Severe Calorie Restriction: Helpful with Cancer Treatments?
by Mila McManus, MD
A recent clinical trial suggests that short-term, severe calorie restriction (called a fasting-mimicking diet) results in biological effects that may be helpful in cancer treatment. Cancer Discovery, the American Association for Cancer Research journal, published the report.
Severe, short-term calorie restriction activates the immune response and is also safe and inexpensive. Combined with standard anti-cancer therapies, the biological impacts included a decrease in blood glucose, insulin, and growth factor. In addition, there was a reduction in peripheral blood immunosuppressive cells and enhanced T-cell populations, which can identify and target tumor cells. The severe calorie restriction generated a metabolic “shock” that activated immune cells, boosting other cancer treatments’ antitumor activity.
The fasting-mimicking diet consisted of a five-day severe calorie restriction. The diet was a low-carbohydrate, low-protein, plant-derived diet. Patients were given up to 600 calories on the first day, and up to 300 calories were given on days 2, 3, 4, and 5. The total calories consumed over the five days was up to 1800. Patients repeated the cycle every three or four weeks for up to eight weeks. Between fasting cycles, there was a refeeding period of 16-23 days, during which patients were not restricted but guided to adhere to a healthy diet and lifestyle.
One of the most valuable findings for the severe calorie restriction diet was that patients did not experience progressive weight loss common to cancer patients. Rather, the patients were able to maintain weight. Additionally, the diet is tolerated by the majority of patients, with fatigue being the most common side effect.
We do not recommend severe calorie restriction or fasting-mimicking diets without consulting your medical provider first. This may not be the best protocol for every situation, and you should ask your medical provider if it is right for you.
Be well.
References: