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Effect of extra virgin olive oil on mild cognitive impairment and dementia in older adults: a systematic review and meta-analysis of clinical trials.

  • 2026-06
  • Clinical nutrition ESPEN 73
    • Victor Cordeiro Simão
    • Tiago Paiva Prudente
    • Arthur De Prado Lopes Oliveira
    • Cesar De Oliveira
    • Erika Aparecida Silveira

Study Design

Type
Meta-Analysis
Sample size
n = 747
Population
older adults with MCI and/or dementia
Methods
comprehensive search across nine databases for RCTs comparing EVOO to control, random-effects meta-analysis, risk of bias assessed using RoB2, GRADE for quality of evidence

Background

Extra virgin olive oil (EVOO) has been investigated as a potential dietary strategy for cognitive health due to its neuroprotective properties. This systematic review and meta-analysis evaluated the potential impact of EVOO as an adjunct intervention for older adults within the spectrum of mild cognitive impairment (MCI) and dementia.

Methods

A comprehensive search was conducted across nine databases for randomized controlled trials (RCTs) that compared EVOO to a control group in older adults with MCI and/or dementia. Statistical analysis used random-effects models to determine mean differences (MD) and standardized mean differences (SMD), with the risk of bias assessed using Cochrane Risk of Bias (RoB2) and quality of evidence assessed using the GRADE tool.

Results

Five studies met the inclusion criteria (n = 747 participants). Meta-analysis showed a significant, albeit preliminary, improvement in global cognitive function scores with EVOO consumption, including the Mini-Mental State Examination (MD = 0.42, 95 % CI = 0.15-0.68; p = 0.002), Clock Drawing Test (MD = 0.47, 95 % CI = 0.15-0.78; p = 0.004), and the Alzheimer's Disease Assessment Scale-Cognitive Subscale (MD = 1.45, 95 % CI = 0.39-2.51; p = 0.007). The overall pooled effect was SMD = 0.29 (95 % CI = 0.18-0.41; p < 0.0001). However, the certainty of evidence was rated as low according to GRADE, and the small number of trials limits the robustness of these findings.

Conclusion

The findings suggest a potential association between EVOO consumption and improvement in global cognitive function among older adults within MCI and dementia. Due to the low certainty of evidence, small sample sizes, and the lack of established clinical significance, these results should be interpreted with caution, and further larger-scale RCTs are required.

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