Dietary factors and cognitive aging: Mapping epidemiological evidence and the role of gut microbiota
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GRAPHICAL ABSTRACT
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PUBLIC SUMMARY
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Healthy dietary patterns have generally been associated with better cognitive health.
Evidence on specific dietary components and cognitive aging offers clues to diverse mechanistic pathways.
Gut microbiota may act as a mediator, moderator, or health indicator in the associations of diet with cognition.
Diet-microbiota-cognition research faces challenges in measurement, methodology, and generalizability.
Further work should clarify causal pathways and personalize dietary strategies for dementia prevention.
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ABSTRACT
Dementia is a growing global health challenge with limited pharmacological treatments. Emerging evidence from randomized controlled trials and prospective cohort studies suggests that healthy dietary patterns may contribute to the prevention or delay of cognitive decline. This review summarizes current evidence on the relations of overall dietary patterns and specific foods and nutrients to cognitive aging, with a particular focus on the potential role of gut microbiota, which is largely shaped by diet. Certain healthy dietary patterns, such as the Mediterranean and the Mediterranean–DASH Intervention for Neurodegenerative Delay (MIND) diets, characterized by specific foods (e.g., vegetables and fruits) and dietary nutrients (e.g., n-3 fatty acids, B vitamins, and carotenoids) have shown potential benefits on cognitive health. However, inconsistencies across study findings necessitate further investigation. We review how the gut microbiota may mediate or moderate the diet-cognition association, or serve as a marker for cognitive health, particularly through mechanisms involving metabolic, immune, and neuroinflammatory pathways. Finally, we highlight key methodological challenges, including variability in exposure assessment, study design, and population heterogeneity, and propose a roadmap for future research, advocating for large-scale, multi-omics studies across diverse populations. These efforts are expected to facilitate the development of precision nutrition strategies for the prevention of cognitive decline and dementia.-
Keywords:
- diet /
- cognitive aging /
- dementia /
- gut microbiota /
- nutritional epidemiology
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REFERENCES
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Chen H., Shen J., Liu X., et al. (2026). Dietary factors and cognitive aging: Mapping epidemiological evidence and the role of gut microbiota. The Innovation Nutrition 1:100030. https://doi.org/10.59717/j.xinn-nutri.2026.100030
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Chen H., Shen J., Liu X., et al. (2026). Dietary factors and cognitive aging: Mapping epidemiological evidence and the role of gut microbiota. The Innovation Nutrition 1:100030. https://doi.org/10.59717/j.xinn-nutri.2026.100030
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Figure 1.
Conceptual framework of hypothesized intermediate processes linking dietary exposures to brain-aging outcomes
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Figure 2.
Evaluating the evidence level of existing literature on associations of major dietary factors with cognitive outcomes based on the NutriGrade* framework
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Figure 3.
Potential roles of the gut microbiome in diet-cognition associations
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Figure 4.
Potential solutions to key challenges and future directions in diet-microbiota-cognition research.
