Assessment of the essential fatty acid requirement in gerbils by polyunsaturated fatty acid ratio.

Essential fatty acid status in the gerbil was assessed using the ratio of 20:3 omega 9 (5,8,11-eicosatrienoic acid) to 20:4 omega 6 (arachidonic acid) derived from liver phospholipid. Both a fat-free diet and a diet containing 20% hydrogenated coconut oil produced an essential fatty acid deficiency. The minimum requirement for 18:2 omega 6 (linoleic acid) in the gerbil, like that in the rat, was estimated at 1% kcal of the diet when graded levels of safflower oil were added to a purified diet containing hydrogenated coconut oil. Dietary cholesterol did not affect the minimum requirement, but accentuated the triene:tetraene ratio when the dietary linoleate level was below the requirement.