Modulation of response to cancer chemotherapeutic agents by diet constituents: is the available evidence sufficiently robust for rational advice for patients?

Background: Patients who are diagnosed with cancer want advice on how they may alter their diet or which diet supplements they should take to augment chemotherapy. Methods: We conducted a review of the literature mostly from the last 15 years on the interaction between dietary constituents and antineoplastic therapy in preclinical rodent models and in clinical trials. Results: Studies have explored the effect of predominantly antioxidant vitamins and folate on efficacy or toxicity mediated by cisplatin and anthracyclins. Cisplatin toxicity in rodents was ameliorated by vitamin E. The design of clinical studies of dietary agents in combination with cytotoxic agents has been very heterogeneous and results have been inconclusive. Conclusions: Whilst preclinical experiments hint at a potential benefit of certain dietary agents, the evidence emanating from clinical studies does not allow firm conclusions to be made. Future studies should explore physiological doses of dietary agent and include pharmacokinetic and pharmacodynamic measurements.