Linoleic acid encephalomalacia produced

When samples of the ethyl esters of linoleic and linolenic acids were tested at the 1.6 % level in a vitamin E-free diet with low selenium content, both these fatty acids produced exudative diathesis and gave rise to formation of peroxides in the affected fat tissue, but only linoleic acid produced encephalomalacia. This experiment has been repeated many times with diets containing added selenium so that the exudative diathesis was suppressed. In these cases encephalomalacia was the only symptom it occurred only with linoleic acid, not with linolenic acid. The samples of linolenate tested contained a certain amount of trans-isomers it is not known whether the presence of these isomers played a role in preventii encephalomalacia. It is clear, however, that whereas the acceleration of exudative diathesis is related to polyunsaturation of the dietary fatty acids, the production of encephalomalacia is a more complicated matter depending on the structure of the polyunsaturated fatty acid (Dam et aL., 1958b). 

In later experiments. Dam and S0ndergaard (1962) found that ethyl arachidonate was a much more active encephalomalacia-producing agent than linoleic acid when fed at the 1.5% level. This had previously been expected (Dam et al., 1958b Machlin and Gordon, 1960) from indirect evidence. 

Speculating further on the possible mode of action of linoleic acid, one might assume that the encephalomalacia-producing effect is mediated via... 

The nature of fats capable of producing encephalomalacia in diets with casein as the protein source have been investigated further. In diets containing 30 % of lard, such as those frequently used in our studies, the principal polyunsaturated fatty acid is linoleic (about 1.5% of the diet) accompanied by some linolenic and still less arachidonic acid. 

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