Three day fasting - kickstarts the immune system? - CLL Support

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Three day fasting - kickstarts the immune system?


There's a trending theory that fasting for three days forces your system to "reboot", flushing out and renewing the white blood cells. 'm lucky enough to be "watch and wait" at the moment, so it won't do me any harm to try... Does anyone here have an opinion? Is it worth trying, or is it yet another fad? I

15 Replies

I suspect you are referring to this report or similar:

From the article: "During each cycle of fasting, this depletion of white blood cells induces changes that trigger stem cell-based regeneration of new immune system cells." but which immune system (white blood) cells? Note also that the article notes that Prof Longo's work is met with some scepticism by some "Britsh Experts". It would be great if this lengthy dieting selectively boosted neutrophils and other white blood cells, but not B-Lymphocytes, so I too was interested to read more about Prof Longo's findings. But when I tried to find a reference to a peer reviewed paper with those missing details, I frustratingly drew a blank. If someone has more success than me, I'd love to read the paper!

Do you really want more B-Lymphocytes, which are the white blood cells which are that part of the immune system that forms antibodies in healthy people, but will just add to our CLL? You could try the diet approach and see what influence it has on your different white blood cell counts, or you could wait for more research.

More on Prof Longo's lifelong research into the influence of diet on ageing and immunity:


I do not know enough to write this really ...but can find no peer reviewed journals on the topic either. So please forgive me writing from a position of ignorance.

This seems to me to fall into the same category as mega doses of vitamin C ... which I was told in this forum may boost the immune system, but this could potentially accelerate the development of CLL at the same time. I searched and searched for some studies/data on this and drew a blank.

It is very frustrating how little money/effort is put into the research of alternative approaches.

AussieNeilAdministrator in reply to MeTooAsWell

There is so much we still don't understand about the influence of different vitamins on CLL, but I don't fancy our chances getting answers when there is still no scientific consensus on whether megadoses of Vitamin C can improve the immunity of healthy people and protect them from catching the common cold, or reduce the length or severity of an infection.

The warning about Vitamin C possibly boosting the growth of CLL comes from Dr Susan Leclair, who is a hematology researcher and chancellor professor in the department of medical laboratory science at the University of Massachusetts. .Dr Leclair provides medical support for the CLL ACOR list and you'll find some excellent videos from her on understanding blood counts and ALC doubling time via Patient Power and Youtube.

I'm sorry that I can't find Dr Leclair's original response in the CLL ACOR archives, but her advice has been re-quoted on that and other CLL support sites as follows:

"Vitamin C does seem to stimulate lymphocyte activity - which was one of the reasons that Linus Pauling thought that it was so good in the prevention of malignancy. The flip to that, of course, is when the malignancy is in the lymphocytes and then it is not a good idea to stimulate them any further than already are.

One of the issues then is the fact that we all need vitamin C to live. So - what to do. I would stick with the printed recommended daily allowance and not go too high above that. Does that mean I don't gorge on fresh oranges when we get them? No - but I don't do it on a daily basis either."


"In essence, you do have that correct. vitamin C does stimulate the immune system and several researchers claim that too much of it can be harmful to CLL patients. If you google vitamin C and leukemia, you will get several hits about this. One very good overview is

Much of the work on anti-oxidants show that they have several different pathways of action. Is it possible that one of them MIGHT be better for patients with CLL than others? Possibly but that is unknown at this time.

I think that most researchers would still rely on the "balanced nutrition" rather than the skewed nutrition used by Pauling and others. (Remember, Pauling did die of cancer.)"

There is also this paper, showing that Vitamin C promotes T- Lymphocyte maturation:

Vitamin C Promotes Maturation of T-Cells (US National Library of Medicine, National Institutes of Health)

Then there's this interesting discussion on boosting your immune system from Harvard Medical School (promoting the sale of their book on the immune system which has a broken link!). The Be Skeptical paragraph is particularly interesting:

Note that the above link is for the genera public, NOT leukaemia patients.


A couple of VERY well-thought (and thought-provoking) responses. Thanks to you both.

Thanks so much AussieNeil.

If anyone wants to read the actual paper:

I'm not an immunologist or medical professional, just a fellow patient.

What I have doubts about is that fasting can somehow kill malignant B-cells. Such cells survive because the normal cell signalling that tells them to prepare to die (apoptosis) is defeated by mutations. So fasting would appear to kill more good cells than bad one, and shift the proportion in favor of the bad.

I would think that the stimulation of new cells would create both good and bad cells, and possibly give the bad cells a boost they surely don't need by stimulating growth factors.

But the life cycle of B-cells is wonderfully complex to behold, and I can imagine that some part of these observations might be useful after some kinds of therapy where the bad cells are knocked back almost completely. The proportion of good to bad is what would be the important factor, I think.


