Yale study: Eating nuts may reduce risk of colon cancer recurring
Published 7:18 pm, Wednesday, February 28, 2018
NEW HAVEN — Eating nuts may help survivors of colon cancer prevent the disease from recurring, according to a Yale Cancer Center study.
The clinical trial followed 826 people who had suffered stage 3 colon cancer for an average of 6.5 years after surgery and chemotherapy, according to a Yale press release. It found that those who ate at least two 1-ounce servings of tree nuts each week were 46 percent less likely to have the cancer return and had a 57 percent reduction in mortality, regardless of cause.
When peanuts — which are legumes, not nuts — were included in the findings, patients had a 42 percent better chance of avoiding a recurrence of colon cancer.
“People who eat nuts … after surgery for colon cancer really do better,” said Dr. Charles Fuchs, director of the Yale Cancer Center and senior author of the study. Fuchs is also physician-in-chief of Smilow Cancer Hospital.
Fuchs and his fellow researchers undertook the study because of parallels between type 2 diabetes and colon cancer.
The same unhealthful lifestyles that can lead to diabetes — obesity, a sedentary lifestyle and a high-carbohydrate diet — are also suspected of increasing the chance of developing colon cancer again or dying from it, Fuchs said. Since “there’s been a growing body of literature … that people who eat nuts appear to have a lower risk of type 2 diabetes,” the researchers thought the same might be true of colon cancer, he said.
“To our pleasant surprise, in the same way that eating nuts reduces your risk of diabetes, it also reduces your risk of colon cancer, if you’ve been treated for it,” Fuchs said.
It’s less clear, but possible, that eating nuts can help prevent colon cancer from developing, he said.
A previous study that Fuchs helped lead, published in 2013 in the New England Journal of Medicine, found that “people who ate nuts regularly had a lower rate of mortality” from any disease.
Earlier studies also have linked consumption of nuts with reducing insulin resistance, according to the release. Insulin breaks down sugar in the blood and when the body becomes insulin-resistant, it can lead to diabetes.
“These studies support the hypothesis that behaviors that make you less insulin-resistant, including eating nuts, seem to improve outcomes in colon cancer,” Fuchs said, in the release. “However, we don’t know yet what exactly about nuts is beneficial.”
The connection between diabetes and colon cancer can be found at the cellular level, in what are known as energy balance pathways, Fuchs said. “We are potentially now identifying those pathways. If you know the cellular pathway, the molecular mechanism as it were, that drives colon cancer, that gives you a clue to treatment.”
“These findings are in keeping with several other observational studies that indicate that a slew of healthy behaviors — including increased physical activity, keeping a healthy weight, and lower intake of sugar and sweetened beverages — improve colon cancer outcomes,” said Dr. Temidayo Fadelu, a postdoctoral fellow at Dana-Farber Cancer Institute in Boston and lead author of the paper, in the release. “The results highlight the importance of emphasizing dietary and lifestyle factors in colon cancer survivorship.”
Fuchs also said nuts satisfy hunger better than carbohydrates and that their fat content doesn’t appear to be an issue. A one-ounce serving of almonds (about 24 nuts) has about 200 calories and 14 grams of fat. “People ask me if increasing nut consumption will lead to obesity, which leads to worse outcomes,” he said in the release. “But what’s really interesting is that in our studies, and across the scientific literature in general, regular consumers of nuts tend to be leaner.”
A previous analysis of the same group of patients found that coffee also appears to reduce recurrence and mortality in colon cancer survivors.
Fuchs said that when he talks to patients, “first and foremost I talk about avoiding obesity, exercising regularly, and staying away from a high-carbohydrate diet. Then we talk about things like coffee and nuts. If you like coffee or nuts, enjoy them, and if you don’t, there are many other helpful steps you can take.
“Overall, we are working to apply the same rigorous science to the understanding of diet and lifestyles in the colon cancer patient population that we apply to defining new drugs,” Fuchs said in the release.
Besides financial support from the National Cancer Institute, the research was also sponsored by Pfizer Oncology and the International Tree Nut Council Nutrition Research and Education Foundation, according to the release. The private sponsors had no role in designing, conducting or analyzing the study and did not review the paper, the release said.
Contact Ed Stannard at firstname.lastname@example.org or 203-680-9382.