The first randomized prospective clinical evaluation of the effects of fasting on chemotherapy (the “incidence of chemotherapy-induced nausea and vomiting in cancer patients”) was published in 2014, but the patients were dogs. Cancer-bearing dogs presenting at a veterinary hospital were randomized to be fasted for 24 hours before chemotherapy, and those that were were significantly less likely to suffer from vomiting—only 1 in 10 compared to 2 out of 3 in the nonfasted group, which is great.

But what can that tell us about human medicine? Evidently, not much. It is nearly impossible to rely on most animal data to predict whether or not an intervention will have a favourable clinical benefit-risk ratio in human subjects.

For example, mice have a metabolic rate approximately seven times higher than humans, so a single day of fasting can cut lean body mass by about 15 per cent. That would take over a month of fasting in people. So that dramatic study on mice showing 100 per cent alive versus 100 per cent dead on high-dose chemo depending on whether they fasted for 60 hours? What can that really tell us?

When it comes to cancer, rodents can bear massive tumour loads, whereas people generally waste away and die when tumour masses have reached just a thousandth of our body weight. You can’t even necessarily extrapolate from one rat to another, even within the same strain bought from different dealers.

Guaranteed findings

The only way to see what happens in humans, the only way to guarantee findings are relevant, is to study people. The theory is that combining fasting cycles with chemotherapy could extend the survival of advanced-stage cancer patients by both retarding tumour progression and reducing side effects––or even providing an alternative to chemotherapy altogether for early-stage cancer patients. But that’s all contingent on being confirmed in human clinical trials.

First, there was a case series. Several patients diagnosed with a wide variety of cancers elected to undertake fasting prior to chemotherapy and share their experiences. Those who underwent chemo, both with or without fasting, reported a reduction in fatigue, weakness, and gastrointestinal side effects while fasting; in fact, they felt better across the board, with zero vomiting in the fasting group. The weight lost during the few days of fasting was rapidly recovered in most of the patients and did not lead to any detectable harm, so overall, it looked feasible and safe, with the potential to ameliorate side effects.

But only randomized clinical studies could tell for sure, and so here we go. Breast and ovarian cancer patients fasting, starting 36 hours before and ending 24 hours after chemotherapy, did appear to improve quality of life and fatigue, but another study found no such beneficial effects. There did appear to perhaps be less bone marrow toxicity, given the higher counts of red blood cells and platelet-making cells. But no benefit when it came to killing off white blood cells—the immune system cells—so that was a disappointment. Perhaps they didn’t last long enough? They only fasted 24 hours before and after.

To find out the optimal duration, 20 cancer patients were split up into three groups, fasting for 24, 48, or a total of 72 hours. All those in the 24-hour group suffered nausea after chemo, but less than half in the 72-hour group, and most were vomiting in the 24-hour group, but none in the longest fasting group. Longer fasting groups also tended to suffer less nerve damage and less serious bone marrow suppression. Even after 24 hours of fasting, two cycles of chemo can knock people’s white blood cells down to suboptimal levels. But within 72 hours, chemo knocked their immune system down but not out.

Okay, so short-term fasting may reduce chemotherapy-induced toxicity. But what I want to know is if it makes it work better. A systematic review of 22 studies found that, overall, fasting was found to not only reduce chemotherapy side effects (like organ damage, immune suppression, and chemotherapy-induced death) but also to suppress tumour progression, including tumour growth and metastasis, resulting in improved survival. But… nearly all of the studies were on lab animals.

The studies on humans are limited to evaluating safety and side effects. The tumour-suppression effects of fasting, for example, its influence on tumor growth, metastasis and prognosis, have not been evaluated – until now.

Stage 3 regression

In 2015, a remarkable case report was published in which a woman with stage three follicular lymphoma underwent a medically supervised, 21-day water-only fast, after which her enlarged lymph nodes were substantially reduced in size. The patient then remained on a whole food, plant-based diet, and at six and nine-month follow-up visits, she remained asymptomatic.

In 2018, her three-year follow-up was published. Remarkably, she appeared to remain cancer-free, confirmed by CT and PET scans. Her cancer appeared to have been knocked down and out. The initial regression persisted for three years with no additional intervention other than the dietary change.

Could it have just been a coincidence? Sure, but the initial regression directly coincided with the timing of her water-only fast, suggesting a causal relationship, and there are biological mechanisms by which fasting may potentiate tumour regression, such as decreasing levels of insulin-like growth factor 1 (IGF-1).

The term “spontaneous regression” of cancer is a misnomer. Obviously, there was something that caused the regression, whether or not we know what it is. Presumably, the immune system plays a role. The fact that you can get a marked increase in cancer rates when you are immunosuppressed suggests that cancers are popping up all the time, but your immune system is normally able to keep them at bay.

There was an example, for instance, of a regression after a transfusion of blood from a patient who had previously sustained a spontaneous regression; or cases of patients who had been free of metastases for 15 or 20 years, only to develop rapidly fatal metastases after some type of stress or shock that apparently sharply reduced their resistance.

For most cancers, spontaneous regression is exceedingly rare, but lymphoma is an exception. Of 140 cases of nodular lymphoma (which is what they used to call follicular lymphoma), there were 18 cases of at least partial and 6 cases of complete regression. So, 1 in 25 cases just go away on their own. But, when you have follicular lymphoma cases in which tumours shrink after any kind of treatment—in this case, after some herbal supplement—you always have to ask: is this cause-and-effect or just coincidence?

Elevated natural killing activity may be one of the possible mechanisms responsible for spontaneous regression of malignant lymphoma. Natural killer cells may be part of our first line of defence against cancer by destroying tumour cells. And if you compare the natural killer cell activity of those with malignant lymphoma that spontaneously regressed, versus those whose cancer didn’t, or a control group, the spontaneous regression group does seem to be on the high end.

How can we increase natural killer cell activity naturally? Exercise can do it, unless, apparently, you’re eating a high-fat diet. Those randomized to undergo an exercise training program on a high-fat diet actually suffered a decline in natural killer cell activity, suggesting training on a high-fat diet is detrimental to the immune system.

Eating lots of contaminated fatty fish may also adversely affect natural killer cell levels. But put people on a low-fat diet, and you can dramatically increase natural killer cell activity within a matter of months by about 50 per cent, suggesting that dietary fat might increase the formation of cancer by depressing the tumour surveillance capacity of the immune system.

The bottom line in terms of fasting is that, at present, long-term fasting in cancer treatment is supported only by some case reports; so, more research is desperately needed. Sadly, there is currently no clinical research evaluating the effects of water-only fasting and a whole food plant-based diet on follicular lymphoma in humans.

Long-term fasting is certainly not without risk. In one case, a guy opted to try a 60-day fast instead of chemotherapy for non-Hodgkin lymphoma. He ended up hospitalized in a coma and respiratory failure because of Wernicke encephalopathy, a life-threatening neurological emergency caused by thiamine deficiency. But starting on a healthier diet seems like a win-win, no-brainer. Just putting people on plant-based, whole foods, sugar-oil-salt-free diet, with or without fasting, is sometimes sufficient to induce an intense healing response.

NOTE: This article was republished under Creative Commons License