Intermittent Fasting for Cancer Patients
Intermittent fasting is a style of eating with a few different variations that are all based on cycling through periods of fasting and eating normally. This kind of eating is most often used to boost weight loss, for which it has been proven effective. However, there are a number of additional health benefits from brain health to heart health, to protection against diabetes.
For patients with mesothelioma or another type of cancer, the benefits of intermittent fasting are hopeful. There is evidence from research that fasting in any form could slow tumor growth, boost the immune system, reduce treatment side effects, increase survival rates, and prevent recurrences. Research is ongoing, but for now, as long as done with medical guidance, intermittent fasting is safe and beneficial for cancer patients.
What is Intermittent Fasting?
Intermittent fasting refers to any one of a few different strategies of cycles of alternating eating and refraining from eating, or fasting. It isn’t really a diet, although some people use it to lose weight, because it does not indicate what kinds of foods you should eat. It is really more a pattern or style of eating that according to research has some real health benefits, including potentially helping cancer patients. Some of the different types of intermittent fasting include:
- 24-Hour Fasting. This type of fasting means not eating at all for 24 hours. So, for example someone practicing this may choose to not eat between dinner one day and dinner the next day. This is typically done once or twice a week.
- The 5:2 Diet. The 5:2 strategy modifies 24-hour fasting. It involves restricting calories for two 24-hour periods per week. On those two days women eat 500 calories and men 600.
- The 16/8 Fast. Most popular for people using intermittent fasting to lose weight, this strategy involves not eating for 16 hours every day. Most people do this by skipping breakfast, for example, and not eating between 8:00 at night and noon the next day.
- Calorie Restriction. This type of diet isn’t exactly fasting because there are no designated periods of not eating. But it is similar because it reduces overall calories. Calorie restriction involves reducing daily calorie intake by 20 to 40 percent every day for an extended period of time. A general guideline is 1,200 calories per day for women and 1,400 for men.
Health Benefits of Intermittent Fasting
There are significant changes that occur in the body during fasting: human growth hormone levels increase, insulin levels drop, cell repair processes speed up, and there are changes to gene expression. These changes, and potentially others, are being used to explain some of the surprising health benefits that are seen with all types of intermittent fasting and calorie restriction.
The benefit that most people turn to intermittent fasting for is weight loss. It is proven to promote weight loss and especially fat loss. This is due to lowered calorie intake, but goes beyond that with hormone changes that promote fat loss. Intermittent fasting also increases metabolic rate, making the body burn more calories.
Research is proving that there are many benefits to this style of eating that go well beyond weight loss. It lowers blood sugar levels and helps to reduce resistance to insulin, both of which protect against diabetes. Fasting is also proven to improve cardiovascular health and to promote nerve cell growth in the brain, possibly protecting against degenerative brain diseases like Alzheimer’s. In laboratory animals, intermittent fasting has been shown to slow the aging process and extend life. For cancer patients, there may be even more exciting and hopeful benefits of practicing intermittent fasting.
Triggering the Immune System for Cancer Patients
One way in which a fasting diet may help cancer patients is by triggering the immune system. The immune system is designed to target and destroy pathogens in the body, like viruses. However, it seems to be less able to find, target, and kill the body’s own abnormal cells, like cancer cells. A lot of new cancer treatments are being developed to stimulate the immune system to do this, but new research is finding that a simple fasting diet could also do it.
Once recent study from the University of Southern California was conducted using lab mice and found that when the mice received chemotherapy and a fasted diet, the immune system was better able to target and kill breast cancer cells and skin cancer cells. The mice produced more immune system cells when on the fasted diet, including the B cells and T cells that actively target and kill tumor cells. Another discovery was that cells that normally protect tumors—called T regulatory cells—were kept out of the tumors. This may have helped chemotherapy drugs work better.
The same researchers also conducted a pilot study with human cancer patients, mainly to determine if fasting diets with chemotherapy would be safe. Both a water-only, two-day fast and a four-day, restricted-calorie diet that mimics fasting were found to be safe for cancer patients under the supervision of doctors. All of these findings indicate that fasting or a fasting-mimicked diet along with chemotherapy could be used to slow tumor growth in cancer patients.
Reducing Cancer Recurrence and Mortality Rates
Other studies have used intermittent fasting with cancer survivors to determine the effects. In one study, survivors of breast cancer practiced intermittent fasting by going for 13 hours per day without eating, a modification of the 16/8 fast. The results were reductions in cancer recurrence in the fasting group, by 36 percent. The fasting group also had better survival rates. Adding two hours to the fasting time gave even better results.
Fasting May Reduce Cancer Treatment Side Effects
Cancer treatments, especially chemotherapy, can cause side effects in patients that range from uncomfortable to debilitating. Studies have found that intermittent fasting can protect against these side effects. In one study, cancer patients fasted for a few days and then ate a normal diet before treatment. They did not lose a dangerous amount of weight or see any interference with the cancer treatments.
They did, however, see benefits in reduced side effects as compared to patients who did not fast. Patients who participated in the fasting diet experienced less fatigue and weakness, fewer headaches, less nausea, and no vomiting. They also saw reductions compared to the control group in dry mouth, mouth sores, cramps, and numbness.
Risks of Intermittent Fasting
Some critics of this style of eating worry that it promotes unhealthy eating patterns and even eating disorders. There may be a slight risk that someone will binge eat between fasting periods, for instance, which is not recommended and may reverse the beneficial effects of the diet. There are also concerns that some people may use fasting for health benefits but end up losing unhealthy amounts of weight, leading to malnourishment.
The research, however, does not support the concerns. Multiple studies have determined that intermittent fasting, when guided by doctors or other medical professionals, is safe. It is important to note that fasting and long-term calorie restriction can potentially be unsafe. Practicing any style of fasted eating should be done under the guidance of doctors, especially for people who are ill or have cancer.
Intermittent fasting may sound like a chore, but most people report that it is not difficult to do and that they feel better for it. If you are living with mesothelioma or another type of cancer, it may be worth giving a fasting diet a try. Just be sure to talk to your medical team and your oncologist before doing it and practice intermittent fasting only with medical guidance.
Page edited by Dave Foster
Dave has been a mesothelioma Patient Advocate for over 10 years. He consistently attends all major national and international mesothelioma meetings. In doing so, he is able to stay on top of the latest treatments, clinical trials, and research results. He also personally meets with mesothelioma patients and their families and connects them with the best medical specialists and legal representatives available.Connect with Patient Advocate Dave Foster