Dietary bioactive compounds, healthy ageing, and cognition – A focus on polyphenols and the brain

Abstract

Dietary polyphenols are bioactive plant-derived compounds increasingly recognised for their potential to support cognitive health across the lifespan. These compounds, including flavonoids, phenolic acids, stilbenes, and lignans, exert antioxidant, anti-inflammatory, and cell-signalling effects that influence key processes underlying cognition [1]. Emerging evidence suggests that polyphenols contribute to enhanced neurovascular function, modulation of neuronal signalling, and reduction of neuroinflammation, as well as interacting with the gut microbiota via the microbiota–gut–brain axis [2].

Observational studies indicate that higher consumption of polyphenol-rich foods is associated with improved memory and executive function, alongside a reduced risk of cognitive decline and dementia [3,4]. Complementary evidence from the MRC National Survey of Health and Development (NSHD) further demonstrates that adherence to healthy and plant-based dietary patterns is positively associated with cognitive reserve [5]. Additionally, findings from randomised controlled trials and meta-analyses further support modest but significant cognitive benefits, particularly in ageing populations [6].

Despite these promising findings, important challenges remain, including variability in polyphenol bioavailability, inter-individual differences, and limitations in the current evidence base. Well-designed, long-term randomised controlled trials are needed. Overall, dietary polyphenols represent a potentially important modifiable factor for cognitive health, while highlighting key priorities for future research, policy, and public health nutrition.

References

1. Del Rio D, Rodriguez-Mateos A, Spencer JP, Tognolini M, Borges G, Crozier A. Dietary (poly) phenolics in human health: structures, bioavailability, and evidence of protective effects against chronic diseases. Antioxidants & redox signaling. 2013 May;18(14):1818-92.

2. Sbai O, Perrone L, Poucheret P. The Role of Polyphenols on Cognitive Function and Dementia Through Gut–Microbiota–Brain Axis Modulation: A Narrative Review. Nutrients. 2026 May 26;18(11):1697.

3. Devore EE, Grodstein F, van Rooij FJ, Hofman A, Stampfer MJ, Witteman JC, Breteler MM. Dietary antioxidants and long-term risk of dementia. Archives of neurology. 2010 Jul 1;67(7):819-25.

4. Letenneur L, Proust-Lima C, Le Gouge A, Dartigues JF, Barberger-Gateau P. Flavonoid intake and cognitive decline over a 10-year period. American journal of epidemiology. 2007 Jun 15;165(12):1364-71.

5. Cara KC, Scott TM, Jacques PF, Chung M. Associations between healthy and plant-based dietary patterns and cognitive reserve: A cross-sectional analysis of the 1946 British Birth Cohort. Current Developments in Nutrition. 2025 Nov 12:107599.

6. Cheng N, Bell L, Lamport DJ, Williams CM. Dietary flavonoids and human cognition: a meta‐analysis. Molecular nutrition & food research. 2022 Nov;66(21):2100976.

Acknowledgements

We would like to acknowledge Luigi Palla, Catherine Hughes, Martin Kohlmeier, and Melina Jampolis for their important contributions to the NNEdPro Nutrition and Cognition Research Programme and thank Matheus Abrantes for strategic operational support.