Omega 3 Fatty Acids and White Matter Mediated Cognitive Decline in Older Adults

Abstract

ObjectiveOmega 3 PUFAs may work on vascular pathology mediated cognitive decline, including brain white matter lesions and executive skills. We examined whether PUFAs are associated with cognitive domains (executive function and processing speeds) historically sensitive to the accumulation of white matter hyperintensities (WMH).MethodsThis cohort study of 86 non‐demented subjects used the Trail Making Test Part B to represent executive function and the Digit Symbol test for processing speed. Plasma eicosapentaenoic acid (EPA, 20:5n‐3) and docosahexaenoic acid (DHA, 22:6n‐3) were analyzed using GC and combined to form a PUFA index. WMH burden was measured as the total volume of WMH on MRI. Cognitive change was examined using mixed effects models.ResultsAt baseline, the mean age and MMSE were 86 and 28, respectively. Sixty‐two percent were female, 11% had at least one APOE4 risk allele and mean follow up was 4 years. The PUFA index was associated with a 1‐year delay in executive decline attributable to age after multivariate adjustment (p = 0.01). The significance of this index to executive decline was lost after adding WMH volume to the model (p = 0.89), while WMH remained a strong predictor of executive decline (p = 0.02).InterpretationHigher intake of PUFA may slow the decline in executive function by reducing WMH lesions in people at risk for dementia.