898 XIV. INTUTRITIONAL VALUE OF FATS 



cant differences, however, were observed in other criteria of potassium 

 deficiency. 



Davis and Dubos^^^ demonstrated that serum albumin has the ability 

 to bind oleic acid in the ratio of 9:1. A fat embolism developed in dogs 

 when the amounts injected exceeded this protective range. ^''^ Thus, 

 Jefferson and Necheles'-^" reported that oleic acid does not produce a mas- 

 sive edema of the lungs by embolism but by toxic effects on the lung capil- 

 laries. Both fatty acids and soaps are considered to be equally deleterious. 

 Li and Freeman'-'^ reported that rats exposed to benzene and maintained 

 on a high-fat diet manifested a greater incidence of leucopenia than did 

 control groups, irrespective of the protein content of the diet. Horhck, 

 Katz, and Stamler-" stated that, in the case of white Leghorn cockerels 

 fed a diet of chick starter mash containing 5% of crude fat, the incidence 

 of arteriosclerotic lesions was greater than in control tests in which the 

 fat content was reduced to 0.3% by alcohol-ether extraction, but the 

 ration was supplemented with vitamins A, B, D, and E. However, 

 variations other than the level of fat may be responsible for these diff- 

 erences. 



Certain natural fats may in some cases be toxic to animals if consumed 

 in sufficient amounts. Horse fat may be in this category when it con- 

 tains large amounts of linolenic acid. Lalor and co-workers"* are of the 

 opinion that the disease "yellow fat" in the mink may be the result of the 

 relatively high trienoic acid content in the horse fat which these animals 

 were fed; the trienoic acid was found to be present to the extent of 16%. 

 A condition resembling "yellow fat" could be produced in the mink by 

 feeding 3% linolenic acid in the form of raw linseed oil to these animals. 

 It was noted that a-tocopherol exerted a protective action against this 

 condition. 



3. Factors Altering the Nutritional Value of Fats and Oils 



(i) Comparison of the Nutritional Value of Fats and Oils Based upon 



Composition 



For a discussion of the role of the essential fatty acids, see Chapter XIII 

 of this volume. 

 a. Fat-Soluble Vitamin Content, (a) Vitamins A and Carotene. Vita- 



2'5 N. C. Jefferson and H. Necheles, Proc. Soc. Exptl. Biol. Med., 68, 248-250 (1948). 



"6 T. W. Li and S. Freeman, Am. J. Physiol, 1J,5, 158-165 (1945). 



"' L. Horlick, L. N. Katz, and J. Stamler, Am. Heart J., 36, 472 (1948). 



278 R. J. Lalor, W. L. Leaschke, and C. A. Elvehjem, /. Nutrition, ^5, 183-188 (1951). 



