Enhancing Brain Health through Omega Fatty Acids: Ahiflower Oil and Oleic Acid as Novel Plant-Based Nootropic Ingredients Targeting the Microbiome–Gut–Brain Axis

• Neurodegenerative diseases significantly impact global health and mortality. • Ahiflower oil emerges as a plant-based dietary source to enhance brain health. • Gut-brain axis modulation via fatty acids may mitigate neurodegenerative risk. • Omega-3, -6 & -9 synergy regulates neuroinflammation & microbiome balance. • Call for long-term, diverse studies to validate dietary fatty acid impacts. Neurodegenerative disorders are a growing global health concern, prompting interest in dietary factors that may influence the development and progression of conditions such as Alzheimer’s disease, Parkinson’s disease, and other age-related cognitive disorders. This review synthesizes current evidence on the relationships between omega fatty acids, brain health, and the gut-brain axis, with a focus on Ahiflower oil ( Buglossoides arvensis ) and oleic acid (OA; 18:1n-9) as candidate plant-based lipid ingredients for brain health. Experimental and clinical data on the neuroprotective actions of omega-3 and omega-6 polyunsaturated fatty acids are summarized, and proposed synergistic, additive, and antagonistic interactions with monounsaturated fatty acids such as OA are examined. Special attention is given to how these fatty acids influence the MGBA, including effects on microbiome composition and SCFA production. Across the literature, Ahiflower oil and OA show promising anti-inflammatory and neuroprotective effects, but findings also indicate complex interactions among omega-3, omega-6, and omega-9 fatty acids, including competition for metabolic enzymes and potential attenuation of tissue omega-3 enrichment by high OA intake. Overall, the reviewed evidence suggests that increasing omega-3 intake may support neuroprotection most effectively when accompanied by balance intakes of omega-6 and omega-9 fatty acids, and highlights key knowledge gaps that must be addressed before plant-based omega-3 guidelines can be established.