Effect of milk and dairy intake on cognitive function in older adults: a systematic review and meta-analysis

TL;DR

This study finds that milk and dairy intake may improve cognitive function in older adults, particularly through randomized trials.

Contribution

The study provides novel evidence from randomized controlled trials supporting dairy's cognitive benefits in older adults.

Findings

Randomized trials showed significant improvements in global cognition, memory, and processing speed with dairy intake.

Fermented and fortified dairy products were associated with moderate to high certainty of cognitive benefits.

Observational studies did not show a significant positive effect of dairy on cognitive function.

Abstract

Cognitive aging represents a growing challenge for global public health. Nutrition could have a beneficial effect in preserving cognitive function, and dairy products have been proposed as neuroprotective due to their nutrient density and bioactive compounds. In this systematic review and meta-analysis, we evaluated the association between milk and dairy product intake and cognitive function in older adults.

The systematic search was conducted in PubMed, Scopus, LILACS, and Google Scholar through 9 August 2025, including randomized controlled trials (RCT) and observational studies evaluating dairy intake versus low or no intake in adults aged ≥60 years. Meta-analysis were conducted using a random-effects model, and methodological quality was assessed using RoB 2.0 (Risk of Bias), ROBINS-I (Risk Of Bias in Non-randomized Studies), and GRADE (Grading of Recommendations Assessment, Development and Evaluation).

22 studies were included (11 RCT, 11 observational studies; n = 47.100), of which 5 RCT (n = 369) and 5 observational (n = 5.302) studies were analyzed by meta-analysis. RCT revealed significant positive effects on global cognition [Standardized Mean Difference -SMD-) = 0.45; 95%CI: 0.30–0.60], memory, and processing speed. This effect was associated in fermented and fortified products, with moderate to high certainty. In observational studies no positive effect emerged (Odds Ratio [OR] = 0.95 95%CI: 0.89–1.02).

Our findings support the potential of dairy intake as a nutritional strategy to preserve cognitive function in older adults, with implications for clinical practice, public health, and food policy design.

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