Dietary and Nutrition Interventions for Breast Cancer Survivors: An Umbrella Review.

Abstract

Breast cancer is the most common malignancy among women globally, with survival rates improving due to earlier detection and better treatment. As a result, cancer survivors now constitute a growing segment of the population, and addressing their long-term health and well-being is a public health priority. Diet and nutrition represent modifiable factors that may influence recurrence, comorbidities, and quality of life (QoL), yet clear evidence-based guidance remains limited. This umbrella review thus synthesized evidence from published reviews on the effects of dietary and nutrition interventions among breast cancer survivors. Following a prospectively registered protocol in PROSPERO (CRD420251185022), six databases (PubMed, EMBASE, Scopus, Cochrane Library, PsycINFO and CINAHL) were systematically searched for systematic reviews/meta-analyses evaluating dietary or nutrition interventions in adult breast cancer survivors. Eligible reviews reported anthropometric, metabolic, psychosocial, or survival outcomes. Methodological quality was appraised using the AMSTAR-2 tool, and findings were narratively synthesized. Nine systematic reviews encompassing more than 10,000 breast cancer survivors were included. Interventions ranged from general dietary counselling and structured weight-management programmes to Mediterranean-style dietary patterns, dietitian-led primary care, multiple health behaviour change interventions, mobile nutrition apps, and broader lifestyle programmes incorporating diet. Across reviews, interventions consistently improved diet quality and fruit-vegetable intake, produced modest but meaningful reductions in weight, body mass index, and body fat, and enhanced several QoL domains (e.g., fatigue, physical functioning, body image). Higher adherence to Mediterranean-style diets was associated with lower all-cause and non-breast cancer mortality, though certainty was limited by observational designs. However, evidence for long-term maintenance, survival endpoints, and ethnically diverse or low- and middle-income populations remains sparse. Dietary and nutrition interventions, particularly structured, dietitian-supported, and Mediterranean-style approaches, contribute to improved diet quality, sustainable weight control, and enhanced QoL among breast cancer survivors. Integrating nutrition care into survivorship pathways should be the focus of future research.