New research suggests a link between walnut consumption and lower colorectal cancer risk. Learn about the molecule in walnuts that contributes to this potential benefit and how it impacts gut health.
According to figures from the National Cancer Institute, colorectal cancer, also known as colon cancer, affects more than 47,000 people in France each year and causes 17,000 deaths, making it the second leading cause of cancer death. While several risk factors, such as alcohol and red meat consumption, are known, there is one food that could help prevent the risk of colorectal cancer: walnuts.
The action of a molecule present in nuts
Published on April 1, 2025, in the journal Cancer Prevention Research, a study conducted by researchers at the University of Connecticut (UConn) in the United States highlighted the anti-inflammatory, and potentially anti-cancer, effects of nut consumption.
These foods contain ellagitannins, which, once digested by the gut microbiota, are converted into urolithins. Among these, urolithin A stands out for its significant anti-inflammatory properties.
In this study, thirty-nine participants aged 40 to 65, all at high risk of colorectal cancer, followed a strict dietary protocol based on nuts rich in ellagitannins. The results were clear: a significant decrease in inflammatory markers in the blood, urine, and stool was observed, particularly in obese patients with a high capacity to produce urolithin A.
The importance of nuts in the diet
“The ellagitannins in walnuts are essential for the anti-inflammatory and anti-cancer properties we observed in patients in our clinical study, particularly through the conversion of these compounds by the intestine into a potent anti-inflammatory agent, urolithin A,” summarised Dr. Daniel W. Rosenberg, lead author of the study, in a press release.
“This study provides a strong rationale for the dietary inclusion of walnut ellagitannins for cancer prevention,” he adds, stating that colonoscopies performed at the end of the study confirmed the benefits.
Eating a handful of nuts a day could therefore be a simple but important step to protect your intestinal health and reduce the risk of colorectal cancer.
This article was originally published by on the Marie Claire France website.
