Dietary supplement use in individuals living with cancer and other chronic conditions: a population-based study

Abstract

Objective: Cancer survivors are increasingly turning to complementary and alternative medicine (CAM) to manage short- and long-term treatment sequelae. Population-based data on relative use of dietary supplements among cancer survivors compared to those without a cancer history is lacking. Our objective was to compare supplement use among those with and without cancer and among those with and without other chronic conditions, and to identify correlates of supplement use by cancer status.

Design: Cross-sectional, population-based survey of participants in the 2003 CAM supplement to the 2001 California Health Interview Survey.

Subjects: Participants reporting a cancer diagnosis on the 2001 California Health Interview Survey or newly reported diagnosis on the 2003 survey (n=1,844) plus a random oversampling of racial/ethnic minorities (n=7,343).

Measures: Self-reported use of a multivitamin and 27 vitamins, minerals, herbs, and other natural products during the preceding 12 months.

Statistical analyses: Logistic regression analyses were performed with control for potential confounders.

Results: Adults with cancer or other chronic conditions had higher prevalence of supplement use than those reporting no illness. The independent effect of cancer was associated with vitamin use, whereas living with other chronic conditions was associated with all types of supplement use, except multivitamins. Correlates of supplement use were similar between cancer survivors and cancer-free individuals-being a woman, advancing age, and greater physical activity, fruit and vegetable intake, and other CAM use. Among cancer survivors, non-Hispanic whites had the lowest prevalence of herbal supplement use.

Conclusions: These results indicate that having a chronic medical condition is the major factor associated with supplement use. A diagnosis of cancer, by itself, does not have an independent effect on supplement use. This suggests that most supplement use among cancer survivors is directed at dealing with or preventing the exacerbation of a comorbid condition. Consumers and health professionals should be aware that there is limited information on the effects of dietary supplements taken concurrently with prescription and other over-the-counter medications.