Exploring biologically-based complementary and alternative medicine use among Irish cancer survivors: findings from a national survey

Background: Biologically based complementary and alternative medicine (BBCAM) includes special diets, dietary supplement and herbal remedies, not prescribed by a doctor or dietitian. The use of BBCAM is common among cancer survivors. BBCAM can interact with conventional treatments and unregulated products may cause harm. This study aimed to determine the prevalence, types, and motivations for BBCAM use among cancer survivors. Methods: A survey assessed clinical characteristics and BBCAM use in participants >18 yrs who had received cancer treatment in Ireland from 2018 to 2022. Results: Amongst 295 respondents (77% female, mean age 53 yrs), BBCAM use increased from 28% pre-diagnosis to 34% post-diagnosis (p < 0.001). For BBCAM users (n = 97, 33%), “daily-use” increased from 38% to 72% (p < 0.001) post-diagnosis. Common types included: mineral/vitamin supplements (84%), dietary supplements (e.g. turmeric, coenzyme-Q10) (78%), herbal remedies/botanicals (e.g. mistletoe, St. John’s Wort, echinacea, ginseng) (50%), cannabis (21%), and other natural products (laetrile, shark cartilage, apricot kernels) (19%). Biological medicines (GcMAF, immuno-augmentative therapy) were used by 12% of BBCAM users. Special diets including dairy free (32%), gluten-free (19%), intermittent fasting (17%), ketogenic diet (15%), juicing/detox (10%) were also common. Perceived benefits included: improved well-being (63%) and reduced psychological stress (59%). Conclusion: BBCAM use increases after a cancer diagnosis. Patient perceived benefits highlight potential gaps in the current healthcare model, indicating a need for greater emphasis on safe survivorship care.