806 XIII. ESSENTIAL FATTY ACTUS 



study by Deuel and associates, "^^ it was noted that not only was the time of 

 depletion appreciably shortened when hydrogenated coconut oil was in- 

 cluded in the EFA-free diet, but also the level at which the body weight of 

 the rats reached a plateau was considerably lower when hydrogenated 

 coconut oil was present in the diet. However, the continued presence of 

 hydrogenated coconut oil in the diet did not appear to alter the growth 

 response to linoleate, although the animals depleted with the hydrogenated 

 coconut oil diet had a greater growth potential than did those depleted on 

 the fat-free regimen. The intensity of the effect with hydrogenated coconut 

 fat varied AVTth the proportion of this foodstuff included in the diet. Thus, 

 the effect of a 15% addition exceeded that of 5%, and a much more pro- 

 nounced effect was noted when the fat was included at the 30% level. On 

 the other hand, Wells and DeueP"*^ found that partially hydrogenated tri- 

 olein did not influence the length of the depletion period or the body 

 weight at which the fat-deficiency syndrome was established. Moreover, 

 triolein did not change in any way the effect of linoleate in providing a 

 gain-in-weight in fat-deficient animals. Finally, triolein has been found 

 by Cheng^^ to have no beneficial or deleterious influence upon the resistance 

 to x-irradiation injury in the rat. It is therefore apparent that hydro- 

 genated coconut oil and partially hydrogenated triolein behave differently 

 in the rat insofar as their relationship to EFA is concerned. It is possible 

 that the effect of the hydrogenated coconut oil may be related to the large 

 proportion of 1 auric acid and shorter chain acids in its molecule, as compared 

 with the more physiologic triolein. 



b. Mineral Oil. Bacon and co-workers ^^^ demonstrated that a fat-de- 

 ficiency syndrome could be precipitated in weanling rats within a relatively 

 short period if mineral oil was incorporated into a fat-low diet. When the 

 level of added mineral oil was less than 5%, the cessation of growth was 

 noted at the same time as in the control tests (at eleven to twelve weeks) ; 

 however, when 7.5% or 10% of mineral oil was included in the regimen fed 

 to the weanling rats, the classical fat-deficiency symptoms appeared within 

 two or three weeks. In addition to growth failure, an increased water 

 consumption was likewise noted. 



Proof that the deficiency produced by the inclusion of mineral oil in the 

 diet is a fat deficiency was based not only upon the typical symptoms which 

 developed but also upon the fact that the inclusion of 50 mg. of linoleate 

 per day in the diet prevented them. Moreover, there was an increased 



"2 A. F. Wells and H. J. Deuel, Jr., Unpublished observations, 195-1. 

 1" E. K. Bacon, S. Lassen, S. M. Greenberg, J. W. Mehl, and H. J. Deuel, Jr., J. 

 Nutrition, 47. 383-398 (1952). 



