The role of D-6 D Enzyme
Linoleic acid, the pre-cursor to GLA, sourced from food, is converted to GLA by the enzyme D-6 desturase. GLA is then rapidly converted to the longer chain omega-6 polyunsaturated fatty acids dihomo-γ-linolenic acid and then desaturated to arachidonic acid and further to even longer chain omega-6 polyunsaturated fatty acids.
Only a small fraction of DGLA is converted to AA in some cell types because of limited activity of Δ5 desaturase.
Inefficiency of D-6 D in people with Multiple Sclerosis
Scientific research has shown that many factors including pathophysiological states such as Multiple Sclerosis, diet and age, reduce the efficiency of the conversion of LA to GLA due to a reduction in the efficiency of the delta-6-desaturase enzyme.
Over a dozen scientific research papers have shown MS Patients having a disturbed n-6 fatty acid metabolism (see scientific research on MediOil website).