This information is dangerously wrong. I have asked several oncologists specifically about fasting during chemotherapy and they all recommended strongly against it.
Your understanding of how chemotherapy works with cancer and healthy cells seems flawed. Chemo harms all fast-growing cells, healthy or not. That’s why people have terrible tastes, stomach problems, hair and skin problems during chemo; those are all fast-growing cells. They grow fast whether you are fasting or not; but killing them in large numbers (what the chemo does) raises the body’s demand for energy and nutrients just to maintain health. That demand must be met with healthy food and drink.
Edit to add: Fasting by a healthy person may reduce their chances of developing cancer; that seems plausible to me. My point is that people undergoing chemotherapy should follow the directions of the doctors. In my experience, those directions are to eat well while receiving treatment.
After having researched this topic some, I decided to fast prior to my chemotherapy infusions. I cannot comment on its effectiveness as I haven't experienced chemotherapy without fasting, nor long fasts without chemotherapy. I haven't experienced nausea, but have encountered most of the other expected side effects. Maybe their severity is lessened, but I wouldn't know. In any case, it's been thus far endurable. I haven't decided if I'll continue or try not fasting. (Based on the information I found, I've been fasting for a total of ~2.5 days before each 2-week infusion cycle begins and then another ~2.5 days after the first infusion day.)
I only found preclinical studies. And anecdotal results from others who have tried it. I've been unable to find any good evidence that the efficacy of the chemotherapy is enhanced, only that side effects can be mitigated.
Two oncologists I've seen are not supportive of my fasting but haven't strenuously objected to my decision either.
FWIW, a third oncologist opposed my undergoing chemotherapy at all. I've found, in general, a lack of consensus as to proper treatment, at least in my situation. I've now consulted with seven specialists (four oncologists and three surgeons) and the recommendations haven't been consistent. And most of them decline to give definitive directions, leaving the major decisions to me. My point being that, at least in some situations, following the directions of doctors isn't necessarily an option.
> Abundant and convincing preclinical evidence shows that STF can decrease toxicity and simultaneously increase efficacy of a wide variety of chemotherapeutic agents.
> For general cancer prevention, it may be beneficial to add intermittent or short-term fasts in combination with a plant-based cancer prevention diet
and
>Fasting may also protect patients against the harmful side effects of chemotherapy or radiation therapy.
and
> They concluded that a 3-day fast could help regenerate a strong immune system
> Additional research in both rodents and monkeys have shown that when CR was started by 12 months of age, lifespan was increased and incidence of spontaneous cancers was reduced by 50%.
> Furthermore, it is theorized that cancer cells do not respond to the protective signals generated by fasting, thus leaving them vulnerable to both the immune system and cancer treatment.
I feel like this is sufficient to refute your several oncologists' anecdotal opinions which are not supported by the research.
> There is a growing body of evidence supporting the role of fasting in both cancer treatment and prevention.
Lots of links to sources in that article too.
You have to be very careful relying on the advice of oncologists. Think about what their motivations are. What are their biases? I dealt with this very personally for a long time and found oncologists to be ... human and suffer from all the same problems as other humans.
Their patients are ... dying and they don't want to die. It's a very emotional time for all involved.
There's an impressive body of research on this subject already, it's just unfortunate that many (most?) oncologists haven't caught up yet with the science.
A common objection is that chemotherapy causes weight loss, and it's important that patients keep their weight up. Where this argument falls down, is when you look at why chemo patients lose weight - and it's primarily due to the treatment reducing their appetite.
So if you're then able to reduce side effects of chemo (which it appears fasting does), patients are then more easily able to eat and maintain/recover their weight.
> I feel like this is sufficient to refute your several oncologists' anecdotal opinions which are not supported by the research.
It's not. Unless you have the appropriate training and experience, you are not capable of making treatment recommendations.
Sorry if that seems harsh, but this is not something you can just Google your way through. This is not one of those things where you can find the hidden truth by reading a few things online and posting citations.
You either have medical training or you don't. If you don't, be very careful about make big medical decisions based on a few things you read online. Plenty of people apply the same heuristic to decide that vaccines are bad, homeopathy works, you can treat cancer with an all-fruit diet, etc.
> You have to be very careful relying on the advice of oncologists. Think about what their motivations are. What are their biases?
Think about what your motivations and biases might be. You're human too.
Medical research is an inductive endeavor; avoiding deductive fallacies won't help you much.
