Dietary supplement use among elderly, long-term cancer survivors

The purpose of the present study was to assess dietary supplement use and its association with micronutrient intakes and diet quality among older (≥65 years), long-term survivors (≥5 years post-diagnosis) of female breast, prostate, and colorectal cancer.

The sample included 753 survivors who participated in telephone screening interviews to determine eligibility for a randomized diet and physical activity intervention trial entitled RENEW: Reach-out to ENhancE Wellness in Older Cancer Survivors. Telephone surveys included two 24-hour dietary recalls and items regarding supplement use (type, dose, and duration). Nutrient intakes were compared to Dietary Reference Intakes (DRIs). Diet quality was assessed using the revised Healthy Eating Index (HEI). Descriptive statistics and multivariate logistic regression were used in this cross-sectional study.

A majority of survivors (74%) reported taking supplements, with multivitamins (60%), calcium/vitamin D (37%), and antioxidants (30%) as the most prevalent. Overall proportions of the total sample with dietary intakes below Estimated Average Requirements (EARs) were substantial, although supplement users had more favorable mean HEI scores (P < 0.01) and nutrient intakes for 12 of the 13 vitamins and minerals investigated (P values < 0.05). Supplement use was positively associated with older age (≥70 years) (odds ratio (OR)=1.70; 95% confidence interval (95% CI)=1.17, 2.46) and female gender (OR=1.49; 95% CI=1.04, 2.13), and negatively associated with current smoking (OR=0.40, 95% CI=0.21, 0.76). Individuals scoring higher on the Total Fruit (OR=1.12, 95% CI=1.01, 1.23), Whole Grain (OR=1.14, 95% CI=1.04, 1.25), and Oil (OR=1.10, 95% CI=1.01, 1.11) components of the HEI were significantly more likely to take supplements, while those scoring higher on the Meat and Beans category (OR=0.81, 95% CI=0.71, 0.93) were significantly less likely to take supplements. Compared to those with less than a high school education, survivors with a professional or graduate degree were significantly more likely to use supplements (OR=2.18, 95% CI=1.13, 4.23).

Demographic, disease, and health-related correlates of supplement use follow similar trends observed in the general population as well as previous reports from other cancer survivor populations. Supplement use may reduce the prevalence of nutrient inadequacies in this population, though survivors who use supplements are the least likely to need them.

Supplement use may be an effective means for many survivors to achieve adequate nutrient intakes; however, open communication between healthcare providers and survivors is needed to ensure potential concerns are addressed as supplement use may not always be beneficial.