Self-reported quality of life in users and nonusers of dietary supplements in cancer

To describe the Quality of Life (QoL) characteristics of users of dietary supplements vs nonusers.

A survey of 225 cancer patients presenting for treatment at Cancer Treatment Centers of America was completed between November 2001 and October 2003. A validated instrument assessed the use of 56 dietary supplements in the past month. Two validated questionnaires assessed QoL. Mean QoL scores were compared between the users and nonusers using univariate and multivariate linear regression.

Of 225 patients, 91 (40%) were males and 134 (60%) females. Sixty seven (30%) had breast cancer, 40 (18%) colorectal cancer, and 32 (14%) lung cancer. One hundred sixty four (73%) had used dietary supplements in the past month, while 61 (27%) had not. Mean European Organization for Research Treatment of Cancer QoL scores were significantly better among the users for physical and emotional function scales and fatigue, nausea, appetite loss, and constipation symptom scales adjusting for tumor site. In the stratified analysis, lung cancer patients did not show any statistically significant differences in QoL scores between the users and nonusers. Colorectal cancer patients demonstrated statistically significant differences in constipation symptom, with dietary supplement users having better QoL. Breast cancer patients demonstrated statistically significant differences in several QoL scale scores between users and nonusers.

Contrary to some of the previously published research, this study, conducted at a community hospital comprehensive cancer center that combines alternative treatment approaches with conventional cancer care, found better self-reported QoL among the users of dietary supplements, as compared to nonusers. The next step in this research is to prospectively evaluate the patterns of changing QoL in relation to dietary supplement use across the entire duration of cancer diagnosis and treatment.