Brain uptake and utilization of fatty acids, lipids & lipoproteins: recommendations for future research

A major goal of the second International Workshop on "Brain Uptake and Utilization of Fatty Acids, Lipids and Lipoproteins: Application to Neurological Disorders" was the identification of important future research areas that would lead to accelerated and systematic progress in the field. Major themes identified for future research include the following: (1) Rigorous research protocols for fatty acid (FA) studies should be established to overcome errors introduced by small differences in chain length and degree of unsaturation. (2) Using cellular integration models consisting of endothelial cells, astrocytes, and neurons, investigation of functional lipidomics, cell-specific signaling by lipids, and nutritional considerations should be undertaken. (3) Educational programs should be undertaken for women of childbearing age on the health benefits of omega3 long chain (LC) polyunsaturated fatty acids (PUFA) from fish consumption vs risks of mercury in fish. (4) Studies of the "flip-flop" model of passive diffusion should be extended to include other quantitative measures, such as the sizes of different fatty acid pools. (5) Investigations to establish physiologic roles and concentrations of omega3 LC-PUFA in various compartments of the brain should be undertaken. (6) Further studies should be carried out to illuminate the role and behavior of tight junctions in the microvascular endothelium of the blood-brain barrier and astrocytes, with emphasis on developing new LC-PUFA and lipid-based carriers of biomolecules across this barrier. (7) Roles and localization of very low density lipoproteins, low density lipoprotein (LDL), and the LDL receptor in the brain and their interactions with omega3 LC-PUFA, cholesterol, apolipoprotein E1-4, and their derivatives in Alzheimer's disease (AD) should be assessed. (8) Investigation of intraneuronal synthesis of DHA and its effects on signal transduction, apoptosis, and neurite growth stimulation should be undertaken. (9) Nutrition-based behavioral affects of EPA and DHA, particularly with respect to the omega6:omega3 FA ratio, gene regulation, neurodevelopment, and conversion to bioactive molecules by cyclooxygenases (COX) and lipoxygenase, should be explored. (10) Further assessment of brain lipid metabolism and neurodevelopment should be performed in DHA-deficient rodent models, including the use of imaging techniques. (11) Potential toxic effects of COX overexpression and the possible consequences of DHA over-supplementation in various neurological and neurodevelopmental disorders should be characterized. (12) The relationship between LC-PUFA, stroke, and AD should be clarified, and neurogenetic metabolic diseases that could benefit from supplementation with omega3 LC-PUFA such as DHA should be identified.