Exercise and nutritional intervention on improving mental health in older adults: A systematic review and meta-analysis

BACKGROUND: Depression and anxiety are prevalent and burdensome in older adults. Both exercise and nutrition have been individually proven to be beneficial. However, the incremental effects of combined interventions remain underexplored. OBJECTIVE: This research sought to estimate the efficacy of combined exercise + nutrition intervention on depression and anxiety in older individuals, and explicitly compare this intervention with conventional care, exercise alone, or nutrition alone. METHODS: A search was implemented through PubMed, EMBASE, Web of Science, and the Cochrane Library for randomized controlled trials (RCTs) based upon the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines (from their inception to January 6, 2025). The primary outcomes were changes in depression and anxiety scales (pooled effect size as standard mean difference [SMD] with 95% confidence interval [CI]). Heterogeneity was estimated utilizing I² and Q tests. Funnel plots and Egger's regression were implemented when the number of studies was ≥10. Sensitivity analysis utilizing the leave-one-out method and subgroup analysis by follow-up time points were implemented. Methodological quality was estimated utilizing National Institutes of Health Quality Assessment Tool (NIH-QAT). Registration number was PROSPERO. RESULTS: Fourteen RCTs (conducted between 2014 and 2024 in 10 countries) were included. Regarding depression outcomes, combined interventions exhibited marked improvement relative to conventional care at 3 months (SMD = -0.44, 95% CI -0.72 to -0. 16; I² = 53.8%, Qpavle = 0.090) and 6 months (SMD = -0.68, 95% CI -1.06 to -0.30; I² = 0.0%, Qpavle = 0.589). No significant differences were detected relative to nutrition alone (SMD = -0.22, 95% CI -0.57 to 0. 12; I² = 81%, Qpavle = 0.022) or exercise alone (SMD = -0.06, 95% CI -0.20 to 0.07; I² = 10.9%, Qpavle = 0.344). Regarding anxiety outcomes (n = 5), combined interventions did not significantly diminish anxiety scores relative to conventional care (SMD = -0.34, 95% CI -0.86 to 0. 18; I² = 60.9%, Qpavle = 0. 11), nutrition alone (SMD = 0.05, 95% CI -0.39 to 0.49; I² = 0%, Qpavle = 0.88), or exercise alone (SMD = -0.23, 95% CI -0.64 to 0. 17; I² = 0%, Qpavle = 0.347). The NIH-QAT rated 7 studies as good and 7 as fair. Predominant limitations included inadequate allocation concealment, blinding, and reporting. CONCLUSION: Relative to conventional care, exercise + nutrition can improve depression in older individuals in the short term, but show no significant additional benefits for anxiety compared to controls. Nevertheless, no consistent additional strengths were observed over exercise or nutrition alone, suggesting limited or undetected synergistic effect with current evidence. PROSPERO Registration Number: CRD420250649541.