910 XIV. NUTRITIONAL VALUE OF FATS 



Boer and Jaiiseii/^' which demonstrated the superioritj'^ of butterfat over 

 margarine or over ohve oil, might well be ascribed to the fact that the 

 Swedish investigators used winter butter, from which vaccenic acid, in all 

 probability, was lacking. 



However, a number of reports fail to confirm the fact that \accenic acid 

 has a stimulatoiy effect on groAvth. Although Deuel ct a/.^^" did confirm 

 Ihe fact that rapeseed oil proA'ides a poorer growth than does butterfat or 

 cottonseed oil, no added growth could be demonstrated when vaccenic acid 

 was added to the diet. Similar results were recorded by Euler and co- 

 workers,"*" and by Nath, Barki, Elvehjem, and Hart.'^^'- Sankar and 

 Sarma'*^ also concluded that neither butter nor paddy grass contains 

 unidentified initrients necessary for the rat, and that vaccenic acid has no 

 growth-promoting properties for this species. In fact, Boer and collabora- 

 tors'*''^ have retracted their earlier statement that vaccenic acid has specific 

 nutritional properties. 



12-()ctadecenoic acid, which has physical properties similar to those of 

 vaccenic acid, and which might well have been mistaken for it, was tested 

 by the Deuel group for specific growth-promoting activity, and was found 

 to be compk'tely inactive. -^'^ Even if butterfat could be shown to have a 

 growth-promoting activity superior to that of other animal fats or vegetable 

 fats, it appears definite that neither vaccenic aciti nor 12-octadecenoic acid 

 could account for it. 



(b) Relative Nutritional Value as Based upon Pregnancy and Lactation 

 Tests. As stated earlier, pregnancy and lactation provide successively 

 more critical indices of mitritional value than does growth. It has already 

 been estabhshed that adequate lactation and survival of the young rat 

 require the presence of definite amounts of essential fattj' acids. ^'^ It would 

 be expected therefore that if the importance of fat in pregnancy and lacta- 

 tion were largely or entirely to be ascribed to the presence of EFA, vege- 

 table oils and margarine fat would function equally well or even better 

 than butterfat as a luitritional reciuirement under these conditions. It has 

 been reported from the laboratory of the author^^^ that a number of dif- 

 ferent vegetable oils, a \egetable margarine fat, and butterfat are equally 



"> J. Boer and B. C. P. Jansen, Arch, neerland. physiol., 26, 1-177 (1942); Chem. 

 Zenlr., 194£, I, 20\2 2m:i. 



3« H. Nath, V. H. Barki, ('. A. l^lvclijcm, and K. B. Hart, ./. NiUrilio7i, 36, 761-772 

 (1948). 



"3 D. V. S. Sankar and P. S. Sarma, J. Set. lad. Research (India), f), B, No. 7, 170-173 

 (1950). 



"* J. Boer, E. H. Uroot, and B. C. P. Jansen, Voeding, 9, 00-62 (1948); Chem. Absl., 

 4^,7847(1948). 



"* H. J. Dcuol, Jr., 1-:. .Movitt, and L. F. Hallman, /. Nairilion, 27, 509-513 (1944). 



