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

Introduction: 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. Methods: 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). Results: 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). Conclusion: 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.