Nutritional interventions for late-life depression: evidence, mechanisms, and clinical assessment tools

Late-life depression (LLD) is common and disabling in older adults, and current pharmacological or invasive treatments are often limited by comorbidity and tolerability. Nutrition is a modifiable target with potential clinical value. This review examines the epidemiological association between nutritional status and LLD. It synthesizes evidence on essential nutrients and dietary patterns, discusses potential underlying mechanisms, and evaluates the clinical utility of nutritional assessment tools-such as the Geriatric Nutritional Risk Index (GNRI), the Mini Nutritional Assessment (MNA) combined with the Geriatric Depression Scale (GDS), and the Comprehensive Geriatric Assessment (CGA)-for identification and intervention. Overall, malnutrition and nutritional risk are consistently associated with greater depressive symptom burden in later life, and emerging data suggest that chrono-nutrition (particularly higher energy intake at breakfast) may be a relevant, under-recognized modifier of depression risk. Mechanistically, nutrition may influence LLD through neuroinflammation, neuroplasticity, gut-brain axis signaling, and oxidative/mitochondrial pathways. Pattern-based strategies appear most actionable: higher adherence to Mediterranean-type diets and Mediterranean-Dietary Approaches to Stop Hypertension Intervention for Neurodegenerative Delay (MIND) diets is generally linked to fewer depressive symptoms, whereas Western/processed-food patterns are generally associated with adverse outcomes; for plant-based approaches, dietary quality is critical. For nutrient-focused interventions, effects remain heterogeneous; benefits may depend on baseline deficiency, inflammatory status, and for omega-3, the eicosapentaenoic acid (EPA) to docosahexaenoic acid (DHA) ratio and dose. For clinical implementation, we highlight an assessment-to-intervention workflow integrating GNRI-based rapid stratification, MNA plus GDS screening, and CGA-guided multidisciplinary management for frail or complex patients. Future research should prioritize adequately powered randomized controlled trials (RCTs) with standardized protocols, biomarker-informed and genotype-aware stratification, and interdisciplinary translation to optimize nutrition-based prevention and comprehensive management of LLD.