Arachidonic acid is a polyunsaturated fatty acid with four cis double bonds, which are the sources of its flexibility and give it the capacity to react with molecular oxygen. Arachidonic acid is an omega-6 fatty acid. It is one of the essential fatty acids that our body cannot manufacture.
Arachidonic acid is not one of the essential fatty acids. However it does become essential if there is a deficiency in linoleic acid or if there is an inability to convert linoleic acid to arachidonic acid which is required by most mammals. Some mammals lack the ability to—or have a very limited capacity to—convert linoleic acid into arachidonic acid, making it an essential part of their diet. Since little or no arachidonic acid is found in common plants, such animals are obligate carnivores; the cat is a common example.A commercial source of arachidonic acid has been derived, however, from the fungus Mortierella alpina.
Arachidonic acid is present in the membrane of the body's cells, and is a precursor in the production of eicosanoids: the prostaglandins, thromboxanes, prostacyclin and the leukotrienes.
Arachidonic acid is one of the most abundant fatty acids in the brain, and is present in similar quantities to DHA (docosahexaenoic acid). The two account for approximately 20% of its fatty acid content.Like DHA, neurological health is reliant upon sufficient levels of arachidonic acid. Among other things, arachidonic acid helps to maintain hippocampal cell membrane fluidity. It also helps protect the brain from oxidative stress by activating perioxisomal proliferator-activated receptor-y. ARA also activates syntaxin-3 (STX-3), a protein involved in the growth and repair of neurons.Arachidonic acid is also involved in early neurological development. In one study funded by the U.S. National Institute of Child Health and Human Development, infants (18 months) given supplemental arachidonic acid for 17 weeks demonstrated significant improvements in intelligence, as measured by the Mental Development Index (MDI).This effect is further enhanced by the simultaneous supplementation of ARA with DHA. In adults, the disturbed metabolism of ARA may be associated with neurological disorders such as Alzheimer’s Disease and Bipolar Disorder.This may involve significant alterations in the conversion of arachidonic acid to other bioactive molecules (overexpression or disturbances in the ARA enzyme cascade). It is of note that the dietary arachidonic acid consumption is not associated with the onset of Alzheimer's disease, and studies suggest that the supplementation of arachidonic acid during the early stages of this disease may actually be effective in reducing symptoms and slowing the disease progress.Additional studies on the supplementation of arachidonic acid with Alzheimer's are needed.