Relationship between food behavior and taste and smell alterations in cancer patients undergoing chemotherapy: A structured review

Introduction: Taste and smell alteration is a frequent side effect of chemotherapy. However, little is known about their influence on patients' food behavior and the mechanisms underpinning their occurrence. This lack of clarity is likely due to a series of factors among which heterogeneity in chemotherapy-induced taste and smell modifications may play a prominent role. The present review provides a critical overview of the evidence on the association between taste and smell alterations and food behavior modifications in cancer patients undergoing chemotherapy.

Design: The literature search was performed using PubMed and Google Scholar databases and restricted to literature for English-language articles published between 1990 and June 2018. Sensory-related terms were combined with food behavior-related terms to identify the studies that examined the association between these two terms. The retrieved studies were grouped based on the taste and smell assessment outcomes.

Results: Thirteen eligible articles were included in the review. The studies varied in design, length, methodology of assessment, and studied population. The categorization of studies depending on taste and smell assessment outcomes allowed the definition of three patient profiles: unaltered, hypo- and hyperchemosensation (taste and/or smell). Alterations were significantly correlated with patients' energy intake and macronutrient preferences suggesting that sensitivity of each patient to olfactory and gustatory stimuli is likely to play a role in food behavior modulation during cancer and chemotherapy.

Conclusion: The review summarizes and provides relevant associations between taste/smell alterations and food behavior while receiving chemotherapy considering existing individual variations. Given the sensory influence on food behavior modulation, a better characterization of smell and taste alterations before the launch of chemotherapy seems important for a better understanding and management of patients' food behavior trajectory over the treatment.