Study finds link between childhood cancer, poor dietary quality in adulthood

The epidemiological study, performed by researchers from the Friedman School of Nutrition Science and Policy at Tufts University and St. Jude Children's Research Hospital, looked at how the diets of childhood cancer survivors compare with the 2010 Dietary Guidelines for Americans, whether survivors' consumption of key nutrients and food groups meet the recommended levels, and whether cancer and treatment may impact survivors' long-term dietary intake. The results were published online in the Journal of Nutrition on Oct. 19.

In a cohort of 2,570 adult survivors of childhood cancer, the team of researchers found particularly low intakes of whole grains but excessive intakes of sodium and empty calories, i.e. calories from solid fats and added sugars. The mean intake of whole grains (1.2 servings/day) was less than half of the recommended intake (3 servings/day), whereas the sodium intake (3,566 mg/day) was substantially higher than the upper intake level (<2,300 mg/day). Among childhood cancer survivors, calories from added sugars and solid fats each contributed to 14 percent and 20 percent of the total calories, respectively, whereas the 2015 Dietary Guidelines for Americans recommend the percent of calories from both added sugars and solid fats be less than 20.

"When compared to existing dietary recommendations, we found that childhood cancer survivors consumed below the recommended intake for fiber, potassium, magnesium, vitamin D, calcium and vitamin E, and excessive levels of sodium and saturated fat, both of which are risk factors for chronic diseases such as cardiovascular disease, diabetes and obesity," said lead and corresponding author Fang Fang Zhang, M.D., Ph.D., assistant professor at the Friedman School of Nutrition Science and Policy at Tufts University in Boston. "Healthy eating can improve the physical and mental functioning of childhood cancer survivors. Our findings support the need to incorporate nutrition into cancer care."

To assess diet quality, the researchers calculated the mean Healthy Eating Index (HEI)-2010 total score, a measure of diet quality using adherence to the Dietary Guidelines for Americans, as well as component scores and the mean dietary intake of nutrients. The HEI-2010 total score ranges from zero (non-adherence) to 100 (perfect adherence); the cohort's mean HEI-2010 total score was 57.9.

The researchers also reported that cancer survivors who were diagnosed before age five had a lower diet quality compared to those who were diagnosed at age five or older, and survivors who had received high radiation doses to the abdomen had a lower quality diet than those who received low doses.

"Survivors of childhood cancer have a high prevalence of chronic health problems that may be exacerbated by poor nutrition," said Melissa Hudson, M.D., director of the St. Jude Children's Research Hospital Division of Cancer Survivorship. "The findings of this study emphasize the importance of integrating nutritional services and interventions to promote healthy dietary habits in childhood cancer patients during treatment and throughout survivorship care."

The study assessed the diets of 2,570 adult survivors of childhood cancer enrolled in the St. Jude Lifetime Cohort using a self-administered Block Food Frequency questionnaire. Cancer diagnosis and treatment exposure were abstracted from medical records. The researchers calculated the mean HEI-2010 total score and component scores and the mean dietary intake of nutrients, as well as evaluated whether survivors' dietary intake of nutrients meet the nutrition goals by comparing mean intake to recommended intake, estimated based on the age-sex groups of the Dietary Reference Intakes.

While the study did not compare survivors' diets to diets of those who have not had cancer, Zhang recently reported that adult cancer survivors have "worse overall diet quality compared to age- and sex-matched controls in the National Health and Nutrition Examination Survey." The researchers note that the present study does not include supplemental intake of vitamins and minerals.