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Fasting and Cancer ...

"Fasting and calorie restriction can slow and even stop cancer progression, tumour growth and metastases. Both can kill cancer cells and significantly improve chemo and radiotherapy effectiveness. Fasting has also been shown to boost the immune system, de-fat the liver and pancreas and significantly reduce chemotherapy side-effects. A fast is something to seriously consider when having chemotherapy - from three days before to the day after."

"Indeed, studies have shown that fasting for just three days can not only boost your immune system, but regenerate it entirely, helping to ensure a long and healthy life. The researchers who conducted the study described it as remarkable and a major breakthrough — no kidding! This study showcases how starving the body actually kickstarts stem cells into producing new white blood cells, which will then fight off infection."

(This is an intriguing idea. Part of the problem with CML treatment is that our TKI's do not target quiescent Leukemic stem cells (LSC) (they do attack dividing LSC's). So when we stop treatment, Leukemic stem cells can relapse our disease when they do eventually divide. During a short 3-day fast, apparently - if the science reported above is correct, blood stem cells (including leukemic stem cells) are induced to divide in order to replenish the blood supply - at that time, circulating TKI will attack the Leukemic stem cell during division and kill it. I might just have to try this .... 3 It does seem fasting is counter-intuitive, but the research is compelling.)

Fascinating Scuba.  Is there a specific protocol for fasting or do you just not eat period for three days?

I have fasted on an off for years doing a one day fast only. As we are in Lent (and I gave up all alcohol (#@@#)@$%#) , I am going to try a three day fast as described in the article (and other articles I have reading).

My plan in the next few weeks is to have a final Sunday dinner and then not eat on Monday, Tuesday and Wednesday. I'll resume with a light breakfast (break - fast) Thursday morning. I will drink only water, tea (Earl Grey from Harrods!) and probably coffee. I will continue to take Sprycel (20 mg) and Curcumin during this time. I will also test that my body went into Ketosis using Ketone strips. The key is knowing my body has entered ketosis. This usually takes (from what I have read) anywhere from one to three days. If you exercise, sooner, if not, later during the three day period.

When I start, I'll report here. The science is compelling. If, during the three days, my bone marrow LSC population comes out of quiescence and begins dividing, both the Sprcel and lack of glucose should kill off many of this population. Should that occur, my next cessation attempt might very well succeed! At least that is the theory. Only a true random clinical based trial would show this works. But why wait.

And losing a few pounds won't hurt either. This is going to be tough..

Additional info:

Hi Scuba I always pass on your recommendations to my husband but he would kill me if I suggested this one :) After having no appetite initially , he is really hungry these days and he goes off to work with a huge pack lunch and needs dinner as soon as he gets home. All healthy foods but def in big quantities. 

I can’t wait to hear how it goes and thanks for being our guinea pig! 


Scuba do you ever check out the LLS site? I feel some people  posting there would benefit from your expertise .....

This would not work for those of us on imatinib because we must take it with food; do you agree?

You don't have to take imatinib with food, but lots and lots of people find that it makes them queasy if they don't. I know I felt decidedly squiffy if I took imatinib on an empty stomach.

The package insert says: "Gleevec is sometimes associated with GI irritation. Gleevec should be taken with food and a large glass of water to minimize this problem."

I think fasting would be very difficult if you are taking imatinib. During the first clinical trials they were not sure if IM should be taken with a meal so it was suggested that we take it with a 'light' meal..... for me that caused terrible nausea and vomiting - not a good experience at all. Later it was shown that food did not affect the absorption of IM so I always took it with my main meal of the day.


Sandy - That is a very good point! When I first took Gleevec - if I did not take enough food with it, the nausea was terrible.

Gleevec is out then for a three day fast. My theory relies on leukemic stem cells being coaxed into dividing (main purpose of fast), but then a TKI would have to be circulating when that happens so that they (stem cells) can be attacked.

Only when they are dividing are leukemic stem cells susceptible to a tyrosine kinase inhibitor.

Hi Scuba,

I must admit the whole concept of fasting to starve cancer cells is absolutely radical and out of convention!

In fact, it appears to contradict just about everything i've ever read and learned on dietary health for cancer patients undergoing chemo. That being said, i'm a bieliever in stories with two opposing sides, so I'm definitely grateful to have this one in the bag for future reference!

Personally being on nilotinib for my CML, i have to palm off this one because fasting can further aggravate/ elevate the blood bilirubin level.

So, just a quick word of caution to anyone on this forum currently on Tasigna, please make sure to instigate a full history check of your respective bilirubin levels before attempting any fasting regimen.