You have to distinguish between these two statements:
a) There is research that indicates that there is a benefit to fasting
b) The research indicates that there is a benefit to fasting
Statement a) is true; but b) is what you said.
Going from a) to b) is the hard part. It's not enough to know what some research says, you need to place it within the broader context of the field of knowledge before you can make declarative statements of benefit. And cancer is an incredibly complex and fast-moving field of knowledge.
The oncologists I spoke with were aware of research into voluntary fasting, but on balance recommended against it. One reason is that unlike with a healthy person, ending the fast may not be under the patient's control, depending on how they tolerate their chemotherapy. Chemotherapy ends up looking like intermittent fasting for a lot of patients anyway.
Chemotherapy is also cumulative, which means that decisions that appear beneficial in early rounds may end up limiting the total number of sequential rounds that a patient can tolerate.
If someone is not habitually fasting, adding it on top of chemotherapy adds a significant confounding factor to a process that is already hard to predict.
And aside from voluntary fasting, there is a lot of evidence that patients who can eat well and keep their weight up have better outcomes from chemotherapy than those who can't/won't eat and lose weight.
This is what I was told by people who spend their lives studying the treatment of cancer.
> One reason is that unlike with a healthy person, ending the fast may not be under the patient's control, depending on how they tolerate their chemotherapy. Chemotherapy ends up looking like intermittent fasting for a lot of patients anyway.
It sounds like you are saying that the right answer depends on an individual's circumstances. I would agree. Certainly fasting could be harmful for some people depending upon their overall medical situation.
> If someone is not habitually fasting, adding it on top of chemotherapy adds a significant confounding factor to a process that is already hard to predict.
For my situation, the clinical evidence I could find suggested that chemotherapy does not have a statistically significant impact on the probability of disease-free survival. Even the oncologists who are recommending chemotherapy have been reluctant to claim it would necessarily be beneficial. This increased my interest in adding the significant confounding factor of fasting. In fact, you could say that I've been actively seeking significant confounding factors as the default path is rather dark.
As you noted, cancer is an incredibly complex and fast-moving field of knowledge. Given the currently limited research into the impact of fasting, I decided to conclude that maybe it can be helpful (especially since the biological hypotheses made some sense to my primitively educated mind).
Returning to your earlier point, I'm not sure it's currently possible to make a blanket claim of fasting being good or bad with respect to its impact on cancer patients. It seems that it would depend upon the patient's individual situation and priorities.
I agree that each course of treatment depends on each patient's individual situation and priorities. And I absolutely believe that each patient has the right to decide their own treatment when facing such a serious diagnosis.
What I object to is someone without medical training reading a few articles online and then posting universal declarations that fasting is good for everyone on chemo, and that people shouldn't trust oncologists for some reason. Obviously that's not you.
I made a statement derived from lots of research I have personally done. You said I was wrong. I provided evidence of the research. You provided ... none.
You said I was "dangerously wrong" because someone else you talked to said I was wrong, but you have provided no evidence supporting your case, other than hearsay.
I have provided evidence. You concluded with:
> This is what I was told by people who spend their lives studying the treatment of cancer.
Which, again, is appeal to authority. It's a logical fallacy.
> Current data in humans suggests that IF may be beneficial for chemotherapy outcomes, particularly for reducing toxicities. IF appears to be safe in appropriately selected patients, and the adverse effects associated with fasting appear to all be of low grade.
> Growing preclinical evidence shows that short-term fasting (STF) protects from toxicity while enhancing the efficacy of a variety of chemotherapeutic agents in the treatment of various tumour types. STF reinforces stress resistance of healthy cells, while tumor cells become even more sensitive to toxins, perhaps through shortage of nutrients to satisfy their needs in the context of high proliferation rates and/or loss of flexibility to respond to extreme circumstances.
Your understanding of how chemotherapy works with cancer and healthy cells seems flawed. Chemo harms all fast-growing cells, healthy or not. That’s why people have terrible tastes, stomach problems, hair and skin problems during chemo; those are all fast-growing cells. They grow fast whether you are fasting or not; but killing them in large numbers (what the chemo does) raises the body’s demand for energy and nutrients just to maintain health. That demand must be met with healthy food and drink.
Edit to add: Fasting by a healthy person may reduce their chances of developing cancer; that seems plausible to me. My point is that people undergoing chemotherapy should follow the directions of the doctors. In my experience, those directions are to eat well while receiving treatment.