Fish oil and brainpower

Omega-3 fatty acids, particularly those derived from fish oil such as docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA), have been repeatedly linked to brain health. Yet the precise dose–response relationship between omega-3 supplementation and cognitive outcomes in adults remains unsettled. This systematic review and dose-response meta-analysis synthesized evidence from 58 randomized controlled trials published between 2006 and 2023 across North America, Europe, Asia and Oceania. Daily omega-3 doses ranged from 230 to 4,950 mg and interventions lasted from 4 to 160 weeks.

Using standardized mean differences for every 2,000 mg/day increment of omega-3, the authors found notable improvements in several cognitive domains. Primary memory (SMD 0.87), language (SMD 0.98) and visuospatial function (SMD 0.86) benefited most, with moderate to low certainty of evidence by GRADE. Global cognitive abilities also improved (SMD 1.08), although episodic memory showed a U-shaped dose curve—declining at intermediate doses before rising again at higher intakes. Subgroup analyses revealed stronger effects in trials exceeding 26 weeks and among participants with BMI > 25, suggesting that both duration and metabolic status may modulate the cognitive impact of fish oil supplementation.

Given the growing dementia burden—projected to reach 78 million people worldwide by 2030—one might consider tailoring fish oil intake not just for heart health, but also as a strategic measure to preserve cognitive function.