High level of blood bilirubin/ bile acid concentration can promote injury to the liver. Trust me, liver damage is the last thing we need while on a TKI agent.

Scuba, although i'm sitting the bench with this one, I'm still keen to hear all about your venture, so please keep us posted on your progress.

Best Regards,

Hi Ellie,

I read your note with interest regarding fasting and Bilirubin.

I came across two articles for additional insight:

The second reference is noteworthy in suggesting that fasting affects Bilirubin in males, but not females. I was only able to read the abstract so no reason was put forth.

Regarding fasting and cancer - I also was surprised at the correlation. I read several papers by Dr. Longo and his data was compelling. On reflection, his results are no longer counter intuitive.

Our bodies were not designed through evolution to eat all of the time. Natural periods of no food followed by feasting was the norm for our ancestors. It is probably a reason why we put on fat during times of plenty so easily. With that in mind, higher than normal bilirubin levels during a fast is shown to be helpful in providing an anti-oxidant environment for clearing out recycled blood cell waste (mostly red cells).  During a fast, the body scavenges and repairs. As long as bilirubin is excreted normally (via bile), a temporary higher than normal bilirubin level is tolerated (and may even be helpful). I checked my own bilirubin level from last test and I had a low normal level. My low rbc count is probably the reason (mild anemia due to Sprycel suppression).

As the fast period is short (3 days), I suspect that any short term increase in bilirubin won't be an issue.

I remain intrigued with the idea that a 3 day fast may coax leukemic stem cells (LSC) out of quiescence and lead to their destruction by my TKI. The idea is compelling enough that I will try this.

I will let this forum know when I start and finish.

Thanks Scuba for your response and additional information on bilirubin.

On the whole, I couldn't agree more with your reference to early human's daily food intakes since aeon ago. And to some extent i even agree that fasting can be good for healthy bodies and those who are not already at an increased risk of exacerbating side effects of a medication such as hyperbilirubinemia and nilotinib in treatment of ph+ leukemias.

On the general health news front, an article did claimed that intermittent fasting is good for body and mind recommended mainly for men, but not for some women due to insulin reduction-related issue. Well, that alone can't be great news for some women on this forum who are already struggling with abnormal blood glucose. Hence, once subtracted variables such as cancer, chemo and TKIs from the equation, one question remain: is fasting really for everybody?

Let's not forget about the clinical standpoint which observed and confirmed an existing correlation between elevated bilirubin and nilotinib therapy. On that subject, one prominent article penned by Aichberger et al. (American Journal of Hematology, 2011) observed that one of the most frequent laboratory abnormalities seen with nilotinib-treated arm is hyperbilirubinemia amongst other changes to the liver enzymes.

Personally, my own experience with nilotinib, fasting and bilirubin resulted in similiar outcome.

Here's my brief encounter with hyperbilirubinemia; approximately a month and half ago, i had to have a glucose fasting test done to screen for diabetes mellitus as nilotinib is known to promote this disease morbidity.

The required fasting period for my glucose study was 8hrs prior to blood test which eventuated closer to 14hrs in the end. During this mandatory fasting, i kept to my normal nilotinib dose regimen and down only water leading to the appointed date/time of said test. On top of glucose study my hemotologist also ordered other blood chemistry studies for the month.

Suffice to say that the following afternoon on the next day, i received a call from my hemotologist telling me that the bilirubin in my latest blood results is too high - 76umol/L to be exact. Way too high, were his words. And at the time he asked for my symptoms and possibly if i had any dietary change that may have contributed to the spike increase in the bilirubin count. Of course, i shared his overall concerns because historically since the start of treatment my bilirubin level was consistent between 22umol/L - 25umol/L, higher than normal but acceptable within the clinical setting (normal range: <20umol/L).

Another point to note from my experience is this, even after more than a month and half since the fasting test, my bilirubin level still hasn't fully returned to what it once was. And to my latest blood test it persisted above 40umol/L.

Hence, needless to say, being on nilotinib treatment alone already predisposed a person (as was the case with me) to higher bilirubin level during fasting compare with the general population regardless of gender.

Again, to anyone on this forum currently undergoing the nilotinib/ Tasigna therapy, please ensue to either instigate your own bilirubin level check or consult your treating physician prior to attempting any fasting regimen.

Best Regards,

This is a fascinating thread. I too am on Tasigna and experienced slightly elevated bilirubin and ALT about 2 months into treatment.  These levels spontaneously returned to normal in about 4 - 6 weeks.  During this time I was on full dose (600 mg/day) Tasigna.  I am currently on low dose (150 mg/day) and have had all normal CBC and metabolic results for almost a year now. 

