Longer-term effects and underlying mechanisms of dietary intervention strategies on cognitive performance in adults with cognitive impairment

PURPOSE OF REVIEW: As global life expectancy increases, age-related neurodegenerative conditions such as dementia impose an increasing public health and socioeconomic burden. Maintaining a healthy lifestyle, particularly through a healthy diet, may reduce cognitive decline and support cognitive performance in aging populations. Despite increasing interest in dietary interventions as a strategy to enhance cognitive performance, research findings remain inconclusive. This narrative review aims to synthesize evidence on the longer-term effects (published February 2023-October 2024) and underlying mechanisms of dietary intervention strategies on cognitive performance in adults with preexisting cognitive impairment. RECENT FINDINGS: Recent evidence from randomized controlled trials suggests that both single- and multifactor dietary interventions may improve one or more cognitive domains in aging adults with preexisting cognitive impairment. However, variability in intervention types, durations, and participant characteristics limits the ability to draw definitive conclusions. SUMMARY: This review highlights the potential benefits of longer-term dietary interventions on cognitive performance in adults with cognitive impairment. It further integrates emerging mechanistic insights, suggesting that specific dietary components may exert neuroprotective effects primarily by reducing oxidative stress and neuroinflammation, and by enhancing brain vascular function. These mechanisms may promote neuroplasticity through the modulation of neurotrophic signaling pathways. Future research should focus on replicating these findings to validate their efficacy and the underlying mechanisms involved. This is essential for integrating dietary approaches into evidence-based guidelines for promoting long-term cognitive health.