Exercise- and dietary pattern-based lifestyle interventions and neurocognitive function in adults: a Bayesian multilevel network and dose-response meta-analysis

Clinical Snapshot

Key Findings

• P Value: Described as statistically significant; exact p-values or posterior probabilities not reported in abstract

• Effect Size: Overall cognition: SMD = 0.18; Memory: SMD = 0.10; Executive function: SMD = 0.09. Network meta-analysis identified AE_MIND and AE_RT_MED as most beneficial for overall cognition; AE_RT_MIND and AE_RT_MED for memory; AE_RT_CR and AE_MIND for executive function

• Primary Outcome: Combined lifestyle interventions (exercise plus dietary pattern) produced statistically significant but small improvements across all three cognitive domains compared with control/usual care and exercise alone

• Nnt Or Sensitivity: NNT not calculable from SMD data without minimal clinically important difference thresholds for specific cognitive instruments. SMD values of 0.09–0.18 are below the conventional small effect threshold of 0.20, suggesting limited individual-level clinical impact

• Confidence Interval: Bayesian credible intervals not explicitly reported in abstract; described as statistically significant for all three domains

Clinical Application

Combined exercise and dietary interventions are broadly feasible in primary and community care settings. Specific combinations such as aerobic exercise with MIND diet or aerobic plus resistance training with Mediterranean diet are practically implementable. However, the absence of a defined optimal dose, frequency, or duration limits prescriptive specificity. Adherence to combined lifestyle programmes over clinically meaningful timeframes remains a practical challenge In the Australian context, lifestyle interventions for cognitive health align with RACGP guidelines on preventive care and healthy ageing. The MIND and Mediterranean dietary patterns are consistent with Australian Dietary Guidelines principles. Exercise prescription for cognitive benefit is supported by the Australian Physical Activity and Sedentary Behaviour Guidelines (150–300 minutes moderate-intensity aerobic activity per week). No PBS-listed pharmacological agents currently demonstrate equivalent or superior cognitive benefit in healthy adults, making lifestyle interventions a first-line, cost-effective strategy. The Dementia Australia and NHMRC frameworks support multidomain lifestyle approaches. TGA considerations are not directly relevant as these are non-pharmacological interventions. General practitioners and geriatricians should note that effect sizes, while statistically significant, are modest and should be contextualised within shared decision-making conversations about realistic expectations General adult population without restriction to specific cognitive diagnoses. Most applicable to middle-aged and older adults at risk of cognitive decline, though the abstract does not stratify by age or baseline cognitive status. Caution is warranted in extrapolating to populations with established mild cognitive impairment, dementia, or significant neurological comorbidities

Abstract

OBJECTIVE: To systematically review the effects of lifestyle interventions focused on exercise and dietary patterns on neurocognitive function in adults, and to examine their relative effects and dose-response relationships. METHODS: PubMed, Embase, Web of Science, and the Cochrane Library were searched from database inception to March 20, 2026. A total of 23 randomized controlled trials (RCTs) involving 12,286 participants were included. Bayesian multilevel pairwise, network, and dose-response meta-analyses were conducted to evaluate overall cognition, memory, and executive function. RoB 2 and CINeMA were used to assess the credibility of the evidence. RESULTS: Combined interventions yielded small, but statistically significant cognitive benefits (overall cognition: SMD = 0.18; memory: SMD = 0.10; executive function: SMD = 0.09). These benefits were driven primarily by differences between the combined intervention and control or usual care, as well as exercise alone; compared with diet alone, the combined intervention still showed a small advantage for executive function. Network meta-analysis suggested that AE_MIND and AE_RT_MED were more beneficial for overall cognition, AE_RT_MIND and AE_RT_MED for memory, and AE_RT_CR and AE_MIND for executive function. Exploratory dose-response analyses suggested possible curvature in some spline-based models; however, comparison with simpler monotonic specifications did not provide robust evidence for a clinically interpretable non-linear or monotonic dose-response relationship. CONCLUSION: Combined lifestyle interventions may produce statistically significant but modest improvements in cognitive function in adults, with benefits varying across cognitive domains. However, current evidence remains insufficient to support a standardized precision prescription, and high-quality RCTs with long-term follow-up are needed to determine the optimal combinations and dosages.

References

1. 1.Jiao, M., Li, Q., Liang, H., Zhang, B., Li, M., Li, J., Harun, M. T., & Wen, F. (2026). Exercise- and dietary pattern-based lifestyle interventions and neurocognitive function in adults: a Bayesian multilevel network and dose-response meta-analysis. Journal of Neurology. https://doi.org/10.1007/s00415-025-13123-x