Re: fasting, I have never tried the 3 day regimen that Scuba is going to try, but for decades, I have followed an eating schedule where I have my first meal around noon, second around 6 PM and then a nightime snack at 10.  Thus, I fast intermittently for 14 hours each and every day.  I have seen some mention of this in the literature as intermittent fasting and some suggestion that this might also have a beneficial impact.  I know it didn't stop me from getting CML, but I wonder if it has had anything to do with my rapid response to Tasigna (MMR in less than 90 days, PCRU in 10 months - all while reducing dose from 600 to 150 mg/day). Anyway, just wondering what Scuba and others think about this form of daily fasting versus the 3-day regime, particularly as it relates to Tasigna and elevated liver results and whether a fasting period of 14 hours per day has any impact on those hard to find mutated stem cells of ours.

Ellie - your link to an article highlighting the different response to fasting (vis a vis bilirubin) between men and women is noteworthy. Fasting is not for everyone for the reasons you listed. An additional thought I do have is whether 3 days is sufficient to bring permanent harm to the body (female in particular) in exchange for the potential wipe-out of leukemic stem cells? Is the risk worth it?

In my case, the decision is easy because my bilirugin is low to begin with and I don't have any diabetes signs, but for others (especially when a 3 day fast and LSC destruction is only a theory) any decision along these lines to fast should be guided by your thoughtful suggestions.

As an aside - I do wonder how we might have evolved along gender lines where men are better able to tolerate a fast than women (as per your linked article). Perhaps the hunter / gatherer evolution where males typically left the "home" to go find food and could be gone for days and women stayed behind to mind the family where food is kept more or less constant. The males would have to endure the hunt and maintain their blood sugar levels with little or no food. Those that couldn't - didn't pass their genes on to the next generation. I do know that on long car trips with my wife - no way can she go long hours without food available (low sugar) while I am tempted to just keep driving until the gasoline runs out. It's all very interesting.

I haven't started my 3 day fast yet. Too many goodies in the pantry to deplete first.


CMLJAX - It could certainly be possible eh? We're largely guessing based on a 'hint' that fasting causes a high blood system turnover. The facts we know is that a 3 day fast does reset the immune system ( by causing blood cells (red as well as white) to be scavenged by the body for recycling. This in turn up-regulates key enzymes which triggers bone marrow blood production to replace lost cells. These are facts we do know from Dr. Longo's research. Where I make the leap (not-scientific, but reasoned) is that if the bone marrow is triggered to replace blood - then stem cells are needed to come out of quiescence to jump start the process. My question is do blood stem cells (leukemic as well as normal) come out of quiescence, in fact,  and begin dividing. Further - if they do start to divide, are they then vulnerable to a tyrosine kinase inhibitor (such as Sprycel, Tasigna, et. al.) during division which would kill them? My theory is that It seems they would. We do know that it is the dividing leukemic cells which die due to TKI's (binds to the ATP energy site needed for cell division). LSC's escape death when they are non-dividing, which can last for years and can relapse CML when TKI's are withdrawn.

I am excited to try this concept - and losing a few pounds are a bonus. I'll let everyone know when I start and then I intend to stop taking Sprycel six months later and see if I can hold my PCRU.

As an aside - giving a pint of blood should have the same effect - yes? Any relatively sudden drop in blood amount should trigger the blood system to re-generate. Of course, we are not allowed to give blood as we have CML, but it is nevertheless intriguing.

Hi Cmljax,

Well done on your achievement of the golden milestone and success in your CML treatment. And in such a short span of time! It is nothing short of amazing to see others found a TKI that work so well for them relative to response rate/ tolerability framework.

On the topic of fasting and nilotinib, thank you for your input and share of experience on the subject.

To your comment on whether fasting has played a vital role in your successive response rate; well, i guess you may never really know the truth.

But what i do know is this; nilotinib is 30-fold more potent then imatinib but lost to dasatinib which carry a massive 300-fold potency over the first generation TKI in treatment of ph+ leukemias.

In my particular case i choose to believe that nilotinib did all the hard yard in my rapid response rate.

That is, 6 months into treatment with Tasigna, I went from borderline accelerated phase at diagnosis/ start of treatment to reaching MMR. Subsequently, my PCR was 0.032% in Dec 2017, my 12month time point.

Currently, i'm on the standard dose; 600 daily.

I guess the main point I'm trying to make here is; the response profile of nilotinib in and of itself is well documented to rapidly induces molecular remission in chronic phase in as early as 3 months into therapy. So, without knowing your PCR % at your diagnosis, i can imagine a similar response trend has occurred in your treatment, fasting aside.

