Effects of anthocyanin-rich supplementation on cognition of the cognitively healthy middle-aged and older adults: a systematic review and meta-analysis of randomized controlled trials

Context The prevalence of age-related cognitive decline has been on the rise as the global population age, putting the independence and quality of life of elderly at risk. Anthocyanin, as a subclass of dietary flavonoids, may have a beneficial impact on cognitive outcomes. Objectives To examine the effects of dietary anthocyanin supplementation on cognition of the cognitively healthy middle-aged and older adults. Data Sources PubMed, ScienceDirect, CINAHL, EMBASE, ProQuest and Cochrane databases were searched. Data Extraction and Analysis Thirteen studies were included in this meta-analysis. Anthocyanin-rich supplementation was found to significantly improve the processing speed of the older adults (95%CI 0.08, 0.44; P = 0.004). No significant differences were observed between intervention and control groups on memory, attention, executive function and psychomotor performance. Current neuroimaging studies have found promising effects of anthocyanin supplementation on brain activation and cerebral perfusion. Conclusion Anthocyanin-rich supplementation may preserve cognitive processing speed and neuro-activities in older adults, which improves their daily functioning and quality of life. This review provides useful insights to guide direction and methodological designs for future studies to explore the underlying mechanisms of anthocyanins. Systematic Review and Meta-analysis Registration PROSPERO registration No. CRD42021228007.