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Fasting and Cancer (additional information)

There has been increased interest in fasting and cancer lately. And people reaching out to me inquiring about my experience.

Allistair's earlier post had a link to a video where "experts" were asked about it and they reacted negatively without information and cautioned people that it's not advised. There are other experts, however, who are discovering there might be something to fasting and cancer.

There is emerging science regarding how fasting works to alter gene expression in the body and effecting immune response (favorable) against cancer.

The experts in the video were unaware of this new information:

Any time an "expert" claims to know something and render an opinion without actual experience or knowledge is doing a disservice to their patients. They should just say they don't know. Being cautious is fine. And doctors run liability risk if they venture outside established protocols. That is why I seek out researchers in the field on the leading edge not doctors who practice. Medical researchers learn first leading to establishing a new protocol before the general medical professional knows about it (such as treatment free remission - established. Lowering dose to manage side effects with increased response - established. Combining TKI's in certain cases for effective treatment - established).

On this forum, we get exposed to lots of ideas from our members where we scour for new information constantly. In many ways "we" are on the leading edge before our own doctors know about it. Caution is always advised when trying something new before it is established protocol. But following doctors advice blindly can be dangerous too.

I believe fasting has a chance at eradicating my CML stem cells. I believe that trying it is of little risk (downside: it may simply not work). I believe that if it doesn't work, I will still lose a few pounds, improve my glucose and metabolic profile, clean out old dead cells and be better for it anyway. In other words fasting is good for you as it has been practiced in religions around the world for thousands and thousands of years. I decided to apply a 3 day fasting regime twice a year aimed squarely at impacting my bone marrow to coax stem cell division - that's the theory based on experimental evidence. My personal experiment is that during re-population of blood cells that occur at the end of the fast my TKI (dasatnib) will attack the leukemic stem cell division and destroy them. Fasting impact on CML is my hypothesis. There is no evidence this will work. It seems reasonable to me to try. I will never know if it truly worked because I am already PCRU and when I stop dasatinib to test treatment free remission I may just remain CML free anyway. All I am doing is an attempt to increase the odds in my favor.

And lose a few pounds in the process!

Perhaps we'll see a clinical trial* where this approach is tested scientifically (rather than anecdotally as I am doing). But clinical trials need money - and there is no money to be made testing fasting. This is where a government funded trial can be of benefit.

(*There are a few clinical trials underway looking at fasting and cancer, but none looking at CML.)

I actually tried a very strickt keto diet and it doesn’t seem to have effect on my cml.

I was diagnosed 1.5 years ago, i’m in MR4.5 now, and taking 100mg dasatinib. I’m 33 years old with no other health issues besides CML, so i didn’t really have to worry about any adverse sideeffects.

I started my diet with a 3 day water fast, and then followed with a carb restricted (>10g) and calorie restricted (>1500cal) diet. 

I was trying to follow the keto diet protocol described in Thomas N. Seyfried’s book: Cancer as a Metabolic Disease. I bought a blood glucose monitor to try to keep my blood sugar levels within the therapeutic range, which proven to be extremely challenging. 

I’m following the diet for more than 2 months now, and i will keep going.



- I lost a lot of weight which is a great success on its own... -10kg so far. Started at 103kg, today 93kg. 

- My BCR-ABL remained at MR4.5, in fact it actually increased slightly from 0.0019 to 0.0031, but i have these fluctuations so i wasn’t concerned. Given that my private insurance is covering all my tests i can do them quite often, so I did a qpcr in mid Dec and mid Jan, and i’ll do another one at the end of Feb.

- I had some very mild side effects from sprycel, some headaches, some minor skin rashes, and the most annoying one pimples on my face. The diet seem to be improving all of these. But frankly none of the side effects were serious to start with, more like a nuisance. 

I came across an article the other day that was talking about the ketogenic diet research for various (mass) tumors. To adjust your expectations they phrase their findings very carefully, like “decrease the tumor burden” after testing mices for 6+ months... so is this going to be a cure? - i doubt. But surely it will make you a healthier person. Will you be happier? Na-ah... it is very hard. I watched many youtube videos about the keto diet before i started, and all of theese fitness gurus are claiming how much energy they have. Cow poop. I’m continuously tired. Not hungry, true. But tired. 

Anyway... loosing weight was my primary goal, and for that this diet was great. I will keep going, and let you know if there are changes in my results, for your future reference. 

Thomas - Great to read your personal experience with this approach.

Of course you know there is no difference between 0.0019 and 0.0031 PCR .... Anything below 0.01% is indistinguishable from PCRU - but it's a number that shows an upward line - I get it. 

My fasting test is to see if a 'series' of 3 day fasts (3 per year) over a two year period will keep me in treatment free remission. My last attempt failed before I learned about fasting and its impact on blood rejuvenation. So this is an odds increasing idea. Not scientific - just anecdotal. And the weight loss alone made it worth it along with great metabolic numbers.

Hi Scuba,

3 days might not be enough. In Dr Seyfried’s book recommend to start with 7 days if you are coming off from a regular “american diet”. Even that is just a broad guess. As the book explains the goal is to force your body into autophagy, and that will happen once all your sugar reresves depleeted, which really depends on how much carbs you’re eating ordinarily. 

I started with a 3 day waterfast which didn’t drive my body into ketosis (i was overweight... 103kg for my 182cm), so likely the autophagy didn’t start either. The raging ketosis kicked in about one week after my 3 day fast (1 week without eating any carbs)... thats how long it took to depleete my body’s sugar reserves.

I suggest to you to measure your blood or urine ketone levels, just to make sure you are not pointlessly torturing yourself. Good luck!


I use ketone sticks to measure ketone levels. I enter ketosis after a day fasting. I will remain in ketosis after starting food again as long as my carb load is less than 20-30 grams. In any given month I spend most of it in mild ketosis.

I follow Dr. Valter Longo's research regarding fasting. In his work, 3 days is sufficient for most "normal" weight people to achieve autophagy. I can definitely see the benefit of longer fasts for overweight people. By following 3 days - the so-called fasting risks are minimal (minimal to me = zero).

Any time the body is deprived of food and excess carbs are burned, the body enters autophagy. The act of losing "fat weight" (i.e. not water water/carb weight) puts the body into autophagy as long as there is no protein ingest. Just a little bit of the amino acid leucine will end autophagy instantly. Zero food for as little as 18 hours following carb depletion accelerates autophagy dramatically - and triggers stem cell activation (the reason I do fasts in the first place) upon re-feeding. Keep in mind what's happening. The body ALWAYS has sugar flowing - even during a fast. It has to or we die. This is the minimal amount needed for life support. The body makes its own sugar from protein + glycerol (fat). Autophagy provides the protein parts (instead of muscle) for this synthesis. So the body, in effect, is cleaning house getting bits of protein where it can to keep glucose levels at minimum levels (around 70 ng/ml). The body does not need much sugar when burning ketones for major fuel needs. Just a little bit of protein and fat and the body can go on like this for a long time. Once re-feeding occurs - almost immediately autophagy stops.

My approach is to cycle my body periodically through a series of shorter 3 day fasts several times a year to cycle this process. My goal is to rid myself of CML. For all I know it's already gone because I am PCRU, but only treatment free cessation will test this for me and even then, it won't be conclusive (i.e. scientific). I'm following a hunch. There will likely never be a clinical trial to test this idea. No money to be made. But there is benefit in trying anyway - lose a few pounds, clean up the body's interior and maybe - just maybe - end CML.