Then again, it might just be what you have speculated - that concurrent Tasigna regimen and intermittent fasting may've helped with your exponential response rates in such a short time. It is a shame that we can never know that for a fact.

All the same, I'm keen to see the picture Scuba's experimental fasting will paint for us all to see and learn from. Thus, i hope to hear more from him on the subject to fully conclude the fingings on whether fasting is beneficial in CML.

Best Regards,

Scuba, though i don't claim to fully understand the functioning roles of cavemen and their wives relative to food supply management and cavekeeping, i did laughed aloud upon hearing about your wife and her habitual food fixes! Indeed, I can totally relate with your missus in that i used to snack regularly and especially on interstate business trips, i would often packed more snacks in my suitcase than clothes! On that note, i doubt anyone can really blame me, given the shocking portion and taste often met with airline food. Bleh. However, treatment with nilotinib changed my entire outlook on food and dietary health. Safe to say, I now eat to live rather than live to eat! Yes, boohoo to me...

Back on the subject of fasting, once you have depleted your goodies supply and ready to commence fasting, i hope to hear all about your progress!

Best Regards,

Surprise - I started, but I don't think I am going to make it three days.

Yesterday morning, I was so busy that I went most of the day without eating. Around 4:00 p.m. when I would normally have a glass of wine and some Gouda cheese, I thought why not now. I gave up all alcohol for Lent (which each year after Lent I swear I'll never give up again) and decided to not eat. I drank some tea and kept drinking water instead through the evening.

I went to bed hungry and used the feeling to think about those who are forced to go without food not by choice.

Today is day two. No hunger, but a definite energy low. I have a meeting later in the day with some intense intelligent people and I will be curious if my mind will be sharp enough to engage.  And there will be plenty of food around. That will be my test. If I can get past that - I will have two days of no food under my belt (which I am hoping will also get more loose!). And then Friday ...

One day is fairly easy - the next two are going to be tough and that is when the benefit is supposedly achieved. I will probably do some light exercise to accelerate the glycogen depletion. It is only after all glycogen (i.e. sugar) is gone from the Liver that hormones are released which begins the cellular recycling. I continue to take my 20 mg Sprycel dose.

On the morning of the fourth day when I will resume eating, it is food which causes the liver to signal the bone marrow to make more blood cells triggering stem cell division (that is the theory). So on Saturday morning, I will take Sprycel at the same time as breakfast. It is my hope (non-scientific, but an experiment nonetheless) that dividing leukemic stem cells (LSC), being forced out of quiescence, are bombarded with circulating Sprycel and killed. Only when LSC's are dividing are they susceptible to TKI attack. I won't know the result until I stop Sprycel after my next PCR test.

In March, I will have gone nine months PCRU. The protocol for stopping is two years. Instead, I will stop in June at the one year mark and test whether my PCR becomes positive. It will take another six months to a year of PCRU without any drug before I could claim success. We will never know if it was due to my 3 day fast experiment. Only a properly designed clinical trial can do that. But, I sure would suggest to other CML patients to give it a go.  The fasting research shows that immune system turnover is greatly accelerated by a 3-day fast (Dr. Longa's work). We also know that blood stem cells divide to re-supply the blood once food is re-introduced. What we don't know is whether the presence of a TKI during this replenishment phase is sufficient to kill either all LSC's or kill enough of them to reduce the critical level needed to restart CML. I'm just guessing on all of this, but I'm hoping the logic is compelling. There is no risk in trying and only overcome.



At diagnosis, my PCR was 43%, WBC was 28,800 and platelets were 648, so I was in early chronic phase with no symptoms at all. I reduced my dose fairly rapidly due to a number of rare and uncommon side effects that my oncologist as first refused to associate with the Tasigna.  Absent these side effects, he would not have agreed to even the first dose reduction, let alone the next 2. I have to tell you that both Scuba and Sandy Craine provided the inspiration and justification for dose reduction giving me the courage to fight for this. And it was a bit of a fight at first.  I still have a few mild, intermittent side effects on 150 mg/day, but the difference is night and day.

Given where you started, your response is excellent. You have reached a PCR level where you should begin discussing dose reduction with your doc. These TKI's are wonderful drugs and we are very fortunate to have them, but they are also toxic, so we should find the lowest dose possible that allows is to maintain response at MMR or below.  More and more docs are beginning to manage CML in this way, but it is not yet official protocol, so many allow dose reduction only in response to bad side effects (e.g. your bilirubin).  Good luck and continued good progress.

