Intermittent fasting and its impact on toxicities, symptoms and quality of life in patients on active cancer treatment

Intermittent fasting is a dietary intervention that is increasingly being tested for positive outcomes in patients receiving cancer treatment. In this review, we examine the impact of intermittent fasting on symptoms, toxicities, and quality of life in patients undergoing cancer therapy and highlight unmet investigative areas to prompt future research. While current evidence is preliminary and conclusions mixed, some promising clinical studies suggest that intermittent fasting interventions may improve fatigue and reduce gastrointestinal toxicities in certain patients with cancer. Emerging clinical evidence also demonstrates that intermittent fasting may reduce off-target DNA damage, and induce favorable cellular-level immune remodeling. Furthermore, intermittent fasting has the potential to lower hyperglycemia and the ratio of fat to lean body mass, which may benefit patients at risk of hyperglycemia and weight-related adverse effects of some common pharmacological cancer treatments. Larger controlled studies are necessary to evaluate intermittent fasting in relation to these endpoints and determine the effectiveness of intermittent fasting as an adjunct intervention during cancer care. Future cancer trials should evaluate intermittent fasting diets in the context of multimodal diet, exercise, and nutrition strategies, and also evaluate the impact of intermittent fasting on other important areas such as the circadian system and the gut microbiome.