AussieNeilAdministrator in reply to SeymourB

Well done finding the paper! I've often wondered to what extent mouse models are applicable to humans, but at least findings like this in mice, provides an incentive to actually study if the same effect occurs in us. Given that the researches had a Flow Cytometry unit, it's a pity that they didn't see if there was a difference rate of regrowth by the different lymphocyte types. But as you point out, any benefit requires the bad cells to be knocked back first and more than good cells after regeneration, whereas with cancerous B-cells, they are more likely to survive the fasting cycle.

Perhaps prolonged fasting after chemotherapy might work, in which case, does that mean that patients that don't feel like eating for several days after chemotherapy due to bad nausea actually do better? That might be possible to assess by analysing patient records!


zevkalman in reply to AussieNeil

Actually a friend of mine David Eichler (a professor in a university in Israel) has done a lot of mouse model studies of cancerous tumors and finds that cancerous cells are more fragile to the environment than healthy cells. Lack of food prompts healthy cells to slow down and "wait out the fast" until food becomes available. Cancerous cells typically are always on steroids, and tend to do much worse when there is a lack of food (he found that protein and sugar is especially required by cancerous cells). So fasting should actually help in the fight against monoclonal B-cells. The same fragility applies to cancerous cells in extreme heat (hyperthermia)...the normal cells can slow down but not the cancerous cells. Here is a BBC article on my friend's research:

The article says that there are no clinical studies supporting this hypothesis, and this is basically correct, but there have been a lot of (currently unpublished) experiments with mice by Eichler and his colleagues, and these experiments fully support the fact that restricting calories, fasting, and eating a low-protein and low-calorie diet helps the mice fight cancer. Again, I am not recommending this kind of diet to anyone here (although I have recently become skinny since my diagnosis, and my blood work is doing great nowadays), but it should at least inform us to lose any excess weight we might have.

AussieNeilAdministrator in reply to zevkalman

Interesting insight into cancer cells zevkalman. Our cancerous B-Lymphocytes are definitely more fragile than normal ones - which is why it is common to see the comment "Smudge cells present" with out blood tests. Unfortunately they don't grow that much more rapidly than our healthy body cells - hence the 'Chronic' label and this is what makes CLL challenging to treat without highly targeted therapies. They are also very good at secreting themselves away in lymph nodes and the bone marrow and damp down T-cell activity to protect themselves from our body's innate ability to kill off cancer cells. These factors are part of why CLL has been historically so hard to treat, with significant treatment breakthroughs that hold the promise of extending our likely life expectancy with CLL only occurring relatively recently...

zevkalman in reply to AussieNeil

Hi Neil, of course I agree with you about everything you wrote, but until these significant treatment breakthroughs you speak about happen, I am convinced that caloric restrictions are something that should be discussed by everyone, especially those of us with compromised immune systems. Though we may not understand it scientifically, caloric restrictions do have a statistical basis in longevity. Here is a typical article from Nature on a study of monkeys:

And yes, I do believe based on scientific data that I have seen that caloric restrictions can significantly affect cancer outcomes in mouse models. I quoted the hypothesis that this may occur because of a healthy cell's ability to adopt to "famine" by simply going into a less active state, something that at least some cancer cells seem unable to do. Maybe our monoclonal B-cells can adopt to caloric restrictions as well as our healthy B-cells can, but certainly faster growing cancers like melanoma (that we CLL'ers need to be wary of) are probably aggressive, and it wouldn't hurt to try to diminish the ability of any mutagenic cells to propagate. Maybe I am also biased since I have worked for a few years in nuclear medicine, and when you see cancer cells in the breast lighting up like a Christmas Tree when you give the patient glucose tagged with a positron-emitter radio-tracer, you see in vivid color the hunger of cancer cells for sugar and other sources of energy.

AussieNeilAdministrator in reply to zevkalman

For some of us (self included), watch and wait is particularly hard to endure as we feel we need to be doing something to fight the progression of CLL. If we can safely fit prolonged fasting into our lifestyles without perhaps injuring ourselves in a car accident (say) because of reduced concentration, then this may be something we can try while monitoring the effect on our white blood cell lines. There are far, far more dangerous 'treatments' that cancer patients undertake!

this seems like such common sense and I would've thought that a three day fast would be quite stressful on the body anyway. It's just that us CLLers really want to help our beleaguered immune systems and will try anything.


Subject all mouse studies to a critical eye, the mouse's immune system and general physiology is not that close an analog of the human. You never really know what you've got until you stick it in a human (although monkeys can get you closer).

zevkalman in reply to Hidden

Here are some recent papers in the prestigious journal Nature on caloric restriction and longevity in rhesus monkeys:


And here:

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