Scuba, how is the fasting going? Thinking about trying this too, but suppose to take my Bosulif with food. Maybe a cracker or two wouldn’t hurt?

Hi Melanie,

Well... I made it two days! I am till in Ketosis (buning fat), but on the third day, I was feeling "weird" with heart palpitations. So I decided to have a light soup, avocado and a piece of cheese and carrots. Within 15 minutes of eating my heart settled down. Not enough carbs to stop the Ketosis effect, but not the full program as documented by Dr. Longo. I do feel I may have done some good as he reports autophagy (blood cell recycling) begins to happen once the body goes into Ketosis and that was a day or so before I stopped. Once I started to eat, I made sure I took Sprycel because eating again is suppose to trigger stem cell division.

I will have to try this again, but next time I will prepare an electrolyte drink (magnesium, potassium, sodium, etc.) so I don't get those heart palpitations again. That is what I think happened.

What you might try is eating food that has fat in it instead of crackers to go with your Bosulif such as Gouda cheese or an avocado. As a result of my reading on fasting and Dr. Longo's work, I will no longer eat crackers out of a box. Too many processed carbs.

This is what CML has done to me. Ruined my love of pizza, beer, bread and pasta!


Thanks for the update and great information. I think you did great!

Still thinking on the wisdom of trying a fast when not PCRU and already low wbc. I’m a bit concerned about the regeneration or the stimulation of cell division if I’m still carrying a burden of leukemia cells. Might this stimulate the leukemia cells also?

My husband is willing to fast with me so that would be great support. I could easily take my Bosulif with avocado or Gouda, but would that really be fasting? Maybe I’ll just have to do 24 hours, although I doubt that wouldn’t get me to the Ketosis effect. I Really like the idea of giveing my marrow a restart! 

In my old age, I’ve become far less disciplined and don’t think I’ll ever be able to deny myself some of my favorite foods, like breads and pastas. Moderation is the best I can do!

There is a growing body of science now regarding fasting and health.

The link above is but one example.

The cells that are "stimulated" are the stem cells - both normal (HSC) and leukemic (LSC). Both are typically quiescent. They only divide when there is a sudden need for replenishment of the progenitor cells (as during a sudden blood loss or trauma or major infection). The science behind fasting shows how the body uses existing old blood cells for protein and other building blocks to keep the body going while looking for food. We have a lot of extra blood (which is why we can donate a pint of it from time to time). The blood acts as an additional reserve for the body. This apparently is triggered when glycogen is depleted and the body begins to burn fat for energy.

The truly interesting part occurs when the fasted person begins to eat again. At that time, the body goes into rebuild mode and the stem cells divide to re-generate the immune system (blood system overall). Having a TKI present when this occurs is how the LSC's get attacked. Only when they divide are they susceptible to a TKI.. So "stimulating" the leukemic stem cell is what we want to do. To sort of get them out of hiding so they can be destroyed.

As a practitioner of fasting, or at least a occasional faster.
When I got sick I looked into the cancer fasting thing,

The idea of fasting and cancer was explored during early chemo
cancer affect days. It was theorized that normal cells would start to
close down when food was restricted and cancer cells would
continue to be voracious and gobble up all extra food in sight.
When chemo laced food, (glucose), with poison (chemo),
the cancer cells would get a higher dose of chemo then usual, and
the healthy cell would get a smaller dose then they would if they were
eating normal amounts.
This worked but only on certain cancer/chemo treatments and worked modestly.
It is used as I understand patient specific.

I have a cousin that has brain cancer and they wrote her off ten years ago,
and she went on a serious fast and nutrition regime and she is alive today and doing well.
She still has that tumor in her brain as it’s inoperable and calcified.
She don’t look real good but you wouldn’t know she has cancer.
It’s been ten years. She talks a mile a minuet....She’s seventy.

CML stem cells are not dependent on TKI., but if you keep messing up their
sand castle you just might wear them out before their time. Work them to an early
death. Make them work harder and maybe they will die sooner.

TKI's make Leukemia stem cells work harder.

I don’t know if it works. But I do it. and I am PCRU.
Personally I think the drugs work better without food to dilute it
It’s like drinking wine on an empty stomach. It seems to work better.
The medicine will dictate the option of fasting.

To fast or not to fast, that is the question.
Whether it’s nobler in the mind to fast
And suffer the slings and arrows of hunger pains
Or take a cheeseburger and an order of fries
and piss the whole thing.

a little English reference



You're so funny.

Thanks for being here.


a fellow traveler into the murky waters of CML.