👤 M Emam

Research suggests varying effects of fatty acids on cognitive function and brain structure in neurocognitive disorders, but inconsistent findings call for further investigation and advanced neuroimaging techniques. This study investigated the relationship between serum fatty acid levels (omega-3 PUFAs, omega-6 PUFAs, omega-6:omega-3 ratio, MUFAs, and SFAs) and temporal lobe volume in cognitively normal (CN) individuals, those with mild cognitive impairment (MCI), and those with Alzheimer's disease (AD). The results indicated that, as expected, there was a significant difference in temporal lobe volumes (p < 0.001), with the AD group showing more pronounced reductions in volume compared to both the CN and MCI groups. Unexpectedly, higher plasma omega-3 PUFA levels were associated with reduced temporal lobe volume (β = - 0.31, p = 0.021), and a lower omega-6:omega-3 ratio was also associated with diminished temporal lobe volume (β = 0.26, p = 0.039), both observed only in the AD group, after adjustment for age, gender, education, and APOE ε4 allele status as potential confounders. No significant associations were observed for any lipids with temporal lobe volumes in the CN or MCI groups. Interestingly, the only significant association observed between fatty acids and cognitive function was in the CN group, where higher MUFAs and SFAs were both associated with worse cognitive scores. In short, higher omega-3 PUFA levels and a lower omega-6:omega-3 ratio were associated with reduced temporal lobe volume in Alzheimer's patients not using fatty acid supplements. Notably, this observational cross-sectional study cannot establish causality and should be interpreted cautiously, as the findings may be influenced by residual confounding, non-fasting sampling, potential reverse causality, lack of detailed dietary and longitudinal data, and methodological constraints including limited lipid characterization and region-specific morphometric analysis. Further research is needed to confirm these findings and investigate potential mechanisms. Show less

Patients with Alzheimer's disease (AD) demonstrate brain mitochondrial dysfunction and energy deficiency that are closely associated with cognitive impairment. Cytochrome c oxidase (CCO), also known as mitochondrial complex IV, is the terminal enzyme in mitochondrial electron transport chain (ETC). Consistent with the pivotal role of CCO in mitochondrial bioenergetics and high demand for energy to sustain neuronal function, CCO dysfunction has been linked to neurological disorders including AD. However, it remains unclear whether mitochondrial CCO dysfunction represents an adaptive response to AD-associated toxic molecules versus a Show less