Effects of anti-inflammatory dietary education on sleep disturbances among patients with breast cancer undergoing chemotherapy: A randomized controlled trial

Purpose: This randomized controlled trial evaluated the effects of anti-inflammatory dietary education on sleep disturbances and inflammatory biomarkers in patients with breast cancer undergoing chemotherapy. Methods: A total of 132 patients with sleep disturbances were randomized to receive either a 12-week anti-inflammatory dietary education program based on the energy-adjusted dietary inflammatory index (E-DII) or usual care. Sleep disturbances were assessed using the Pittsburgh Sleep Quality Index (PSQI) at baseline and at 12 weeks. Additional outcomes included inflammatory biomarkers, E-DII scores, and quality of life (QoL). Treatment effects on continuous outcomes were evaluated using linear mixed-effects models (LMMs) under the intention-to-treat principle. The proportions of participants with sleep disturbance (PSQI ≥ 8) at 12 weeks were compared between groups using a completer analysis. Results: Of the 132 participants, 116 (87.9%) completed the 12-week assessment. In the completer analysis, the proportion of participants with sleep disturbance at 12 weeks was significantly lower in the intervention group than in the control group (49.2% vs. 78.9%, P < 0.001). The intervention group demonstrated greater reductions in PSQI (β = − 2.10; 95% CI: − 3.01, − 1.18; P < 0.001) and E-DII scores (β = − 1.23; 95% CI: − 1.98, − 0.47; P = 0.002) and improved overall QoL (β = 14.07; 95% CI: 8.61, 19.52; P < 0.001). Furthermore, levels of interleukin-1β, interleukin-6, and C-reactive protein were significantly reduced, whereas interleukin-10 increased (all P < 0.05). Conclusion: Anti-inflammatory dietary education reduced sleep disturbances and improved QoL in patients with breast cancer undergoing chemotherapy and was accompanied by favorable changes in inflammatory biomarkers. Trial registration: ChiCTR2500097053. Registered on 11 February 2025. © The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature 2026.