Type Of Dietary Carbohydrate Research Articles

Impairment of Glucose Tolerance in Copper-Deficient Rats: Dependency on the Type of Dietary Carbohydrate

Copper deficiency was induced in weanling rats in order to study the possible interaction between the types of dietary carbohydrate and copper deficiency on glucose tolerance. Weanling male rats were fed copper-deficient or copper-supplemented diets containing either 62% starch, fructose or glucose. During week 5 the fructose portion of the copper-deficient diet was replaced (20 rats) by starch (10 rats) or glucose (10 rats). During the 9th week, an oral glucose tolerance test was performed. Copper deficiency was associated with impaired glucose tolerance characterized by increased blood glucose and decreased insulin levels only in copper-deficient rats fed the monosaccharides fructose or glucose but not the polysaccharide starch. Changing the dietary carbohydrates in the copper-deficient diet from fructose to starch increased insulin levels and decreased blood glucose in response to the glycemic stress when compared to rats continuously fed fructose. Although both glucose and fructose feeding impaired the glucose tolerance, fructose was more diabetogenic. This could be demonstrated by some improvements in glucose tolerance when the copper-deficient rats were switched from the fructose to the glucose diet. The data indicate that copper deficiency per se dose not impair glucose tolerance.

Effect of dietary carbohydrates and copper status on blood pressure of rats

Copper deficiency was induced in rats by feeding diets containing either 62% starch, fructose or glucose deficient in copper for 6 weeks. All copper deficient rats, regardless of the dietary carbohydrate, exhibited decreased ceruloplasmin activity and decreased serum copper concentrations. Rats fed the fructose diet exhibited a more severe copper deficiency as compared to rats fed either starch or glucose. The increased severity of the deficiency was characterized by reduced body weight, serum copper concentration and hematocrit. In all rats fed the copper adequate diets, blood pressure was unaffected by the type of dietary carbohydrate. Significantly reduced systolic blood pressure was evident only in rats fed the fructose diet deficient in copper. When comparing the three carbohydrate diets, the physiological and biochemical lesions induced by copper deprivation could be magnified by feeding fructose.

The interaction of type of dietary carbohydrates with copper deficiency

The present study was designed to determine if the more severe copper deficiency in rats fed sucrose and fructose, as compared to starch, is due to a specific effect of the fructose or to a nonspecific effect of any simple carbohydrate. Seventy weanling male rats were fed, for 9 wk, copper-deficient diets or copper-supplemented diets containing either 62% starch, fructose, or glucose. Decreased hematocrit, serum copper, and ceruloplasmin concentrations but increased heart and liver weights, total liver lipid, and hepatic iron concentration were found in all copper-deficient rats regardless of the dietary carbohydrate. Feeding rats the high glucose diet decreased plasma albumin and liver glycogen but increased blood urea nitrogen when compared to rats fed starch. However, rats fed fructose generally exhibited a more severe copper deficiency as compared to rats fed either starch or glucose. The severity was characterized by lower (p < 0.05) body weight, liver glycogen, hematocrit, serum copper, and albumin. Conversely, liver and heart weights, blood urea nitrogen, and plasma glutamic oxaloacetic transaminase were higher (p < 0.05). Plasma cholesterol was increased by copper deficiency only in rats fed fructose or glucose. During the study, 17 of the 40 rats fed copper-deficient diets died; 66% of those fed fructose, 26% fed glucose, and 30% fed starch. These results suggest that the fructose moiety of sucrose is responsible for the increased severity of copper deficiency in rats fed sucrose as compared to starch.

Effect of dietary protein level and kind of carbohydrate on growth and selected pathological and biochemical parameters in female BHE rats

Female BHE 1 rats were fed one of four levels of dietary protein (6%, 8%, 20%, or 45% casein) with either sucrose or cornstarch from weaning to 175 days of age. At 100 days of age the females were mated with males fed the same respective diets. Unlike males of this strain, females fed 20% casein were comparatively resistant to the effects of the type of dietary carbohydrate. However, persistent stress of consuming either inadequate or excessive amounts of protein affected the influence of dietary carbohydrate source on growth, liver and kidney histopathology, and certain constituents of serum (total protein and cholesterol, lipoprotein fractions, BUN) and urine (albumin and transferrin excretion). In addition to the independent effects of protein level or carbohydrate source, many parameters were influenced by the interaction of these nutrients. Fatty liver infiltration was most severe when sucrose was fed with 6% protein. Females fed 45% protein with sucrose were beginning to develop signs of kidney nephrosis by 175 days of age.

