Dietary inflammatory index and quality of life in patients with breast cancer: a cross-sectional study

BACKGROUND: Breast cancer survivorship is frequently accompanied by impaired quality of life (QoL). Diet-related systemic inflammation may influence physical, emotional, and psychological well-being, yet evidence linking the inflammatory potential of diet to QoL in women with breast cancer remains limited. METHODS: ) and energy-adjusted DII (E-DII™) were calculated, and QoL was assessed using a five-point Likert scale. Associations of DII and E-DII with QoL were examined using multivariable linear regression with adjustment for potential confounders. Quartile-based analyses and tests for linear trend were also performed. RESULTS: Higher DII scores were associated with lower QoL in adjusted models (β = -0.12; 95% CI: -0.16 to - 0.08; p < 0.001), with a clear linear decline in QoL across increasing DII quartiles (p for trend < 0.001). E-DII was similarly inversely associated with QoL (β = -0.06; 95% CI: -0.11 to - 0.02; p = 0.007), and a consistent trend across E-DII quartiles was observed (p for trend = 0.01). DISCUSSION: Diets with greater pro-inflammatory potential were associated with poorer QoL among women with breast cancer. Although the cross-sectional design precludes causal inference, these findings support the hypothesis that anti-inflammatory dietary strategies may be a relevant target in survivorship care and justify longitudinal and interventional studies to clarify directionality and clinical impact.