Things We Do For No Reason: Neutropenic Diet
For several decades, providers have routinely restricted the diets of neutropenic cancer patients by eliminating foods that might harbor pathogenic microbes to reduce infection rates. These diets, known as neutropenic or low-bacteria diets, are prescribed across the country with little uniformity in the extent or content of prescription. These diets are difficult to follow and force patients to omit fresh fruits and vegetables and limit dairy and meat products from their diet. These dietary omissions compromise nutritional intake in patients who are already at high risk of malnutrition. Randomized trials have shown that these restrictive diets are not superior in preventing infections than more liberalized diets. Evidence shows that adherence to the Safe Food-Handling guidelines issued by the Food and Drug Administration, a mandate for all hospital kitchens, provides adequate protection against food-borne infection, precluding the need for the neutropenic diet. Thus, routine use of the neutropenic diet should be abandoned.
© 2018 Society of Hospital Medicine
The “Things We Do for No Reason” series reviews practices which have become common parts of hospital care but which may provide little value to our patients. Practices reviewed in the TWDFR series do not represent “black and white” conclusions or clinical practice standards, but are meant as a starting place for research and active discussions among hospitalists and patients. We invite you to be part of that discussion. https://www.choosingwisely.org/
CLINICAL SCENARIO
A 67-year-old man with acute myeloid leukemia who has recently completed a cycle of consolidation chemotherapy presents to the emergency room with fatigue and bruising. He is found to have pancytopenia due to chemotherapy. His absolute neutrophil count (ANC) is 380/mm3,and he has no symptoms or signs of infection. He is admitted for transfusion support and asks for a dinner tray. The provider reflexively prescribes a neutropenic diet.
BACKGROUND
Although aggressive chemotherapy regimens have significantly improved survival rates in patients with cancer, these intensive regimens put patients at risk for a number of complications, including severe, prolonged neutropenia. Patients with neutropenia, particularly those with ANC< 500/mm3, are at a significantly increased risk for infection. Common sites of infection include the blood stream, skin, lungs, urinary tract, and, particularly, the gastrointestinal tract.1 Oncologists
The neutropenic diet is a national phenomenon. A survey of 156 United States members of the Association of Community Cancer Centers revealed that 120 (78%) of the members had placed patients with neutropenia on restricted diets.2 The triggers for prescription (neutropenia, or starting chemotherapy), ANC threshold for prescription, and duration of prescription (throughout chemotherapy or just when neutropenic) were not uniform. A majority of centers restricted fresh fruits, fresh vegetables, and raw eggs, while some locations also restricted tap water, herbs and spices, and alcoholic beverages.2 Similarly, a study of practices in 29 countries across 6 continents found that 88% of centers have some version of a neutropenic diet guideline with significant heterogeneity in their prescription and content. For example, dried fruits were unrestricted in 23% of centers but were forbidden in 43%.3
WHY YOU MIGHT THINK THE NEUTROPENIC DIET IS HELPFUL IN PREVENTING INFECTION
The rationale behind the neutropenic diet is to limit the bacterial load delivered to the gut. Studies have shown that organisms such as Enterobacter, Pseudomonas, and Klebsiella have been isolated from food, particularly fruits and vegetables.4,5 The ingestion of contaminated food products may serve as a source of pathogenic bacteria, which may cause potentially life-threatening infections. Mucositis, a common complication among cancer patients receiving therapy, predisposes patients to infection by disrupting the mucosal barrier, allowing bacteria to translocate from the gut to the bloodstream. Given that neutropenia and mucositis often occur simultaneously, these patients are at an increased risk of infections.6 Cooking destroys bacteria if present, rendering cooked foods safe. Thus, the avoidance of fresh fruits and vegetables and other foods considered to have high bacterial loads should theoretically decrease the risk of infections in these patients.
WHY THE NEUTROPENIC DIET IS NOT HELPFUL IN PREVENTING INFECTION
Researchers have investigated the ability of the neutropenic diet to reduce infection in adult and pediatric neutropenic patients. A study involving 153 patients receiving chemotherapy for acute myeloid leukemia or myelodysplastic syndrome randomized 78 patients to a diet that restricted raw fruits and vegetables and 75 patients to a diet that included those foods.8 The groups had similar rates of major infection (29% in the cooked group versus 35% in the raw group, P = .60) with no difference in mortality.7 In a randomized, multiinstitutional trial of 150 pediatric oncology patients, 77 patients received a neutropenic diet plus a diet based on the food safety guidelines approved by the Food and Drug Administration (FDA), while 73 children received a diet based on FDA-approved food safety guidelines.8 Infection rates between the groups were not significantly different (35% vs 33% respectively, P = .78).
