DIET AND TUMOR GROWTH 513 



slightly above normal; uric acid and sugar were within normal limits. 

 Cholesterol, fatty acids and total fats are generally increased in the 

 blood in malignancy.'"" 



(7) Diet and Tumor Growth. — In general, any condition that 

 decreases the nutrition of tlic body as a whole, or of the tissue in which 

 a tumor is located, decreases the rate of growth of the tumor, in which 

 respect neoplasms exhibit quite the opposite behavior to infectious 

 processes. Thus, the older the individual the more slowly the tumor 

 usually grows; ligation of the lingual artery retards the growth of 

 cancer of the tongue; repeated pregnancy and lactation delay the 

 progress of cancer in mice,"*^ suggesting that tumor cells have a greater 

 avidity for nutritive elements in the blood than have ordinary somatic 

 cells, but less than the cells of the fetus or of the active mammary gland. 

 Numerous attempts have been made to determine the relation of tumor 

 growth to specific dietary deficiencies. Sweet, Corson- White and 

 Saxon"*- found that rats kept upon a diet deficient in specific amino- 

 acids (lysine), so that body growth did not occur although nutrition 

 was maintained, show a slower growth of implanted tumors than ani- 

 mals on an adequate diet. Rous"*^ obtained similar results with some 

 transplanted tumors, but not with all, nor with spontaneous tumors. 

 Van Alstyne and Beebe*'* found that rats living on casein and lard 

 showed much less growth of inoculated tumors than when lactose was 

 added to the diet. Robertson and Burnett"*^ observed that the addi- 

 tion of cholesterol to the diet increases the rate of growth and the de- 

 velopment of metastases in inoculated rat tumors, which has been 

 corroborated by others. This accelerative action depends on the hy- 

 droxyl radical, although other hydroxy-benzol derivatives do not have 

 this effect."*" The growth-promoting principle of the hypophysis, 

 tetheUn, is also said to stimulate cancer growth. Funk"*^ found 

 greater growth of inoculated sarcoma in fowls given normal diets than 

 in those fed pohshed rice. Benedict and Rahe'*^ supplied vitamines 

 by adding to an otherwise inadequate diet, just enough yeast to keep 

 the rats in fair condition, and found that inoculated tumors grew, 

 although extremely slowly, even when the animal itself could not grow. 

 Evidently tumor cells cannot manufacture substances essential for 

 growth i. e. vitamines. Corson-White*^ states that, generally, 

 vitamine-rich diets favor tumor growth, especially if there is also an 

 abundance of cholesterol. Fraenkel,^° however, observed no stimulat- 

 ing effect from rice polishings or yeast extracts. 



"» Ee Niord et al., Arch. Int. Med., 1920 (25), 32. 



"^ See Maud Slve, Jour. Cancer Res., 1919 (4), 2.5. 



'- Jour. Biol. Chem., 191.3 (15), LSI ; 1915 (21), 311. 



« Jour. Exp. Med., 1914 (20), 433. 



" Jour. Med. Res., 1913 (24), 217. 



** Jour. Exp. Med., 1913 (17), 344. 



^« Jour. Cancer Res., 1918 (3), 75. 



*' Zeit. phvsiol. Chem., 1913 (88), 352. 



^8 Jour. Cancer Res., 1917 (2). 1.59. 



" Penn. Med. Jour., 1919 (22), 348. 



*" Wien. klin. Woch., 1916 (29), 483. 



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