New research showcases the potential of plant-based diets in the prevention of multiple myeloma and gastrointestinal cancers.
Several new studies highlight the significant impact of dietary choices on cancer progression and prevention, particularly concerning multiple myeloma and gastrointestinal (GI) cancers. The first, a recent clinical trial conducted by Memorial Sloan Kettering Cancer Center (MSK), demonstrated that a high-fiber, plant-based diet may delay the progression of precursor conditions to multiple myeloma. Concurrently, research from Flinders University emphasized that diets rich in fruits, vegetables, whole grains, fish, legumes, and dairy can reduce the risk of GI cancers.
Multiple myeloma, the second most common blood cancer, often develops from precursor conditions such as monoclonal gammopathy of undetermined significance (MGUS) and smoldering multiple myeloma (SMM). Individuals with poor diet quality and reduced intake of plant-based foods have an increased risk of progressing to multiple myeloma. Additionally, those with elevated body mass index (BMI) are twice as likely to progress to multiple myeloma compared to individuals with normal BMI.
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In the MSK study, 20 participants with MGUS or SMM and elevated BMI underwent a 12-week high-fiber, plant-based dietary intervention, followed by 24 weeks of health coaching. The diet emphasized whole plant-based foods, including fruits, vegetables, nuts, seeds, whole grains, and legumes. Participants experienced significant improvements in quality of life, insulin resistance, gut microbiome health, and inflammation. On average, participants lost eight percent of their body weight after 12 weeks. Notably, one year after enrollment, none of the participants had progressed to multiple myeloma.
Urvi Shah, MD, MSK myeloma specialist and lead of the Nutrivention study, presented these findings at the 2024 American Society of Hematology annual meeting in San Diego, CA.
"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," Shah said.
"These findings further support how we as physicians can empower patients, especially those with precancerous conditions, with knowledge on reducing their cancer risk through dietary changes."
Two other studies by Flinders University investigated the relationship between diet and GI cancers. These cancers account for 25 percent of cases and one in three cancer deaths worldwide.
The researchers identified direct links between poor dietary choices and digestive cancers. Diets high in red and processed meats, fast foods, refined grains, alcohol, and sugary beverages were associated with an increased risk of GI cancers. Conversely, diets rich in fruits, vegetables, whole grains, fish, legumes, and dairy appeared to protect against these cancers and improve disease outcomes.
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Senior author Yohannes Melaku, PhD, from Flinders Health and Medical Research Institute noted that a diet high in healthy fats and vegetables that also limits the consumption of sugars and alcohol could potentially reduce the risk of bowel and other cancers.
"As awareness around bowel cancer grows, our research serves as a timely reminder of the power of nutrition in disease prevention. By adhering to healthy eating practices, we can take proactive steps in safeguarding our long-term health," Melaku says. "With the growing number of digestive cancers, such as bowel cancer, being diagnosed worldwide, and increasingly in people under 50 years old, it's time for action to protect people's digestive health."
Melaku emphasized that high-fiber foods promote healthy gut bacteria, which can reduce inflammation, underscoring the importance of fiber and healthy fats in the diet.
"Our findings not only reinforce established guidelines but also highlight dietary choices that can proactively protect against this disease such as upping your fiber intake," Melaku says. "Having a healthy diet is one of the simplest ways to improve our overall health and reduce the risk of diseases including cancers."
These findings align with guidelines from the World Cancer Research Fund and the American Institute for Cancer Research, which advocate for diets rich in whole grains, vegetables, fruits, and legumes, while limiting red and processed meat, sugary drinks, and processed foods. According to Melaku, the studies demonstrate the need for nutrition education and its impact on promoting healthy eating patterns to reduce GI risks.
"Whilst our results are promising, more work needs to be done with a greater focus on nutrition in clinical settings using nutritional biomarkers to better understand the relationship between diet and GI cancer," says Associate Professor Amy Reynolds, an author on the paper. "We need to understand how different dietary patterns may influence the risk of developing digestive cancers. We also want to see an increase in education around healthy eating which could lead to better health outcomes for those at risk for GI cancers."