It Is Time for an Oil Change: Polyunsaturated Fatty Acids and Human Health

Abstract

Polyunsaturated fatty acids (PUFAs) such as docosahexaneoic acid (DHA) and eicosapentaneoic acid (EPA), play a critical role in a variety of neuronal functions, including facilitating neuronal growth and differentiation, increasing the density of the neuritic network, modulating cell membrane fluidity, regulating intracellular signaling and gene expression, and exhibiting antioxidant characteristics. Dietary DHA is selectively enriched and actively retained in the central nervous system, mainly in synaptic membranes, dendrites, and photoreceptors. In this review, we highlight the myriad roles of PUFAs in brain function and human health. Diets rich in DHA are inversely proportional to cognitive decline and incidence of neurodegenerative disorders. Conversely, diets deficient in DHA impair the proper development of brain and the visual system in children and increase risk of brain disorders in the elderly. Finally, DHA and EPA have been shown to reduce inflammation and may prove to be beneficial in reducing the severity of the SARS-COVID infection.

Figure 1

Mechanism of action of docosahexaenoic acid. Docosahexaenoic acid (DHA) binds to the G protein coupled receptor GPR-40 which leads to the activation of phospholipiase C (PLC), conversion of phosphatidylinositol 4,5-bisphosphate (PIP2) to form diacylglycerol (DAG) and inositol tris phosphate (IP3), which activates the IP3 receptor leading to the release of calcium from ER stores. The increase of intracellular Ca2+ activates protein kinase C (PKC) which leads to synaptogenesis Adapted from Ma et al., 2010, DHA promotes the neuronal differentiation of rat neural stem cells transfected with GPR40 gene, Brain Research, 2010, 1330, 1 – 8.