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.
The research clearly indicates that there is a benefit to fasting, yet you say the research is wrong because of the opinions of several oncologists.
I'm biased because several oncologists told me something that wasn't true.