Linoleic acid keeps the skin impermeable to water, but to exert other effects the compound must undergo specific metabolism. First step is conversion to gama-linolenic acid by delta-6-desaturation. Gama-linolenic acid is subsequently converted to dihomo-gamma-linolenic acid, which is in turn converted to arachidonic acid.
Arachidonic acid can form prostaglandins and thromboxanes – hormone-like lipids that promote blood clotting, induce inflammation and cause smooth muscle contraction. In alternative pathway it can also form leukotrienes, which are one of the most potent inflammatory agents in the human organism.
The necessity of metabolism is reflected by the increasing potency of each substance in the form of an essential fatty acid, as it moves down the chain from linoleic to arachidonic acid; hence to achieve full range of activities, linoleic acid must be metabolized to other substances. Therefore it can be considered as analogous to provitamines.
In infants, delta-6-desaturase is too immature to provide the desired metabolism of linoleic acid, which is a reason why human milk contains gamma-linoleic acid, dihomo-gamma-linoleic acid and arachidonic acid. In contrast, conventional infant formula milks have only linoleic and alpha-linolenic acid, which can lead to a deficiency state in formula-fed infants.
serving of Spirulina 388 mg