Effect of Chronic Hyperinsulinism on Metabolic Parameters and Histopathology in Rats Fed Sucrose or Starch

The purpose of this study was to determine the effects of chronic hyperinsulinism on metabolic risk factors and on the histopathologic changes in the heart and aorta of rats fed sucrose or starch diets for 8 months. Hyperinsulinism was attained by the subcutaneous implantation of osmotically driven minipumps partially coated with paraffin so as to deliver 3 units/day of porcine insulin for up to 4 weeks. Control rats were implanted with pumps containing 1.6% glycerol. There were initially 12 rats each in four groups of rats; sucrose-insulin, sucrose-control, starch-insulin, starch-control. Nonfasted blood insulin levels obtained every 3 weeks from the tail vein averaged 553, 156, 426, and 107 µU/ml in sucrose-insulin, sucrose-control, starch-insulin, and starch-control rats, respectively. Sucrose-fed rats had greater body weight, deposited more body fat, and had higher levels of nonfasting insulin and glucose and 6-hour fasted triglyceride than did starch-fed rats. Rats receiving insulin had greater body weight and removable fat weight, higher levels of nonfasting and fasting insulin and lower level of nonfasting glucose than did rats not receiving insulin. Neither hyperinsulinism nor the type of dietary carbohydrate significantly affected the amount of blood cholesterol. Histopathology of the heart and aorta revealed no unique changes above those commonly observed in laboratory rats as a function of age.

Triacylglycerol Secretion in Rats: Effects of Essential Fatty Acids and Influence of Dietary Sucrose, Glucose or Fructose

The rate of triacylglycerol (TG) secretion into plasma was determined in vivo in essential-fatty-acid(EFA)-adequate and EFA-deficient rats fed for 8–10 weeks on diets containing either sucrose, glucose or fructose (66.5% wt/wt) as the sole source of carbohydrate. The rate of TG secretion was increased in EFA-deficient rats, irrespective of the type of dietary carbohydrate. The secretion rate in EFA-deficient rats fed fructose was 50% higher than the rate in similar animals fed glucose or sucrose, although in the EFA-adequate rats, the secretion rate with fructose was not significantly higher than with sucrose or glucose. The concentrations of triacylglycerols and cholesteryl esters in plasma were generally reduced in EFA deficiency, whereas the concentrations of these lipids in liver were increased. Plasma free fatty acid concentrations were unchanged. The fatty acid composition of plasma and hepatic lipids was altered both by EFA deficiency and to a smaller extent by the type of dietary carbohydrate. The concentration of plasma glucagon was reduced in the deficient animals, although plasma insulin concentration was not affected. The resulting increase in the plasma insulin:glucagon molar ratio may explain some of the alterations in lipid concentrations and in lipid metabolism observed in EFA deficiency.triacylglycerol secretion EFA deficiency dietary carbohydrate insulin glucagon lipid compositions

Effects of dietary cholesterol level and type of dietary carbohydrate on hepatic and plasma sterols in the gerbil.

