Diet quality is directly associated with quality of life in breast cancer survivors

Summary Purpose To determine whether there is a direct relationship between diet quality and quality of life in breast cancer survivors. Methods Subjects (n = 714) were members of the Health, Eating, Activity, and Lifestyle study, a study of breast cancer prognosis conducted in three areas of the western United States. Approximately 2 years after entry to this study, diet data were collecting using food frequency questionnaires. These data were used to classify diet quality using the Diet Quality Index. Approximately 10 months later, data on quality of life were gathered using the Medical Outcomes Study 36-Item short form health survey. Results After controlling for age, education, race/ethnicity, body mass index, stage of disease, and time from diagnosis to quality of life measurement, women with excellent diet quality had significantly better scores than women with poor diet quality for overall mental health functioning and for 3 of 4 mental health subscale scores and 2 of 4 physical health subscale scores. Conclusion Post-diagnosis diet quality is directly associated with subsequent mental and physical functioning in breast cancer survivors. This association is stronger for mental functioning than for physical functioning. The association remains strong after control for potential confounding variables.