Brain Foods: A Narrative Review of Food Items and Their Impact on Cognition over the Life Course

Background/Objectives: Cognitive function is fundamental to daily life, and nutrition is a key modifiable determinant of brain health across the lifespan. While plant-based "brain foods" have been emphasized, the contributions of animal-sourced foods (ASF) to neurodevelopment and cognitive performance remain underexplored. This review synthesizes current evidence on the effects of both plant- and animal-derived foods on cognitive outcomes from early development through older adulthood. Methods: A narrative review was conducted focusing on eight major categories of brain-supportive foods-dairy, eggs, seafood, lean meat, berries, leafy green vegetables, nuts, and whole grains. Evidence was evaluated across life stages, considering nutrient bioavailability, dietary patterns, and the interplay between structural, socioeconomic, and environmental factors that influence access to these foods. Results: Nutrient-dense foods, including ASF and plant-based sources, support cognitive outcomes across the life course. In early childhood, eggs, meat, and nuts were linked to improved neurodevelopment and reductions in developmental delays, while evidence for seafood and dairy was more mixed. During adolescence and adulthood, berries, walnuts, vegetables, and whole grains were associated with improvements in executive function, verbal reasoning, and mood, with adequate bioavailable protein from ASF remaining important. Among older adults, higher intake of leafy greens, nuts, berries, and moderate seafood consumption correlated with slower cognitive decline and improved memory. Findings were limited by heterogeneous study designs, dietary assessments, and underrepresentation of adolescents and populations in low- and middle-income countries. Conclusions: Both animal-sourced and plant-based brain foods uniquely support cognitive development, maintenance, and resilience. While nutritional needs vary across the life course, strong evidence supporting distinct food-based dietary recommendations for cognitive outcomes at different ages, particularly adolescents, remains limited. Current findings suggest stage-specific associations, particularly during early development, but more longitudinal and experimental research is needed. Expanding rigorous, inclusive research will be critical for informing nutrition policies that support lifelong cognitive health.