Background With aging population, the prevalence of neurodegenerative diseases, particularly Alzheimer's disease (AD) and Parkinson's disease (PD), is on the rise. Numerous studies have found that blueberries, rich in polyphenols, have promising neuroprotective effects, but the underlying mechanisms remain unclear. Objective This review summarizes the neuroprotective mechanisms and potential effects of blueberry polyphenols in AD and PD based on in vitro , in vivo , preclinical, and clinical studies. Key findings Blueberries exert multi-targeted effects by reducing oxidative stress (activation of the Nrf2/MAPK pathway), suppressing neuroinflammation (inhibiting microglial activity), and enhancing neuroplasticity (upregulation of the ERK/CREB/BDNF pathway). In preclinical studies, these mechanisms reduce Aβ deposition and tau tangles in AD models and protect dopaminergic neurons in PD models. Limited clinical trials have found that blueberry supplementation can improve executive function, memory, and processing speed in older adults with cognitive decline. Conclusion Blueberries show potential as an early dietary intervention strategy for AD and PD. However, current clinical trials lack sufficient understanding of the bioavailability of blueberry's active components, interindividual metabolic differences, and specific targets of action. Future research should include larger-scale, long-term early intervention trials.
Chen et al. (2026) studied this question.