Diet in the Wake of Cancer

Last month, Americans read the latest nutrition news with horror—researchers had established a link between cured meats and cancer. Even so, most people probably won’t be skipping bacon at brunch this weekend—we’re often slow to change our diets based on what’s healthiest for us. But what if you’ve already had the fight of your life and won it? Do cancer survivors eat more or less healthy diets than the average American?

That’s what Fang Fang Zhang, an assistant professor of epidemiology at the Friedman School, and her colleagues sought to find out in their recent study, published last month in Cancer, the journal of the American Cancer Society. The team looked at the self-reported diets of more than 1,500 adults participating the National Health and Nutrition Examination Survey from 1999 to 2010 to see how closely people managed to follow federal dietary guidelines.

They found that people who have survived cancer eat fewer green vegetables and whole grains than people without a history of cancer do. Survivors also weren’t getting enough fiber, vitamin D, vitamin E, potassium or calcium, and were taking in too much sugar, fat and sodium, as defined by the 2010 Dietary Guidelines for Americans issued by the Department of Agriculture and the Department of Health and Human Services. 

“Our findings reinforce the need for dietary intervention in this high-risk population,” says Zhang. “It is remarkable that cancer survivors are still burdened by suboptimal dietary intake. Not getting enough fiber and having too many empty calories are established risk factors for many chronic health conditions.”

Overall, cancer survivors had a total Healthy Eating Score of 47.2 out of 100, compared with 48.3 in adults without a history of cancer. Cancer survivors with less education and those who were current smokers had significantly worse diet quality than their counterparts. Among those who had battled one of the four major types of cancer in the United States—breast, prostate, colorectal and lung—breast cancer survivors adhered to the federal diet guidelines most closely. Lung cancer survivors had the worst diet quality.

Zhang adds that the study’s design cannot determine whether cancer survivors developed poor eating habits before or after their diagnosis. If it’s the latter, it could be the result of cancer treatments causing changes in taste preferences or high levels of emotional stress.

Either way, Zhang notes, “cancer survivors have significantly higher chronic disease burden than the general population. Even though the difference in diet quality does not sound large, improving eating patterns can be a particularly important focus for cancer survivors to reduce chronic disease burden and achieve a long and healthy life.”

Zhang’s findings indicate that nutrition should be integrated into routine care for cancer patients. Oncologists can reinforce the importance of a healthful diet, and can refer patients to registered dieticians who are expert in oncology care, she adds.

“Many cancer survivors are highly motivated to seek information about food choices and dietary changes to improve their health,” says Zhang. “Future research is needed to understand how to help survivors make positive behavioral changes, including diet.

Jacqueline Mitchell can be reached at jacqueline.mitchell@tufts.edu.