A UConn School of Medicine clinical trial has found that consuming walnuts can significantly reduce inflammation and lower the risk of colon cancer by producing urolithins, potent anti-inflammatory compounds formed in the gut.
The University of Connecticut School of Medicine has unveiled new research highlighting the benefits of walnut consumption in reducing inflammation and lowering the risk of colon cancer. The study, published in the April edition of Cancer Prevention Research, demonstrates how walnuts can positively impact systemic inflammation and offer protective benefits against colon cancer.
The key to these benefits lies in ellagitannins, a type of plant-derived polyphenol compound abundant in walnuts. When metabolized by the gut microbiome, ellagitannins transform into urolithins, powerful anti-inflammatory molecules.
“Ellagitannins in the walnut are importantly providing the anti-inflammatory and anti-cancer properties that we’re seeing in patients in our clinical trial research, particularly the gut’s conversion of ellagitannins to a potent anti-inflammatory agent, urolithin A,” the research team reported.
Daniel W. Rosenberg, HealthNet Chair in Cancer Biology and investigator in the Center for Molecular Oncology, and his multidisciplinary team at UConn School of Medicine included 39 participants aged 40 to 65 who were at elevated risk for colon cancer.
These individuals adhered to a curated diet that initially excluded all ellagitannin-rich foods for a week to reset their urolithin levels to near zero. They then incorporated walnuts into their diet for three weeks under close monitoring.
The findings showed that elevated levels of urolithin A, derived from walnut consumption, correlated with a reduction in inflammatory markers in blood, urine and fecal samples. This effect was more pronounced in obese participants with a heightened capacity to form urolithins.
Advanced imaging technology revealed that high levels of urolithin A were linked to reduced levels of several proteins associated with colon polyps and potentially advanced forms of colon cancer.
The study’s pivotal discoveries build upon the earlier research of Masako Nakanishi, an assistant professor in the Rosenberg Lab, who demonstrated walnuts’ beneficial and anti-cancer properties in cancer-prone mice, laying the groundwork for this human clinical trial.
“Urolithin A has a very positive influence on inflammation and maybe even cancer prevention,” Rosenberg said in a news release. “Our study proves that dietary supplementation with walnuts can boost the general population’s urolithin levels in those people with the right microbiome, while significantly reducing several inflammatory markers, especially in obese patients.”
This study’s groundbreaking implications underscore the potential long-term health benefits of walnuts.
“Our study provides strong rationale for dietary inclusion of walnut ellagitannins for cancer prevention,” concluded Rosenberg. “Nutrients from walnuts can contribute to reduced cancer risk. There are many potential benefits one can get from eating walnuts, with so little downside risk, that just grabbing a handful every day is really something that you can easily do for your long-term health benefit.”
Supported by the American Institute for Cancer Research, the California Walnut Commission and the National Cancer Institute, this research breaks new ground in understanding how simple dietary changes can have profound health impacts.
Source: University of Connecticut