Walnuts are a tasty snack on their own, not to mention an excellent complement to salads, cookies, ice cream and cakes. Not only are they a good source of protein, but a healthy source of much sought-after healthy fats. This is good news!
But here is even better news: According to a recent study, walnuts might have a new and compelling credit added to their repertoire: lowering the risk of breast cancer. The study, led by Elaine Hardman of Marshall University's Joan C. Edwards School of Medicine compared the effects of a typical diet and a diet containing walnuts across the lifespan of the mice—through the mother from conception through weaning and by eating the food directly.
The amount of walnut in the test diet was equal to about 2 ounces a day for humans, Hardman said.
The study, which was funded by grants from the American Institute for Cancer Research and the California Walnut Commission, and published in the journal Nutrition and Cancer, found that the group of mice that had a diet that included walnut at both stages (through the mother and then in their own diets) developed breast cancer at less than half the rate of the group with the typical diet.
The study also found that in cases where the test mice DID develop breast cancer, the number of tumors and their sizes were significantly smaller.
The researchers attempted to determine the precise mechanism for the reduction in breast cancer incidence. Using genetic analysis, they found that the walnut-containing diet changed the activity of multiple genes that are relevant to breast cancer in both mice and humans. However, other testing showed that increases in omega 3 fatty acids did not fully account for the anti-cancer effect and found that tumor growth decreased when dietary vitamin E increased, Hardman said.
So while the jury is still out on the precise cause for walnuts’ apparent role in reducing breast cancer risk.