858 XIV. NUTRITIONAL VALUE OF FATS 



the effects of hyperthyroidism, the most important are suppression of 

 growth and an increased basal metabohsm, together with an augmented 

 heart rate, which is proportional to the metabolic effect. 



Fat has been shown to be the food which has the greatest beneficial 

 effect in cases of hyperthyroidism. Abelin and his co-workers^ ^""^^ were 

 the first to note this effect. These workers reported that the high-fat 

 diet counteracted the increased metabolic rate and likewise prevented the 

 rapid reduction of liver glycogen which normally follows the administra- 

 tion of desiccated thyroid. The beneficial effect of fat in hyperthyroidism 

 has been confirmed by a number of workers.^^"''" Although most of the 

 experimental evidence was obtained on rats, Berg^^ corroborated the fact 

 that dietary fat causes a reduction in the basal metabolic rate following 

 hyperthyroidism in dogs, as well. 



There is some question as to whether the beneficial effects of fat in 

 hyperthyroidism are due to the fat per se or to the essential fatty acids 

 which it contains. Guerra^- correlated the protective effect of fat with 

 its unsaturation; Keeser^' reported that the unessential sodium oleate, 

 which is also unsaturated, is likewise able to prevent the increase in me- 

 tabolism. On the other hand, Zain^^-'^^ observed that linoleic acid, but 

 not stearic acid, prevented the loss of liver glycogen which occurred after 

 the injection of massive doses of the thyroid hormone. However, oleic 

 acid had an intermediate effect, while it should respond in an entirely 

 negative manner if the action of fat were dependent exclusively upon the 

 essential fatty acid content. It is also possible that the negative effect 



6' I. Abelin, Klin. Wochschr., 5, 367 (1926). 



62 I. Abelin, M. Knuchel, and W. Spichtin, Biochcm. Z., 228, 189-210 (1930). 



63 I. Abelin, Biochem. Z., 228, 211-232 (1930). 



" I. Abelin and P. Kursteiner, Biochem. Z., 198, 19-46 (1928). 



66 F. Hoffman, E. J. Huffman, and J. Talesnik, Rev. rned. chile, 73, 393-394 (1945). 



66 E. Munoz. Ortiz, Acci6n de la tiroxina sohre la cuanlia de la tnetabolismo en ratas 

 sometidas a dietas ricas en grasa y relativamente probres en colina. Tesis Cirjuano-Dentista 

 Univ. de Chile, Inst. Fisiol. (1944). 



6^ W. Spalloni Cialdea, Influencia de dietas grasas sobre la elevacidn del consumo de 

 oxigeno en ratas tradadas con tiroxina. Tesis. Quimico Farmaceutico Univ. de Chile, 

 Inst. Fisiol. (1945). 



68 S. M. Greenberg and H. J. Deuel, Jr., J. Nutrition, 42, 279-284 (1950). 



69 B. H. Ershoff, Metabolism, 2, 175-181 (1953). 



™ B. Kennelly and L. A. Maynard, J. Nutrition, 49, 599-608 (1953). 



" J. Berg, Z. ges. exptl. Med., 93, 143-154 (1934). 



^^ E. Z. Guerra, Accion inhibidora de diversas grasas dieteticas (saturadas y no saturadas) 

 sobre elevacidn del consumo de oxigeno producida por el tiroxina. Tesis Medico-Cirnjano, 

 Univ. de Chile. Inst. Fisiol. (1947). 



" E. Keeser, Klin. Wochschr., 17, 1100-1103 (1938). 



7* H. Zain, Klin. Wochschr., 15, 1722 (1936). 



« H. Zain, Arch, exptl. Pathol. Pharmnkol., 187, 302-323 (1937). 



