Abstract
Background: This systematic review aimed to evaluate the efficacy and safety of dietary supplements in breast cancer patients, focusing on their impact on clinical outcomes, treatment-related side effects, and therapy adherence. Methods: Only RCTs investigating the effects of various orally administered supplements in adult breast cancer patients were included. Well-defined substances like vitamins, minerals, antioxidants, and specific herbal extracts were explored. The review excluded studies solely based on dietary interventions or non-supplemental approaches. The primary outcome assessed was quality of life. Secondary outcomes included disease-free survival, overall survival, tumor response, and biomarkers indicative of disease progression. Results: A total of 45 randomized controlled trials (RCTs) were included in this systematic review. Overall, supplementation was not associated with serious adverse events in the included trials. Vitamin D supplementation showed promise in some studies, with potential immunomodulatory and antioxidant effects, particularly when combined with other interventions. Omega-3 fatty acids and beta-glucan demonstrated potential in alleviating certain symptoms and improving quality of life. Studies on amino acids like acetyl-L-carnitine and L-arginine also yielded mixed results. Beta-glucan exhibited potential for immune-enhancing effects, while melatonin and creatine showed limited or no benefit for fatigue or muscle strength. Herbal extracts, including silymarin, curcumin, and EGCG, had varied effects. Curcumin studies presented mixed results. Silymarin showed potential for hepatoprotective effects. Conclusions: These findings highlight the potential of specific dietary supplements to improve various aspects of breast cancer care. However, the evidence is mixed across supplement types, and further research is needed to determine the most effective and safe approaches.