Advances in research on omega-3 fatty acids for the prevention and intervention of neurological disorders in older adults: a scoping review

Introduction: Age-related neurological disorders impose a growing clinical and public-health burden. Omega-3 polyunsaturated fatty acids, particularly eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), may influence neuronal membrane function, inflammatory resolution, oxidative balance, and synaptic integrity. Objective: It was to map current evidence on omega-3 fatty acids for the prevention and supportive management of neurological disorders in adults aged 60 years and older. Methods: A scoping-review approach was used to synthesize evidence from clinical trials, cohort and observational studies, systematic reviews, and mechanistic research identified in PubMed, Embase, Web of Science, Scopus, and the Cochrane Library. Evidence was organized by mechanism, population, neurological condition, outcome domain, and methodological feature. Because the purpose was evidence mapping rather than pooled effect estimation, no meta-analysis or statistical sample-size calculation was performed. Results: Mechanistic and observational evidence consistently supports biological plausibility and an association between higher omega-3 exposure and healthier cognitive ageing. Trial findings are heterogeneous. Benefits appear more plausible in cognitively normal individuals or those with early impairment, especially when baseline omega-3 status, dose, treatment duration, disease stage, and genetic susceptibility are considered. Evidence in established Alzheimer disease is generally weak, and Parkinson disease trials remain limited. Conclusions: Omega-3 fatty acids are promising components of multimodal neurological-health strategies, but they should not be presented as established stand-alone treatments. Future trials should be adequately powered, biomarker guided, longer in duration, and standardized in exposure and outcome measurement. Graphical Abstract