Dietary influences on symptomatic and non-symptomatic toxicities during cancer treatment: A narrative review

The general nutritional status of cancer patients could be a central determinant of cancer treatment-related toxicity and an indicator of cancer symptoms such as cancer-related cachexia and weight loss. This narrative scientific review covers the impact of dietary patterns (for example, Mediterranean diet, short-term fasting, ketogenic diet), dietary components (for example, fruits and vegetables, fish oils, turmeric/curcumin, dietary fiber, phytochemicals, vitamin/mineral dietary supplements), and the gut microbiota on symptoms, toxicities, and adverse events associated with cancer treatment. Although several studies have produced controversial or inconclusive results, some promising preclinical studies and initial clinical trials suggest that dietary interventions may alleviate certain cancer treatment-related symptoms and toxicities. Possible mechanisms by which dietary components may influence symptomatic and non-symptomatic toxicities during cancer treatment include through impacting inflammation, oxidative stress, muscle mass, cardiac health and regulating the gut microbiome. Current ongoing studies will continue to shed light on whether specific dietary interventions, with a special emphasis on the gut microbiota, are an effective method to improve cancer treatment outcomes. Future studies should examine the synergistic effects of combining different nutritional interventions and establish diet-related guidelines for cancer treatment.