A new study by the Journal of Nutritional Biochemistry has revealed the positive impact of walnuts on micro-ribonucleic acids (miRNA), the nucleotides that are involved in altering gene expression. Previous studies have documented the health benefits associated with reducing cardiovascular disease and diabetes.
The current study wanted to explore the epigenetic changes (environmental factors) associated with Walnut consumption. Cancer is a global problem. Colorectal cancer is the third most common prevalent cancer worldwide and is second to only lung cancer as the leading cause of death in Western Countries.
“Our research demonstrates that a walnut diet causes significant changes in the expression profile of miRNAs in localized colorectal cancer tissue, and that a walnut diet incorporates protective fatty acids in the colonic tumor either through its direct effects or through additive or synergistic effects of multiple other compounds present in walnuts,” said Dr. Mantzoros. “While future studies are needed, we’re optimistic of the role of miRNAs as biomarkers of disease and prognosis, and may demonstrate a potential therapeutic target for colorectal cancer treatment.”
The researchers used two groups of mice to investigate the epigenetic impact of walnuts. One group was fed the equivalent of two servings (2 ounces) per day of walnuts for humans for 25 days, while the second group received a similar control diet with no walnuts. Walnut-fed mice had key miRNA positively engaged, which affects cancer cell inflammation, vascularization (blood supply) and proliferation.
The improvement in miRNA expression was associated with an increase in the total amount of omega-3 fatty acids, including plant-based alpha-linolenic acid (ALA), in the tissue compared to the mice fed the control diet. Tumors in the walnut research group were associated with significant increases in α-linolenic, eicosapentaenoic, docosahexaenoic and total omega-3 acids, and a decrease in arachidonic acid, as compared to the control diet.
A smaller tumor size was associated with greater percentage of omega-3s in tumor tissues, suggesting that ALA may provide a preventative benefit against cancer. ALA is an essential fatty acid responsible for reducing the inflammatory metabolic process in the body. Walnuts are the only nut that contain a significant source of alpha-linolenic acid (ALA) (2.5 grams per ounce).