A very interesting, but very preliminary study just came out about breast cancer and walnuts. Could follow up research really show this to be true - that eating walnuts has an anti-breast cancer effect?? Animal studies find that multiple ingredients in walnuts (e.g.alpha linolenic acid, beta-sitosterol, a number of antioxidants such as ellagic acid) reduce the risk of cancer or slow its growth, or even increase tumor cell death. Researchers think this is true for human breast cancer also, and so a study was done looking at "gene expression" of breast cancer tumors. The question asked by the Marshall University (West Virginia) researchers was: Would eating 2 oz (14 halves) of walnuts daily for 2 to 3 weeks have an effect on the breast cancer tumors?
10 post-menopausal women had diagnostic breast cancer tumor biopsies done and then were randomly divided into 2 groups: 1) 5 of the women ate 2 oz of walnuts daily for the 2 to 3 weeks until breast cancer surgery, and 2) the other 5 avoided eating walnuts in the 2 to 3 weeks prior to breast cancer surgery. Otherwise the women ate their normal diets - a Western style diet.
The researchers noted that in the walnut eating group: "gene expression in the tumor was modified in ways expected to slow proliferation, reduce inflammation, reduce metastasis and to increase cancer cell death". The researchers also felt that consuming walnuts would decrease risk for cancer recurrence, and that there may be benefit from walnuts against many cancer types.
The researchers point out that another study published in 2016 (which was a review and analysis of 20 studies) concluded that "nut consumption, including peanuts, was associated with reduced risk of cancer and reduced all-cause mortality" (meaning death from any cause) - which agrees with the results of this study. In the 2016 study the beneficial health effect was for at least 28 grams (1 serving) of nuts per day. Bottom line: Enjoy consuming some nuts daily!
From Medical Xpress: Scientists tie walnuts to gene expressions related to breast cancer
New research from Marshall University links walnut consumption as a contributing factor that could suppress growth and survival of breast cancers.
Led by W. Elaine Hardman, Ph.D., a professor in the Department of Biomedical Sciences at the Marshall University Joan C. Edwards School of Medicine, a Marshall University team revealed that consumption of two ounces of walnuts a day for about two weeks significantly changed gene expression in confirmed breast cancers. This pilot, two-arm clinical trial is the latest of a series of related studies at Marshall University related to dietary walnut links to tumor growth, survival and metastasis in breast cancer. The work is described in a March 10 paper published in the journal Nutrition Research.
"Consumption of walnuts has slowed breast cancer growth and/or reduced the risk of mammary cancer in mice," Hardman said. "Building on this research, our team hypothesized that walnut consumption would alter gene expression in pathologically-confirmed breast cancers of women in a direction that would decrease breast cancer growth and survival."
In this first clinical trial, women with breast lumps large enough for research and pathology biopsies were recruited and randomized to walnut consuming or control groups. Immediately following biopsy collection, women in the walnut group began to consume two ounces of walnuts per day until follow-up surgery. Pathological studies confirmed that lumps were breast cancer in all women who remained in the trial. At surgery, about two weeks after biopsy, additional specimens were taken from the breast cancers.
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.