Physician Assistant UTSouthwestern Simmons Comprehensive Cancer Center Dallas, Texas, United States
BACKGROUND Nearly 48% of patients with cancer actively seek health benefits from special diets as a way to improve disease outcomes (Zick et al., 2018). Intermittent fasting has increased in popularity among patients with cancer as an adjunct to chemotherapy. Intermittent fasting encompasses a wide spectrum of dietary patterns involving episodes of calorie restriction or calorie reduction over a set period of time. However, limited research is available examining the feasibility, safety, tolerability, and treatment effect of intermittent fasting during chemotherapy.
OBJECTIVE · Evaluate the evidence of fasting on patients with cancer undergoing systemic therapy · Identify limitations in the research to provide oncology advanced practitioners (AP) with evidence-based information to guide clinical decision making
METHODS A comprehensive literature search was conducted using Ovid MEDLINE®, Ovid Excerpta Medica Database (EMBASE®), and the Cumulative Index to Nursing and Allied Health Literature (CINAHL®) databases. The search utilized a combination of Medical Subject Heading (MeSH) terms and keywords for various spellings and/or terminology related to cancer, fasting, and chemotherapy while following the Population, Intervention, Comparison, Outcome (PICO) framework (Brown, 2020). A systematic approach was used to identify and screen research studies following the Preferred Reporting Items for Systemic Reviews and Meta-Analyses (PRISMA) guidelines (Page et al., 2021). Five hundred and fourteen articles were identified from the three databases. Seven studies remained after applying inclusion and exclusion criteria: three randomized control trials, one randomized crossover trial, one controlled crossover trial, and two prospective cohort studies.
RESULTS The seven articles identified for final review examined four outcomes essential to understanding how fasting impacts patients with cancer and cancer treatment: fasting compliance, malnutrition, therapy side effects, and cancer outcomes. Data suggests overall good compliance, no malnutrition, minimal side effects, and mixed results for cancer outcomes. Limitations of the seven studies included small sample size, bias toward gender, race, and cancer type, interventions involving only normal weight patients with body mass index (BMI) > 18 kg/m2, variation in fasting protocols, and short-term follow-up surveillance.
CONCLUSION Intermittent fasting as adjunct to chemotherapy in normal weight patients with cancer has the potential to be a feasible, safe, and tolerable nutritional intervention. However, these findings are less generalizable to the greater oncology patient population given the limitations identified among the current available literature. There is not enough evidence to support intermittent fasting as a nutritional intervention to improve disease or treatment outcomes.
RECOMMENDATIONS Large-scale randomized controlled trials are needed to validate the current findings and determine what future role intermittent fasting may play in cancer management. Oncology APs should use caution when considering the use of intermittent fasting in adjunct to chemotherapy.
