When taking only tree nuts into account, the research team found that the risk of a colon cancer recurrence was 46 percent lower in those who ate tree nuts than those who did not. In addition, people who ate tree nuts had a 53 percent reduced odds of colon cancer death compared with the non-consuming group.
"Numerous studies in the fields of heart disease and diabetes have shown the benefits of nut consumption, and we felt that it was important to determine if these benefits could also apply to colorectal cancer patients. Patients with advanced disease who benefit from chemotherapy frequently ask what else they can do to reduce their chances of recurrence or death, and our study is an important contribution to the idea that modifying diet and physical activity can be beneficial," said lead study author Temidayo Fadelu, a Clinical Fellow in medicine at Dana Farber Cancer Institute.
However, data from a secondary analysis revealed that the effects were exclusive to tree nuts. According to the research team, there was no significant reductions in the risk of colon cancer recurrence and subsequent death among patients who ate peanuts or peanut butter. The study authors inferred that legumes such as peanuts may have a different metabolic composition compared with tree nuts.
"This study shows that something as simple as eating tree nuts may make a difference in a patient's long-term survival. Nut consumption and a healthy diet are generally factors that clinicians and patients should perhaps pay attention to as they design the approach to treatment for colorectal cancer...It should be emphasized that the authors are not suggesting that eating nuts should be considered a substitute for standard chemotherapy and other treatments for colon cancer, which have dramatically improved survival. Rather, patients with colon cancer should be optimistic, and they should eat a healthy diet, including tree nuts, which may not only keep them healthier, but may also further decrease the chances of the cancer coming back," said Dr. Daniel F. Hayes, president of the American Society of Clinical Oncology (ACSO).
The findings were slated for presentation at the 2017 ASCO Annual Meeting in Chicago.
A large number of studies have previously demonstrated that eating nuts may help reduce the risk of developing colon cancer. For instance, a study conducted by researchers at the Seoul National University College of Medicine in South Korea revealed that consuming a serving of nuts three or more times a week may keep the condition in check. As part of the study, the research team examined more than 900 patients with colon cancer and compared their diets with nearly 2,000 otherwise healthy individuals.
The study revealed that men who ate three or more servings of nuts had a 69 percent lower odds of developing colon cancer than those who did not. The researchers also found that women who had high nut intake were 81 percent less likely than non-consumers to develop the disease. The findings were presented at the annual meeting of the American Association for Cancer Research.