Abstract Context Breast cancer is the most common malignant tumor among women worldwide, with clinical stage and molecular subtype being key prognostic factors. Its causes are multifaceted, involving modifiable risk factors like physical activity, obesity, diet, and breastfeeding. Diet influences various aspects of breast cancer, including its development, prevention, prognosis, and treatment results. During treatment, lifestyle and dietary modifications can improve health-related quality of life (HRQoL), although what the most effective approaches are is still uncertain. Objective To systematically review and synthesize the effects of various dietary interventions on HRQoL in women with a confirmed diagnosis of breast cancer who are undergoing chemotherapy and radiotherapy. Data Sources A literature search of Medline, Embase, and the Cochrane Library databases was conducted up to March 2026, with no publication date restrictions. Data Extraction Three reviewers screened records based on predefined eligibility criteria, extracting data on participants, dietary interventions, and HRQoL domains. The JBI critical appraisal tools for randomized trials and quasi-experimental studies were used to assess the quality and reliability of included studies. Data Analysis A total of 11 studies (n = 9 randomized, 1 nonrandomized control, and 1 quasi-experimental) were included. All studies investigated HRQoL among patients with breast cancer who were following various dietary interventions with different nutritional approaches and objectives. The results varied depending on the diets provided and the HRQoL measured. Conclusions This systematic review shows that evidence remains limited and heterogeneous, highlighting the need for more rigorous research on dietary interventions to improve HRQoL of patients with breast cancer. Nonetheless, offering personalized dietary interventions may improve specific HRQoL-related areas, especially those connected to gastrointestinal health. Systematic Review Registration PROSPERO registration no. CRD420251068900.
Castro-Medina et al. (Wed,) studied this question.