Narrative Review of Molecular Mechanisms underpinning the association between Omega-3 Fatty Acids and Cognitive Decline in the Ageing Brain

Abstract

Introduction This review looks at how omega-3 fatty acids (ω-3 FAs) affect brain health and memory in older adults. With the number of people experiencing memory problems, such as mild cognitive impairment (MCI), growing worldwide, this has become an important challenge for healthcare. Omega-3 fatty acids, especially docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA), are long-chain polyunsaturated fatty acids (LC-PUFAs) that play an important role in protecting the brain. Aim This review aims to bring together and explain findings from existing studies to show the molecular pathways through which omega-3 fatty acids support brain function and slow down age-related memory loss. Methods A comprehensive search of primary articles was carried out, including both in vivo and in vitro studies. The focus was on how ω-3 fatty acids influence key brain processes such as neuroinflammation, oxidative stress, and neurotrophic support, the brain’s ability to adapt and learn, and the process of neurogenesis and the function in the growth of new neurons, and the development of disease markers such as β-amyloid plaques in Alzheimer’s disease models.Findings The evidence shows that ω-3 fatty acids are important for protecting cognitive health. They can reduce brain inflammation by lowering pro-inflammatory cytokines, such as IL-1β and IL-6, and they also limit oxidative stress by reducing lipid peroxidation. In addition, omega-3 fatty acids improve synaptic plasticity and stimulate neurogenesis, both of which are essential for memory and learning. Research also suggests that they may reduce harmful changes linked to neurodegenerative diseases, such as the build-up of β-amyloid plaques. Conclusion Overall, the findings suggest that omega-3 fatty acids are crucial to be included in a dietary approach for supporting the ageing brain and lowering the risk of cognitive decline. By acting on several pathways, including inflammation, oxidative stress, and neurotrophic support, they may play a key role in promoting healthy ageing and reducing the burden of memory problems on individuals and healthcare systems, but further research is needed to examine the dose, duration, and long-term effect.