Influence of Various Sugars, Chromium and Other Trace Metals on Serum Cholesterol and Glucose of Rats

Because the feeding of brown sugar or chromium(III) to rats had been found to produce lowered serum cholesterol levels for 11 months, studies were continued to 23 months of age to ascertain long-term effects. In addition an attempt was made to discover other trace factors influencing cholesterol and glucose metabolism. Groups of rats were fed a torula yeast, sucrose and lard diet, with refined white sugar, dark brown sugar or raw sugar. The diet contained 0.08, 0.16 and 0.14 µg/g chromium, respectively, dry weight. One group fed white sugar was given 5 ppm chromium in drinking water, and all were given the other essential trace metals. A standard diet of rye, milk and corn oil was fed to other groups of rats, with or without chromium in water, and with cadmium, nickel and molybdenum. The feeding of white sugar plus chromium, brown sugar or raw sugar retarded the rise of serum cholesterol with age characteristic of chromium deficiency. The feeding of brown sugar lowered fasting serum glucose levels up to 11 months of age but not thereafter in females; in males the level rose after 11 months but did not rise to the levels of the white sugar group. Chromium was hyperglycemic with age, whereas the feeding of brown sugar to male rats was accompanied by lesser elevations at older ages, and raw sugar had minimal effects in both sexes. In rats fed the starch diet, the addition of 5 ppm chromium usually resulted in depression of serum cholesterol and glucose levels, the addition of 50 ppm cadmium had no consistent effects, and the feeding of 50 ppm molybdenum alone without other trace elements resulted in effects on cholesterol similar to those of chromium. The torula yeast diet contained little vitamin E, and neurological symptoms of vitamin E deficiency occurred in all animals fed this diet for 18 to 24 months.