Effect of Whey-Derived Lactopeptide β-Lactolin on Memory in Healthy Adults: An Integrated Analysis of Data from Randomized Controlled Trials

Context: Epidemiological studies have shown that consumption of dairy products reduces the risk of dementia and cognitive decline in older individuals. Tryptophan-tyrosine-related β-lactopeptides and their representative β-lactolin of glycine-threonine-tryptophan-tyrosine tetra-peptide have been identified as agents in dairy products, which improve cognitive function as well as memory function via the activation of the dopaminergic system in a mouse model of amnesia. Previous clinical trials have shown that supplementation with β-lactolin improves memory retrieval in healthy older adults. Specifically, β-lactolin improved the scores in some neuropsychological tests. However, the effects of β-lactolin on memory function have not been clarified. Objectives: The aim of this study was to evaluate the effect of β-lactolin on memory function using statistical methods. Data Sources: We searched the Web of Science, Cochrane Library, and JDream III until November 2021 to identify relevant randomized controlled trials for integrated analysis. Data Synthesis: Three randomized controlled trials evaluating the effect of β-lactolin on memory in healthy adults were selected for the integrated analysis. The results showed that the score of cued recall among the neuropsychological tests in the β-lactolin group was significantly higher than that in the placebo group (g=0.33; 95% CI: 0.10, 0.55). In addition, the total memory score was higher but this difference was not significant (g=0.17; 95% CI: −0.09, 0.43). Conclusions: Taken together, these results suggest that supplementation with β-lactolin improves cued recall in healthy older adults.