The neutropenic diet and its impacts on clinical, nutritional, and lifestyle outcomes for people with cancer: a scoping review.

The neutropenic diet (ND) is often recommended to people with cancer to reduce infection risk despite recommendations of clinical guidelines advising against its use. While recent literature suggests the ND does not reduce infection risk, other outcomes related to health, nutrition, and lifestyle are unknown. The aim of this review is to systematically scope the literature on the ND in people with cancer for all outcomes related to clinical health, nutrition, and lifestyle. Scientific databases were systematically searched. Eligible studies were in English, people with any cancer type, consuming an ND, any age group, date, or setting. Eligible study types were randomised control trials, observational studies, systematic reviews, and meta-analyses. Twenty-one studies met the inclusion criteria. Outcomes of interest found were infection rates, fever, mortality, antibiotic use, gastrointestinal side effects, comorbidities, biochemistry, hospitalisation, nutritional status, quality of life (QoL), well-being, and financial costs. Most research has focused on infection and mortality rates with few assessing hospitalisation rates, nutritional status, financial costs, and QoL. Most included studies found no significant differences between ND and comparator diet for mortality, antibiotics use, comorbidities, and QoL; however, several studies reported the ND significantly increased the risk of infection. Gaps in the literature included effect of ND on QoL in an adult population, microbiome, lifestyle changes, and financial burden. Further research is needed regarding how the ND affects the microbiome and QoL of its consumers, but in the interim, it is important for hospitals providing an ND to their patients to liberalise the ND wherever possible.