Study Shows Walnuts May Protect Against Prostate Cancer

September is Prostate Cancer Awareness Month and a perfect time to focus on the importance of nutrition in the fight against this disease. New animal research published in Cancer Investigation, indicates eating 2 oz. of walnuts may prevent prostate cancer tumor incidence and progression.

Researchers at the University of Texas Health Science Center in San Antonio found only 18% of mice fed a walnut enriched diet developed prostate cancer tumors compared to 44% on the control diet and of those that developed cancer, tumors were one-fourth the average size compared to the control diet. These animal studies are provided as background and used to formulate hypotheses for addition research that is needed to confirm the findings on humans.

"The walnut portion was not a large percentage of the diet," said study senior author Russel Reiter, Ph.D., professor of cellular and structural biology at the Health Science Center. "It was the equivalent to a human eating about 2 ounces, or two handfuls, a day, which is not a lot of walnuts." The findings are significant, for prostate cancer is the second leading cause of death in American men, with one in six being diagnosed. A healthy, predominantly plant-based diet, is a key component of cancer prevention according to recommendations by the American Institute for Cancer Research. Walnuts offer a powerful nutrient package that includes alpha-linolenic acid (plant-based omega-3 fatty acid), antioxidants and phytosterols. A one ounce/28 gram serving of walnuts provides 2.5 grams of ALA[1].

"We found the results to be stunning because there were so few tumors in animals consuming the walnuts and these tumors grew much more slowly than in the other animals," said Dr. Reiter. "We were absolutely surprised by how highly effective the walnut diet was in terms of inhibition of human prostate cancer cells."

The role of walnuts in cancer prevention has been demonstrated through ten research projects. "The data to date suggest that using walnuts on a regular basis in the diet may be beneficial to deter, prevent or delay some types of cancer, including breast and prostate," Dr. Reiter said. These study findings provide evidence that walnuts can play a role in cancer prevention, however more research is needed before understanding its application to humans.



[1] One ounce of walnuts provides 18g of total fat, 2.5g of monounsaturated fat, 13 g of polyunsaturated fat, including 2.5 grams of alpha-linolenic acid - the plant-based omega-3; 2g of fiber; 4g of protein, 3.68 mmol/28 g of antioxidants. (