Controversy exists around the recommended diet for neutropenic oncology patients. Despite compelling evidence, many patients are placed on restrictive diets, which can range from a few restrictions to elimination of entire food groups such as avoiding all fresh fruits and vegetables. To make matters more confusing, patients may hear different diet recommendations from various providers and clinics, leaving them unsure about what is “safe” to eat. To provide insight on this topic, we asked Kerry McMillen, MS, RD, CSO, clinical supervisor of Medical Nutrition Therapy at Seattle Cancer Care Alliance (SCCA) to provide an evidenced-based view of the diet recommendations for neutropenic patients.
While several studies have examined the role of diet and infectious risk, the protective benefit of a “low microbial”, “low bacterial” or “neutropenic” diet against infection in hematopoietic transplant (HCT) patients has not been established. Despite this, a survey by Smith and Besser, involving 156 institutions belonging to the Association of Community Cancer Centers, reported that most centers still utilize some type of neutropenic diet for their HCT population.
Depending on the degree of restriction per institutional “neutropenic diet” guidelines, diet variety is compromised, which can limit food palatability, ability to meet macronutrient needs and has the potential to impact the ability to maintain the gut microbiome. With increasing numbers of patients receiving their transplant in an out-patient vs an in-patient setting due to the advent of nonmyeloablative and reduced-intensity allogeneic transplant regimens, it is important that patients receive appropriate education during their transplant course to balance optimizing their nutrition status and diet variety with minimizing foodborne illness.
At the Seattle Cancer Care Alliance, HCT patients do not follow a neutropenic diet. Instead, they follow an “immunosuppressed diet”, which allows well-washed whole fruits/vegetables, yogurt, kefir and other sources of dietary fiber as well as pre- and probiotics. Patients are instructed to follow the immunosuppressed diet when their absolute neutrophil count is <1000mm3, and/or with start of conditioning as well as for the duration of time on immunosuppressive medications when patients remain at high risk for infection. A recent study validated the safety of this diet approach. A total of 12 out of 4,069 (0.3%) allogeneic and autologous HCT patients from 2001-2011 developed a bacterial foodborne infection within 1 year after transplantation at the SCCA. Other study results also question to rationale for strict “neutropenic diet” precautions such as the recent study by Trifilio, that looked at >700 HCT patients and found that a neutropenic diet did not prevent infection and, in fact, had a greater number of infections than patients on a general hospital diet.
Because oral feedings are indicated for patients with a functional GI tract, it is essential to maximize food choices for HCT patients. There is clearly need for additional research to determine how to balance infectious risk vs diet variety, but the trend appears to be moving in the direction to liberalize vs restrict food choices.
Kerry McMillen, MS, RD, CSO is the Clinical Supervisor for the Medical Nutrition Therapy department at the Seattle Cancer Care Alliance in Seattle, WA. She has worked with the HCT population for the past seventeen years.