By Brierley Wright, M.S., R.D., January/February 2009
Walnuts are often called a “superfood”—studies link them with glucose control, strong bones and heart health. Now new research in the journal Nutrition and Cancer suggests walnuts may thwart the growth of breast cancer. In a study out of Marshall University School of Medicine in West Virginia, researchers substituted 18.5 percent of the diet of one group of mice with walnuts (equivalent to a human eating two ounces per day); the other group was fed a calorically equivalent, but walnut-free, diet. After 34 days, the growth rate of tumors in the walnut eaters was half that of the mice who ate no walnuts.
Experts think all types of cancer are linked to inflammation. Walnuts’ anti-inflammatory properties—which could come from the omega-3 fat alpha-linolenic acid, phytosterols or antioxidants—may give them their tumor-fighting potential. “Individually all three have been shown to suppress tumors—it could be just one or it could be all three working synergistically,” explains Elaine Hardman, Ph.D., lead researcher and associate professor of biochemistry and microbiology at Marshall.
While the study results are promising, the research is preliminary. Plus, eating the study dose of two ounces supplies 370 calories, which is equivalent to what you’d get in 11⁄2 cups of whole-grain cereal, a cup of low-fat yogurt and an orange. Still, “walnuts can be part of a healthy diet that can reduce your risk for cancer,” says Hardman.