the injury is significant, at the same time compounds are being released that are by immune cells to a large extent that will go to the bone marrow and will trigger
own stem cells. After a significant injury like a heart attack, bone fracture, burn to the skin, any a stroke, these are the models that were studied but let's say any significant injury.
The number of stem cells can go up to 10-fold within three to five days. Significant response. These stem cells circulate everywhere but when they circulate into the fine capillaries of the injured tissue, there's one specific
compound that is aimed that its job is to call stem cells. So, when stem cells circulate into the fine capillaries of the affected tissue and they encounter that compound, it triggers their migration out of the blood into that
tissue and upon contact with cellular debris of that tissue, stem cells will multiply and either transform into cells of that tissue or release compounds that will stimulate the tissue's resident stem cells or both. And then the tissue
will repair. Everybody has seen that in their body since the day we are born. Everybody has had a bone fracture, a cut, a bruise, something and we see that the body repairs. And so this is your repair system. Just
like we have an we have an immune system, we have a repair system. change as we age? Is is that the reason why we repair less
well? >> Exactly. Exactly. So >> Exactly. Exactly. So the immune system changes as we age, but but the repair system is by far I mean it changes magnitudes
over different from the immune system. So your repair system is your stem cells that are essentially made by red marrow in your bone marrow. So when we are born, red marrow is everywhere in our bones, but very rapidly it kind of
leaves the bone the center of the long bones, reaches the heads of the long bones and it slowly recedes through a process called bone marrow conversion. So your red marrow converts into fatty marrow or yellow marrow. These are fat
cells essentially. Some there there is still some production of stem cells from the fatty marrow, but it is much much much less. So as the marrow, the red marrow converts into fatty marrow and decreases
in volume in your in your bone marrow, then the output in terms of number of stem cells goes down. By age 15, you've lost about 50% of your red marrow. By lost about 50% of your red marrow. By age 30, about 75% of your red marrow,
and it it through a mech through a mechanism of inhibition from fat cells to a red marrow in your bone marrow, the output is that by age 30, 35, you're left with about 10% of the stem cells that you're born with.
And that's your repair system. So, this is why at some point in our 30s, we all discover before that we were Superman, Wonder Woman. Like, whatever you do, it doesn't matter. Uh people are telling you, "Take care of your health,
you know, you will lose it, you know, when you age." And when you're 25, 20, like like this has no meaning for you. And yet, in your mid-30s, you start to see you're not recovering recovering as well as as you used to. Small injuries
linger a little bit longer. You start to have like aches and pains. I mean, 30 is a little early, let's say early 40s, then it's there. You notice it in your body. This is a direct consequence of that gradual decline in your ability to
repair. And I'm working on a book right now where I'm laying out all the science. It continues in that decline in the ability to repair, or I should say failure of endogenous repair, is actually the fundamental cause of aging
>> Do we do we know why the stem cells the why you have less stem cells? Or or is it that the stem cells are less functional or there's less of them or
>> Both. It is both. So, they are less functional and they are less they're fewer as as we get older. Uh they get less effective just because like any other cells, you know, they accumulate garbage, dysfunctions,
misfolded proteins, stuff. Uh so, which means that autophagy is a very effective approach to rejuvenate stem cells. We know that fasting is probably the best thing to re-rejuvenate stem cells. But, why is this happening? I mean, I don't
have a great answer, but it but you know, there's a reason for all things. uh I think that it's simply because we have evolved over tens of thousands of years with a life expectancy of 30 years of age. So, the body never had an
of age. So, the body never had an opportunity to basically to need a strong repair system past, let's say, mid-30s, early 40s. Uh and the human body today is strong until early 40s. But historically, it was not needed
beyond that age. And if you also think about it, when you expand, by expanding I mean when you grow, uh childhood until late teens, as you grow, then you need a force of generation, which is or regeneration,
but it is your stem cells. So, you your output in stem cells is is is immense. But once you've completed that growth and you have now a mature human body, then you don't need that same ability. Now, the big question to me, for which I
don't have an answer, is that as we see in the scientific literature and all the studies that we're doing, as a 50-year-old, for example, if I just double the number of stem cells in circulation, which is still a fraction
of what you had when you were in your in your teens, if you double that, the impact on the ability of the body to repair is quite impressive. So, why is it that we did not evolve in a way where, you know, you you just a little
difference. And maybe the answer is just that evolutionary uh speaking, biologically speaking, we never needed it in our evolution. main the main I would think the main reason. Now, we have we have added 50
years to our longevity, and that's what we're dealing with. We're dealing with we're dealing with. We're dealing with additional lifetime, uh lifespan, that was designed to do that. So, we now we we try to leverage everything to give
extra 50 years, which is the whole purpose of biohacking. limit, like a theoretical upper limit to the number of stem cells
that you have? Um, I mean, you could see you've got a stem cell and if it doesn't have telomerase, then it can divide so many times until it hits the Hayflick limit. So, there would be like a theoretical upper limit.
Um, I mean, if I mobilize a a lot of stem cells, does that mean I have less left or does it work that way? >> No, it does not work like this. So, just to be clear,
telomere shortening is is a very natural process and you want it. You would not want a cell moving a stem cell moving into a tissue and becoming, let's say, a liver cell and that liver cell right now doing its function, being exposed to
doing its function, being exposed to toxin, doing its job to to be immortal because you know that at some point it will be damaged and it will create a problem. So, you want these cells to have a limited lifespan and that is
where you have shortening of telomeres. You do have some telomere attrition in stem cells, but it's not a phenomenon that is seen in your deep uh, dormant quiescent stem cells, which is really your deep bank of stem cells. So, so you
have a deep deep dormant stem cells deep in your bone marrow and out of this in your bone marrow and out of this emerges sort of faster duplicating stem cells that are your bank of stem cells that you need as you repair. And the
kind of increase in the release of stem cells that we're talking about today is nothing that would put a dent in this ability to repair. So, we can release them every day of our lives the way that we're talking about and it does really
have a negative impact in a in any way that we have seen so far. So, it sounds very much like the uh the thymus gland, right? The thymus
gland turns into fat and uh involutes. But, uh Dr. Faye has tried putting human growth hormone, and he seems to have recovered at least some of the
thymus capability. Is anyone looking at being able to recover yellow bone marrow back to red? like like everything that we're talking
about right now, I'm I'm really talking on this based on a lot of studies, but like often in science, there's a gap between everything that you see being published in the scientific literature, and that
being a coherent understanding that is applied in that is taught in academia and applied in clinical practice. We have not yet crossed that gap. So, we're in that process right now. But, yes, I think when all of this has
been fully understood for what it is, my next round of research, now I've I've spent a lot of time studying stem cell mobilization, but you know, if I have funds to do additional research, this is where I will go, reconversion of of the
bone marrow. I think that this would probably be the greatest development in longevity medicine. But, right now, the only like the the the sensitivity of the
whole issue is that there is a phenomenon that today is seen as reconversion of red marrow, and it's leukemia. leukemia. So, so, the way that today red marrow is
seen is a disease process. I am convinced, without having any data to show, that there's probably a way of reconverting the red the fatty marrow into red marrow in a way that is healthy or or
or slowing down that process of conversion so that we end up at 50 and 60 and I think more stem cells in circulation, but I'm not aware of any research that has been done on this. There is I found
one or two paper on a drug that was used and shown to do something like that, but nothing has been really developed with it. Today, as we speak, the only thing that to me is known to to to do this to an extent is fasting. Three-day fasting
has been shown to to rejuvenate your stem cells and might also lead to some version of reconversion, but very little data on it.