Exploring dietary changes and supplement use among cancer patients in Norway: prevalence, motivations, disclosure, information, and perceived risks and benefits: a cross sectional study

Cancer is the leading cause of death in Norway, with prostate, breast, lung, and colon cancers being the most prevalent types. Adopting a healthy and varied diet can help reduce cancer risk and recurrence. However, access to dietary counselling remains limited for cancer patients in Norway. This study aimed to investigate the prevalence of dietary supplement use and dietary changes made by cancer patients and survivors. Additionally, it sought to explore the reason(s) for such practices, communication with healthcare providers, sources of information, and reported benefits and potential harms resulting from these changes and supplement use. Conducted in collaboration with the Norwegian Cancer Society (NCS), this online cross-sectional study targeted members of their user panel who had either current or previous cancer (n = 706). The study took place in September/October 2021, utilizing a modified cancer-specific version of the International Questionnaire to Measure Use of Complementary and Alternative Medicine (I-CAM-Q). Out of 468 participants (315 women and 153 men), 67.2% consented to participate. Between-group analyses were conducted using Pearson chi-square tests and Fisher exact tests for categorical variables, while independent sample t-tests were applied for continuous variables. The majority of the participants (97%) reported making changes to their diet (78%) and/or incorporating dietary supplements (73%) in response to their cancer diagnosis. The primary goal of these changes was to strengthen their body and immune system. Almost half of the participants (49%) reported that they found these changes beneficial and discussed them openly with their healthcare providers, with family physicians being the most common point of discussion (25%). Adverse effects were reported by only a few participants, mostly mild. Information about dietary changes and supplements was primarily sourced from the internet or healthcare providers. This study highlights that most individuals affected by cancer attribute to dietary adjustment. It also emphasizes the importance of addressing adherence to dietary recommendations and using reliable sources of information. Additionally, the study highlights the potential, yet currently underutilized, role of healthcare professionals in initiating dialogues about dietary interventions to address any unmet needs of patients. Such proactive engagement may contribute to the promotion of reliable sources of information and the prevention of non-evidence-based and potentially harmful diets or supplement adoption.