FACTORS ALTERING NUTRITIONAL VALUE 923 



acid deficiency, but in a much more severe form than that ordinarily pro- 

 ckiced by the exclusion of essential fatty acids from the diet. Holman and 

 Greenberg"^ reported that ethyl linoleate, either fresh, slightly oxidized, or 

 fed with benzoyl peroxide, cured fat deficiency symptoms and decreased 

 water consumption in fat-deficient rats. Ethyl linoleate hydroperoxide, 

 thei-mally decomposed ethyl linoleate hydroperoxide, reduced ethyl 

 linoleate hydroperoxide, and conjugated ethyl linoleate, were all found to 

 be inefTective in curing the fat deficiency symptoms or in decreasing water 

 consumption. However, when all of the essential nutrients w^ere fed 

 separately from the rancid fat, no toxic symptoms deA^eloped in rats.""* 

 Thus Kaunitz, Johnson, and Slanetz"^ reported that the inclusion of 10% 

 of rancid lard in the purified rat diet did not result in toxic symptoms under 

 these conditions, although the rats were 5% lighter than the control ani- 

 mals. However, when riboflavin was withdrawn, a severe reduction of 

 growth and food intake occurred. A less pronounced effect was observed 

 when mildly rancid lard was fed, or when fresh fat was given. It is therefore 

 apparent that rancidity accentuates the signs of riboflavin deficiency, 

 which may well be due to a reduction of the riboflavin made available by 

 the intestinal flora. It is also believed by these workers that rancid lard 

 increases the requirements for various other essential components."^ 

 Others who have reported on the destruction of vitamins and of other essen- 

 tial dietary components by rancid fats are Quackenbush,"" Barnes and co- 

 workers,"^ and Grench"' and Barnes et al.^"^^ found that the ingestion of 

 highly rancid fat by rats resulted in oxidative destruction of the biotin 

 synthesized in the intestine. 



Gyorgy and co-w^orkers"^ observed that, when diets containing linoleic 

 acid and cod-liver oil became rancid, they were very toxic for rats. The 

 animals lost weight, and developed secondary anemia and leucopenia, and 

 were subject to pediculosis. However, these symptoms could be prevented 

 by the daily addition of yeast to the diet. The toxicity was apparently due 

 to oxidation of the unsaturated acid. It was also found that linoleic acid 

 present in the diet was almost completely destroyed by oxidation on stand- 

 ing at room temperature for three to four weeks. 



3" R. T. Holman and S. I. Greenberg, Federation Proc, 12, 219 (1953). 



''" H. Kaunitz, R. E. Johnson, and C. A. Slanetz, J. Nutrition, 46, 151-159 (1952). 



"5 F. W. Quackenbush, Oil & Soap, 22, 336-338 (1945). 



"« R. H. Barnes, M. Clausen, I. I Rusoff, H. T. Hanson, M. E. Swendseid, and G. O. 

 Burr, Arch. sci. physioL, 2, 313-328 (1948). 



"'J. M. Grench, Ph.D. Thesis, Univ. Birmingham Med. School (England), 1949; 

 cited bv S. M. Greenberg and A. C. Frazer, J. Nutrition, 50, 421-440 (1953), p. 421. 



3"8 P. Gyorgv, R. Tomarelli, R. P. Ostergard, and J. B. Brown, ./. Exptl. Med., 76, 

 413-420(1942). 



