Foods Cancer Patients Don't Like Revisited |STAT

The neutropenic diet, in which almost all food is cooked at a high temperature to reduce the risk of infection, has been reduced in the treatment of cancer.A new study could change that.

Oncologists have abandoned the notoriously unpopular neutropenic diet, which almost all requires cooking at high temperatures. Or, as some have described it, "boiled to death," to reduce the risk of foodborne illness, but evidence in recent years shows that eating them doesn't actually protect against infection. So doctors are beginning to abandon the strict neutropenic diet.

Now, a new study published last week in the Journal of Clinical Oncology is giving some doctors pause on fresh fruits and vegetables for patients whose treatment involves severe suppression of the immune system, particularly neutrophils, the white blood cells that are key to warding off infection.Contrary to previous studies, the trial found that blood cancer patients who were allowed a less restrictive or liberalized diet had 11% more infections than patients who preferred a neutropenic diet.

Talal Hilal, a cardiologist and bone marrow transplant physician at the Mayo Clinic, said: "There has been a movement in the last 10 years to provide nutrition for patients. But in reading the paper, Hilal said, "it raises the question of whether we can rethink how we want to be with our patients."

Oncologists began using a neutropenic diet several decades ago, especially for cancer patients undergoing intensive treatment, such as those undergoing hematopoietic stem cell or bone marrow transplants.This procedure can give certain blood cancer patients a chance to recover, but sometimes with chemotherapy doses that are very hard on the immune system.

A weakened immune system recovers after the procedure, making infections more likely to become fatal until the patient's cell count recovers.Hospitals go to great lengths to protect these patients, including preventing outside food or fresh flowers from entering their rooms.Doctors assured them they were better than introducing dangerous bacteria, viruses, or fungal spores to the defenseless.

However, over the years, evidence has shown that normal diets do not cause infection risk.Instead, neutropenic diets were blamed for reducing patients' quality of life and increasing malnutrition.Therefore, hospitals have gradually returned to being more flexible with neutropenic patients.

Notably, in 2023, a group from the University of Milan published the first randomized evidence that for some stem cell transplant patients, an unrestricted diet is no worse than a neutropenic diet, leading many oncologists to rejoice that the benefits of a neutropenic diet have finally been disproven.An unrestricted diet has also been shown to improve quality of life.

But John Wingard, a hematologist-oncologist and professor at the University of Florida, wanted to look again.In particular, he wanted to know whether the lack of dietary restrictions for neutropenic patients could improve the nutritional quality of patients, an ongoing challenge for many patients with cancer.Like the Milan group, Wingard enrolled more than 200 blood cancer patients and distributed them to receive a comfort diet of fresh fruits, vegetables, and chronic yogurt or a neutropenic diet.In this study, patients were allowed to eat at home or restaurant food as long as dietary guidelines were followed.

Wingard planned to look at how many clinically confirmed infections each group had over different time periods."The data safety monitoring committee forced us to stop the study prematurely because the liberalized diet had 11 percent more infections," Wingard said.Wingard added that only half of the patients who were allowed a generous diet ate fresh fruits or vegetables."When we analyzed only people following a liberal diet, the infection rate was 1.5 times higher."

Studies have also suggested that allowing simple diets does not improve nutrition or quality of life for patients.

Together, the Mayo Clinic's Hilal says it is beginning to reconsider more practices and diets for transplant patients."It seems to me that if you are liberalizing the diet and you do not see an improvement in quality of life or nutritional status, there is no trade-off. Why should I be comfortable with liberalizing my diet if I do not benefit in any other area?"he said.

There are some caveats, Hilal said.First, the patient populations in both the 2023 Milan cohort study and this study are different.The 2023 paper was a multicenter study that may help eliminate hospital-specific bias. It was also done in Europe, where some practices are similar to those in the US."They are also a high-risk population that seems to be written into this JCO document," he said.

Ultimately, Hilal said, he feels the study will reignite the debate about the neutropenic diet, and cancer researchers will likely discuss the strengths and weaknesses of both tests.

Notably, Hilal and other doctors, including Wingard, said it is probably still reasonable to allow a non-restrictive diet with other patients such as solid tumor patients who may still be neutropenic, but not as high risk or neutropenic for as long as bone marrow transplant patients.This study also showed that prolonged neutropenia was the main variable associated with infection.No patients died during the study intervention either, and oncologists are very good at dealing with infections.

As for why the diet doesn't improve patients' nutrition or quality of life, Wingard suggests that patients with advanced cancer treatment may feel nauseous, lack appetite and generally feel uncomfortable.Regardless of what food is available, some patients struggle to eat.

"I don't think the neutropenic diet is that bad," Wingard said."Patients who have been treated this way have symptoms called dysgeusia, which means that everything doesn't taste right. Then you get nausea and stuff."

Wingard said perhaps the best way to resolve the neutropenic diet debate and help patients' quality of life and nutrition is to focus on improving treatment.New, effective treatments that are less toxic to the immune system may mean that something like a neutropenic diet is no longer needed.