Metabolic rates high-carbohydrate diet effect

The protective effect of a protein-free diet on DMN toxicity was studied using liver and kidney slices 332, 447). The rate of metabolism of DMN in liver slices from rats fed a protein-free high-carbohydrate diet was less than half the rate observed with liver slices from controls fed a commercial diet, suggesting that more unmetabolized DMN would reach the kidneys of the rats on the protein-free diet. However, in kidney slices the rates of DMN metabolism were the same for both groups. These observations were correlated with a relatively higher level of DNA binding produced in vivo in the kidneys of the rats on the protein-free diet and to a higher incidence of kidney tumors in these rats compared to controls 176). Hepatic DMN demethylase activity was also diminished in rats fed a low-protein diet 331). 

Any pre-emptive or general metabolic effects of the carbohydrates on teeth have not been well established. The work of Sognnaes (97) with hamsters indicated possible prenatal and pre-emptive effects of high carbohydrate diets. Teeth formed when the hamsters received high carbohydrate diets subsequently showed high rates of decay. Because of the difficulty in establishing controls for such experimentation, the validity of these interpretations is doubtful, and more recent experiments indicate that this supposed effect arises from differences in the inorganic portion of the diets (P5). 

In addition, we know that changing a customary diet to one high in protein and low in carbohydrate in some people, increases the rates of metabolism of drugs such as antipyrine and theophylline, and shifting to an isocaloric diet of low protein-high carbohydrate slows the rates of metabolism of these drugs. However, numerous studies emphasize the considerable individual variability to changes in human diets some people exhibit dramatic effects others exhibit little or no response. 

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