Tree nuts are associated with significantly better survival of colon-cancer patients whose disease has spread to the lymph nodes after standard treatment with chemotherapy and surgery, according to a recent study of Stage 3 colon-cancer patients. Stage 3 means the colon cancer has reached surrounding lymph nodes but has not spread to distant organs.

With at least twice-weekly consumption of one ounce (one serving) of nuts, Stage 3 colon-cancer patients who were post-chemotherapy and postsurgery had a 42% lower chance of cancer recurrence and a 57% lower chance of death from the disease, compared with patients who did not eat nuts. The benefits were found only in patients who ate tree nuts such as walnuts and almonds, not those who ate peanuts or peanut butter. Peanuts actually are legumes.

The study showed an association and did not prove cause and effect. And there is no proof that nuts are effective on their own—they must be eaten within an overall healthful diet and as part of a lifestyle that includes regular exercise, maintenance of proper weight, and lower intake of sugar and sweetened beverages.

The mechanism by which tree nuts may contribute to health is unknown. Nuts have anti-inflammatory properties and may have a positive effect on insulin processing. And they contain a complex mixture of healthful proteins, fiber and multivitamins. Eating nuts is not a substitute for standard therapy—all patients studied had chemotherapy and surgery, and nut consumption must be part of an overall lifestyle that promotes better health. Based on this study and other studies, lifestyle can lower the risk for a recurrence of colon cancer.