Walnuts may reduce breast cancer growth, study shows

Eating walnuts may suppress breast cancer and increase patient survival, according to new research from Marshall University in Huntington, West Virginia, which was published in the journal Nutrition Research. The study was funded in part by the California Walnut Commission.  

Researchers conducted a two-part clinical trial to examine the link between walnut consumption and tumor growth, survival, and metastatic in breast cancer, as described in a statement released by the university. In the first trial, women with breast lumps large enough for research and pathology biopsies were recruited and randomized to either walnut consuming or control groups. Participants immediately received biopsies and were scheduled for surgery about two weeks later. Women in the walnut group consumed two ounces of walnuts per day leading up to surgery.

Study participants who were found to have breast cancer moved on to the second clinical trial. At surgery, additional specimens were taken from the breast cancers, the study said.

Changes in gene expression in the surgical specimen compared to baseline were determined in each individual woman in walnut-consuming (n = 5) and control (n = 5) groups. RNA sequencing expression profiling revealed that expression of 456 identified genes was significantly changed in the tumor due to walnut consumption. Ingenuity Pathway Analysis showed activation of pathways that promote apoptosis and cell adhesion and inhibition of pathways that promote cell proliferation and migration, the study said.

These results support the hypothesis that, in humans, walnut consumption could suppress growth and survival of breast cancers, researchers said. Additional research through a larger-scale study would be needed to clinically confirm that walnut consumption actually does reduce the risk of breast cancer or breast cancer recurrence.