Sheldon Reiser

The severity of copper deficiency in rats is determined by the type of dietary carbohydrate.

Abstract The purpose of this investigation was to study the interaction between copper and dietary carbohydrates on clinical and enzymatic indices associated with copper deficiency. Copper deficiency was produced in rats by feeding diets adequate in all nutrients including selenium and chromium, but marginal in copper (1.2 μg/g diet) containing 62% of either starch, fructose, or glucose. During the fifth week, the fructose of the copper-deficient diet (20 rats) was replaced by either starch (10 rats) or by glucose (10 rats). The experiment was terminated after 11 weeks. Copper deficiency in rats fed fructose significantly lowered body weight and hematocrit, but increased liver weight, blood urea nitrogen, ammonia, cholesterol, and triglycerides when compared to rats fed starch or glucose. The copper metalloenzyme, superoxide dismutase, the selenoenzyme, glutathione peroxidase, and hepatic ATP were decreased in the copper-deficient rats fed fructose as compared to copper-deficient rats fed starch or glucose. These results indicate that fructose may be the dietary component which has a deleterious effect on copper and selenium status. Changing the type of dietary carbohydrate in copper-deficient rats from fructose to either starch or glucose ameliorated the severity of the deficiency. The protective effects were more pronounced with starch than with glucose.

Interaction between dietary carbohydrate and copper nutriture on lipid peroxidation in rat tissues.

The effects of the interactions between dietary carbohydrates and copper deficiency on superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) activities and their roles in peroxidative pathways were investigated. Weanling rats were fed diets deficient in copper and containing either 62% starch, fructose, or glucose. Decreased activity of SOD was noted in all rats fed the copper-deficient diets regardless of the nature of dietary carbohydrate. However, the decreased activity was more pronouced in rats fed fructose. Feeding the fructose diets decreased the activity of GSH-Px by 25 and 50% in the copper-supplemented and copper-deficient rats, respectively, compared to enzyme activities in rats fed similar diets containing either starch or glucose. The decreased SOD and GSH-Px activities in rats fed the fructose diet deficient in copper were associated with increased tissue per-oxidation and decreased hepatic adenosine triphosphate (ATP). When the fructose in the diet of copper-deficient rats was replaced with either starch or glucose, tissue SOD and GSH-Px activities were increased and these increases in enzyme activity were associated with a tendency toward reduced mitochondrial peroxidation when compared to the corre-sponding values for rats fed fructose throughout the experiment Dietary fructose aggrevated the symptoms associated with copper deficiency, but starch or glucose ameliorated them. The protective effects were more pronounced with starch than with glucose.

Serum uric acid, inorganic phosphorus, and glutamic-oxalacetic transaminase and blood pressure in carbohydrate-sensitive adults consuming three different levels of sucrose.

12 men and 12 women, classified as carbohydrate-sensitive on the basis of an exaggerated insulin response to a sucrose load, consumed diets containing either 5, 18, or 33% sucrose in a crossover design. The diets simulated the average American diet and consisted of identical natural and processed foods with the exception of a patty. The patty provided the experimental levels of sucrose; the difference was made up by starch. Each level of sucrose was consumed for a 6-week period. Subject body weights were maintained. Fasting serum uric acid and inorganic phosphorus increased as the level of dietary sucrose increased. Diastolic blood pressure was significantly higher when subjects were on the 33% sucrose diet as compared to the 5 and 18% diets. Serum glutamic-oxalacetic transaminase was not affected by diet. In tolerance tests after a sucrose load (2 g/kg body weight), the uric acid response was higher after the 18 and 33% sucrose diets than after the 5% sucrose diet. Serum inorganic phosphorus, which increased significantly with each level of dietary sucrose, decreased following the sucrose load. These results indicate that carbohydrate-sensitive individuals may be affected adversely by the level of sucrose commonly found in the Westernized diet. Since elevated serum uric acid and blood pressure have been identified as risk factors in degenerative diseases, this study suggests that carbohydrate-sensitive individuals should limit their sucrose consumption.

Dietary fructose exacerbates the cardiac abnormalities of copper deficiency in rats.

Copper deficiency has been shown to result in severe cardiovascular lesions in several species of animals. The principal carbohydrate in the copper-deficient diet most often used with rats is sucrose, which is known to have adverse effects on carbohydrate and lipid metabolism and thus may contribute to cardiovascular disorders. These observations prompted experiments in which starch and fructose were substituted for sucrose in a copper-deficient diet, to see if the effects of the copper deficiency might be modified. In the hearts from rats fed copper-deficient diets with fructose or sucrose, there was marked, mostly ventricular hypertrophy, and mild to severe myocardial inflammation, degeneration, and fibrosis. Aneurysm of the left ventricle and pericarditis also were common. Hearts from the starch, copper-deficient groups were much less hypertrophic, and very few were affected by myocardial inflammation, degeneration, or fibrosis. Defects of elastin or other structures were not observed in the aortas or pulmonary or coronary arteries of any specimens.

