Omega-3 supplementation increases omega-3 fatty acids in lipid compartments that can be taken up by the brain independent of APOE genotype status: A secondary analysis from a randomised controlled trial1

Background: Omega-3 fatty acid (OM3) intake is associated with a lower risk of developing Alzheimer’s disease, but individuals carrying the ɛ4 allele of apolipoprotein E (APOE4) might not benefit from this prevention strategy. Indeed, they might have lower OM3 into plasma free fatty acid (FFA) and lysophosphatidylcholine (LPC) compartments, the two forms the brain can take-in. Objective: To evaluate the docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA) concentrations in the FFA and LPC pre- and post OM3 supplementation in APOE4 carriers and non-carriers. BDesign: Plasma samples from 25 APOE4 carriers and non-carriers before and six months after receiving 2.5 g/d DHA+EPA daily were analyzed. DHA and EPA concentrations in the LPC, and FFA were compared by supplementation and genotype. A secondary analysis investigated the interaction between body mass index (BMI) and APOE genotype status. Results: There was no genotype x supplement interaction nor a genotype effect on LPC and FFA. However, there was a supplement effect where OM3 increased in all lipid compartment by <  1-fold to 4-fold. Individuals with a low BMI had higher OM3 increase concentrations in the LPC than those with a high BMI. Conclusions: APOE4 carriers and non-carriers can both benefit from taking an OM3 supplement. However, individuals with a high BMI have lower OM3 increases than those with a lower BMI.