New Study Finds Walnuts Reduce Inflammation and May Lower Colon Cancer Risk

Recent research highlights the significant health benefits of including walnuts in your diet. A clinical trial conducted by researchers at the UConn School of Medicine, published in the April edition of Cancer Prevention Research, reveals that eating walnuts can decrease systemic inflammation and potentially reduce the risk of colon cancer. The study underscores the role of walnut-derived compounds called ellagitannins, which are metabolized by the gut microbiome into urolithins—a group of anti-inflammatory molecules with cancer-inhibiting properties.

Ellagitannins in walnuts serve as precursors to urolithin A, a potent anti-inflammatory agent. According to Daniel W. Rosenberg, Ph.D., the research team observed that higher levels of urolithin A production in the gut correlated with lower inflammatory markers in blood, urine, and fecal samples, as well as beneficial effects on immune cells within colon polyps. This supports the idea that walnut consumption can promote colon health.

The clinical trial involved 39 participants aged 40 to 65, all at increased risk for colon cancer. Participants followed a controlled diet, avoiding ellagitannin-rich foods for a week before the study, then consuming walnuts over three weeks while being monitored. Afterward, each participant underwent a colonoscopy. The researchers discovered that elevated urolithin A levels were associated with decreased levels of proteins linked to advanced colon cancer, such as vimentin, suggesting a protective effect.

In addition, advanced imaging techniques allowed scientists to observe cellular interactions within colon polyps, revealing that high urolithin A levels corresponded with reduced expression of proteins involved in cancer progression. These findings build on earlier animal studies and indicate that walnuts may play a role in cancer prevention through their influence on inflammation and cellular health.

Dr. Rosenberg emphasized that incorporating walnuts into the diet offers a simple, low-risk strategy for long-term health benefits. He advocates for regular walnut intake, noting their potential to boost urolithin levels, reduce inflammation, and support colon health. The study advocates for the nutritional inclusion of walnuts as part of a balanced diet to aid in cancer prevention.