Neutropenic diet and quality of food: a critical analysis

The use of low microbial diets for immune-suppressed patients is controversial (1). Low microbial diets are intended to reduce the ingestion of bacterial and fungal contaminants by the exclusion of uncooked fruits and vegetables, undercooked eggs and meat, un-sterilized water, un-pasteurized dairy products (2). In this issue of the Revista Brasileira de Hematologia e Hemoterapia, Galati et al. report on an investigation of the microbiological profile and vitamin C content of raw and cooked foods destined for neutropenic patients (3). The use of a low microbial diet or neutropenic diet after hematopoietic stem cell transplantation (HSCT) was instituted more than 30 years ago as a means of preventing infection from organisms colonizing the gastrointestinal tract. Evidence supporting this practice is lacking however, and the actual efficacy of neutropenic diets remains unknown (1,4). Some argue that insufficient research and the high cost of these diets is enough reason not to implement them. Thus, the policy of some institutions has discontinued their use, such as in the Northwestern Memorial Hospital in Chicago, which stopped the practice of neutropenic diets in 2006 (4). Nevertheless, others argue that despite lack of clinical evidence, it is prudent to be cautious and continue to provide immune-suppressed patients with low microbial diets (1,2,4) , which implies, in turn, higher dietary restrictions. A recent study followed patients admitted to a high-efficiency particulate air-filtered room (protected environment) receiving induction therapy for newly diagnosed acute myeloid leukemia (AML). They were randomly assigned to a diet containing no raw fruits or vegetables (cooked diet) or to a diet containing fresh fruit and fresh vegetables (raw diet). The rates of major infection and death, the two major end points of the study, were similar regardless of whether patients were on the cooked or raw diet (5). A retrospective study of 726 consecutive HSCT recipients studied 363 who received a neutropenic diet and 363 who received a general hospital diet in order to determine the incidence of microbiologically confirmed infections during and after transplantation. The study demonstrated a higher rate of infections in the HSCT recipients who received the neutropenic diet (6). Although there is an international trend in not maintaining severe dietary restrictions for immunosuppressed patients, including HSCT, a Brazilian study carried out recently showed that there are still differences among professionals concerning which foods are allowed, especially during the critical period of immunosuppression (CPI) (7). In the international literature several foods, …