• Posted December 9, 2024

High-Fiber Diet May Prevent a Blood Cancer in People at High Risk

People who have a condition putting them at high risk for a bone marrow cancer may be able to ward off the malignancy with a high-fiber diet, new research shows.

The study focuses on patients with what's known as monoclonal gammopathy of undetermined significance (MGUS). It's a bone marrow abnormality that's often a precursor to multiple myeloma, one of the most common forms of blood cancer.

The small study -- just 20 MGUS patients -- found that a change of diet that boosts fiber intake may slow or prevent the onset of multiple myeloma.

That makes sense, the research team said, since prior studies have suggested that poorer, meat-rich diets put folks at higher risk for the cancer.

The new findings "support how we as physicians can empower patients, especially those with precancerous conditions, with knowledge on reducing their cancer risk through dietary changes," said study lead author Dr. Urvi Shah. She's a myeloma specialist at Memorial Sloan Kettering Cancer Center in New York City.

Her team presented its findings Saturday in San Diego at the annual meeting of the American Society of Hematology (ASH).

The new study involved patients with MGUS who were also overweight or obese. As the researchers noted, obesity is also a risk factor hiking the odds that MGUS will progress to full-blown cancer.

For 12 weeks, participants switched to a plant-based diet that was high in fiber. They also got six months of dietary coaching.

Patients were allowed to eat as much as they wanted as long as they stuck to the diet, which was rich in fruits, vegetables, beans, seeds and whole grains.

Participants lost an average of 8% of their starting body weight after 12 weeks on the diet. They also showed improvements in insulin resistance (a marker for diabetes), their gut's microbiome and their overall quality of life, the researchers said.

All of this was linked to a slowdown in MGUS progression.

Two of the patients whose MGUS was already showing signs of progressing to cancer saw a "a significant improvement of their disease progression trajectory," according to a Sloan Kettering news release. None of the patients had progressed to multiple myeloma by one year after enrolling in the trial.

Shah's team note that prior studies in mice had already found that 44% of myeloma-prone mice fed a high-fiber diet did not progress to the disease, while another group of mice that ate normally all developed the cancer.

"This study showcases the power of nutrition -- specifically a high fiber, plant-based diet -- and unlocks a better understanding of how it can lead to improvements in the microbiome and metabolism to build a stronger immune system" that might help ward off myeloma, Shah said.

She said that a larger study, this time involving 150 MGUS patients, is planned.

Because these findings were presented at a medical meeting, they should be considered preliminary until published in a peer-reviewed journal.

More information

Find out more about multiple myeloma at the Leukemia & Lymphoma Society.

SOURCE: Memorial Sloan Kettering Cancer Center, Dec. 7. 2024