Essential Fatty Acids (EFA's) are fundamental to the working of each and every cell in our body, they are components of phospholipids that form the structures of cell membranes. The parent EFA's are Alpha Linolenic Acid (ALA) Omega 3 and Linoleic Acid (LA) Omega 6 which convert in the body to the fatty acids below.
DHA is an Omega 3 fatty acid. The body can produce DHA from the essential fatty acid ALA, this conversion depends on a rate limiting step which varies in efficiency from person to person. It is thought that the conversion is especially efficient in infancy. DHA is found in high concentrations in breast milk and in cold-water, deep dwelling algal-eating fish. The grey matter in the brain and the retina of the eye contains high concentrations of DHA.
EPA is an Omega 3 fatty acid. It has different uses in the body from DHA. EPA can also be made by the body and is a precursor to DHA. EPA plays a role in heart health and is also found in high concentrations in cold-water oily fish that eat algae like mackerel and sardines.
GLA is an Omega 6 fatty acid found in Evening Primrose, Borage and Blackcurrant seeds. The body can produce GLA from the essential fatty acid LA, this conversion depends on a rate limiting step which varies in efficiency from person to person. GLA is not widely available in the diet, it is easily damaged and must be carefully extracted from the small seeds of the Evening Primrose plant to ensure that it is available in its most natural form in food supplements.
AA is an Omega 6 polyunsaturated fatty acid. It is also produced in the body from the plant sourced essential fatty acid LA, although this conversion is restricted. AA is directly available in the diet from poultry, animal organs, meat, seafood and eggs. It is found in especially high concentrations in the brain and muscles and is a fundamental part of the structure of a cell.