The 5th Symposium on Nutrition for the Ageing Brain, held on 6–7 June 2025 in Chania, Crete (Greece), brought together leading researchers and professionals to review the growing body of evidence on how nutrients, food, and dietary patterns influence brain health throughout ageing. With a strong scientific programme and vibrant discussions, the event aimed to foster knowledge exchange and stimulate collaboration in this critical and rapidly evolving field. The first workshop on Nutrition for the ageing Brain took place in 2014. It then grew and became a well-attended symposium, attracting up to over 100 delegates from academia, industry, and public institutions. Previous editions of the symposium have led to peer-reviewed publications in Ageing Research Reviews: · Nutrition for the Ageing Brain: Towards Evidence of an Optimal Diet (2016 edition) - Read here · Nutrition for the Ageing Brain: Moving Towards Clinical Applications (2018 edition) - Read here The 5th edition of the symposium addressed six key themes: · Nutrition, Diet and Immune Function · Biomarkers of Cognitive Ageing and Nutrition · Nutritional Interventions for Frailty, Sarcopenia, and Cognitive Function · Nutrition, Dental Health, Oral Microbiome, and Cognition: Exploring the Connections · Nutrition in old age for mental health, with a focus on brain plasticity, cognition and mood disorders · The Intersection of Sex, Nutrition, and Socioeconomic Inequalities, and their implication for health in older age In 2025, the symposium welcomed 77 participants, hosted 21 speakers from 9 countries, and received 31 abstract submissions. These numbers highlight the international interest and engagement in advancing our understanding of brain ageing through the lens of nutrition science. Most abstracts submitted were presented as posters during the symposium and are curated in the present abstract proceedings. This event would not have been possible without the dedication and scientific leadership of the Organising Committee members, who also reviewed and rated the abstracts accepted for this edition: · Prof. Louise Dye, University of Sheffield (UK) · Dr. Piril Hepsomali, University of Reading (UK) · Dr. Sandrine Thuret, King’s College London (UK) · Prof. Wim Vanden Berghe, University of Antwerp (BE) · Dr. David Vauzour, University of East Anglia (UK) · Dr. Nate Matusheski, Haleon (CH) · Dr. Tomasz Rudka, Nutricia (NL) We are grateful to all contributors—organising committee, speakers, poster presenters, and attendees—for making this edition a success. We hope this collection of abstracts will serve as a valuable resource for advancing research and collaboration in the field of nutrition and brain health.