Development of copper deficiency in rats fed fructose or starch: Weekly measurements of copper indices in blood

Abstract Copper deficiency was induced in weanling rats fed diets whose sole source of carbohydrates was starch or fructose for 7 weeks. Conventional parameters of copper status, plasma copper concentrations, ceruloplasmin activity, and erythrocyte superoxide dismutase (SOD) activity-were longitudinally monitored weekly to follow the development of the deficiency and to correlate these indices with the degree of severity of the deficiency. Although 30% of the rats fed a copper-deficient fructose diet died and no deaths occurred in rats fed the copper-deficient starch diet, plasma copper, ceruloplasmin, and SOD activities were reduced to a similar extent in all rats fed copper-deficient diets regardless of the type of dietary carbohydrate. Thus, none of the indices used accurately reflected the greater degree of deficiency or mortality in rats fed the fructose diet deficient in copper. The results of the present study underscore the need for more sensitive tests or alternative parameters to assess copper status in living animals.

Modification of the United States' diet to effect changes in blood lipids and lipoprotein distribution

Twenty men, 19 premenopausal and 14 postmenopausal women consumed a diet for 13 weeks that supplied 35% of the calories from fat, 50% from carbohydrate, and 15% from protein. The diet was low in cholesterol, saturated fat, and salt, and high in complex carbohydrate and fiber. The 7-day menu was composed of common well-accepted foods prepared in a simple attractive manner. Plasma total cholesterol, LDL cholesterol, and VLDL cholesterol were reduced, but triglyceride levels were not different than after self-selected diets. When 20% of the complex carbohydrate was replaced by simple carbohydrate and other diet components remained optimal, triglyceride and VLDL cholesterol levels increased in men and premenopausal women and total cholesterol increased in premenopausal women. These results suggest that beneficial effects on the blood lipids and lipoprotein distribution of men and women may be obtained by minimal modification of a typical U.S. diet.

Lipoprotein status in sprague-dawley and LA/N-corpulent rats as affected by dietary carbohydrates

1. To compare the impact of type of carbohydrate, genotype and phenotype on the synthesis and levels of plasma lipoprotein protein. Sprague-Dawley rats and carbohydrate-sensitive LA/N-corpulent (cp) rats were fasted (2 days) and then fed diets containing 54% carbohydrate as either sucrose, fructose or cooked cornstarch for 2 days. 2. The amount of 3H-protein present in the VLDL + chylomicron fraction of Sprague-Dawley rats 2 hr after injection of 3H-leucine was affected by type of dietary carbohydrate: sucrose greater than fructose greater than starch. 3. Obese and lean LA/N-cp rats fed diets containing sucrose or fructose had lower concentrations of HDL protein and higher levels of 3H-protein in VLDL + chylomicron fraction than those fed starch. 4. Obese LA/N-cp rats had more HDL protein and higher levels of 3H-protein in VLDL + chylomicron fraction than their lean littermates.

Effects of Dietary Carbohydrate on Fasting Levels of Human Growth Hormone and Cortisol

Abstract Ten men and nine women aged 35–55 years consumed two diets for 6 weeks each in a crossover design. Diets provided identical foods with 30% of the kilocalories (kcal) as either sucrose or cooked wheat starch. Of the total kcal 43% was supplied as carbohydrate, 42% as fat, and 15% as protein. The dietary pattern consisted of two meals divided so as to provide 10% of the kcal at breakfast (0700–0830 hr) and 90% of the kcal at dinner (1630–1830 hr). Initial body weights were essentially maintained. Fasting human growth hormone (HGH) level decreased significantly as a function of time on diets. Fasting cortisol level differed significantly between Periods I and II regardless of whether or not diets contained starch or sucrose and was also affected by time on the study. The consumption of diets containing 30% of the kcal as either starch or sucrose in a gorging pattern apparently promoted changes in levels of HGH and cortisol in the direction that would favor lipid formation.

Enhancement of Intestinal Sugar Transport by Rats Fed Sucrose as Compared to Starch

The weight and length of the small intestine and the intestinal transport of sugars and amino acids were determined in Wistar rats fed diets containing either 54% starch or sucrose ad libitum

Effects of Sugars on Leucine and Lysine Uptake by Intestinal Cells from Rats Fed Sucrose and Stock Diets

Summary The effect of various dietary sugars on the uptake of 1 mM leucine and 1 mM lysine by intestinal cells isolated from stock-fed and sucrose-fed rats was determined. Leucine uptake was activated by 10 mM fructose and inhibited by 10 mM glucose or 20 mM sucrose on both diets. The major dietary effect noted was a significant increase in the inhibition of leucine by glucose in the sucrose-fed rats. The uptake of lysine was minimally affected by the sugars irrespective of the diet fed. These results demonstrate an important dichotomy in the properties of glucose and fructose transport in the intestine and suggest that dietary fructose may increase the transport of certain amino acids. We wish to thank John Putney for his very valuable technical assistance.