The influence of dietary cholesterol and type of carbohydrate on the level of free cholesterol, esterified cholesterol, and the type of cholesteryl esters in the liver of the Mongolian gerbil, Meriones unguiculatus, was studied by a series of experiments. Semipurified diets were fed in which the level of cholesterol was comparable to human intakes (0.1% by weight) or higher (0.5%) and the carbohydrate source was starch or sucrose or a mixture there of. All diets were devoid of bile acid and contained relative amounts of carbohydrate, protein, fat, and type of fat which approached human intakes in North America. Free cholesterol levels in liver were 60-140% greater and 15-30% greater when diets were supplemented to contain sterol levels of 0.5 and 0.1%, respectively, whereas hepatic cholesteryl ester levels were 11- to 23- fold greater and 2- to 3-fold greater, respectively. Levels of cholesterol (both free and esterified) in plasma were 175-725% greater in animals consuming 0.5% dietary cholesterol and 30-105% greater in gerbils ingesting 0.1% cholesterol as compared with levels in gerbils fed a basal (unsupplemented) diet. The type of dietary carbohydrate had a moderate influence on cholesterol levels in liver and plasma when dietary cholesterol was supplied at 0.5%. The percent contribution of 18:1 fatty acid to the liver cholesteryl esters was greater in cholesterol-supplemented gerbils, while the proportions of 16:0 and 18:2 acids were lower. These results indicate that the gerbil is highly sensitive to low levels of dietary cholesterol in diets which are also free of bile acid, in contrast to many other species, including the laboratory rat. The present findings support the usefulness of the gerbil model for studying the influence of dietary sterol on cholesterol metabolism.

Effects of Dietary Cholesterol and Type of Dietary Carbohydrate on Hepatic and Plasma Glycerides and Phospholipids in the Gerbil

The influence of dietary cholesterol at levels of 0.01–0.5% (by weight) and carbohydrate type (starch, sucrose or a starch-sucrose mixture) on levels and composition of hepatic and plasma glycerides in the male Mongolian gerbil (Meriones unguiculatus) was studied. Hepatic and plasma triglyceride (TG) levels were generally higher with dietary cholesterol supplementation (0.1 and 0.5%), and animals fed sucrose diets exhibited very low levels of hepatic and plasma TG. The mixed carbohydrate (starch-sucrose) did not affect glycerides in a way that could be interpolated from feeding starch or sucrose diets alone. The percent of 16:0 in liver TG was depressed with cholesterol-feeding (at the 0.5% level only), whereas the percent of 18:1 was elevated. Sucrose diets produced higher percentages of 18:0 in liver TG. Dietary cholesterol elevated concentrations of plasma but not liver phospholipid (PL). Percentages of 20:4ω6 and 22:6ω3 acids in liver and plasma PL were significantly depressed by cholesterol supplementation, whereas the percent of 18:2 in liver PL was higher when feeding cholesterol and starch (not sucrose). Dietary cholesterol produced higher levels of hepatic 1,2-diglyceride with lower percentages of 18:0 and 20:4ω6 and higher percentages of 18:1 and 18:2. Dietary cholesterol may possibly influence fatty acid elongation and desaturation reactions as well as transacylation reactions in phospholipid synthesis. In this regard, compositional data suggested a suppressing effect of dietary cholesterol on 22:6ω3 formation as exemplified by a 40% diminution in the docosahexaenate content of hepatic phosphatidylethanolamine in gerbils fed a 0.5% cholesterol diet for only 7 days.cholesterol carbohydrate type gerbil triglyceride 1,2-diglyceride phospholipid phosphatidylcholine phosphatidylethanolamine

Interaction of the level of dietary fat and type of carbohydrate in the regulation of hepatic lipogenesis in the mouse.

We have studied hepatic and extrahepatic lipogenesis in mice fed diets containing 0, 5, 10, or 15% corn oil in which the carbohydrate was one of fructose, sucrose, glucose, or wheat starch. Meal-fed animals were trained to eat a quantity of food such that at a given level of fat ail animals consumed the same amount of carbohydrate. Fatty acids synthesis in vivo, acetyl CoA carboxylase, fatty acid synthetase, ATP citrate lyase, glucose-6-phosphate dehydrogenase, and malic enzyme were determined. At 0 and 5% corn oil the values generally decreased in the order fructose &gt; sucrose &gt; glucose &gt; wheat starch. At 10 and 15% corn oil differences due to the type of carbohydrate were less pronounced. The effect of dietary carbohydrate on glucokinase activity followed the reverse pattern with the values decreasing in the order wheat starch &gt; glucose &gt; sucrose &gt; fructose. The results obtained demonstrate that hepatic lipogenesis was increased in mice consuming fructose or sucrose independent of carbohydrate intake or the level of dietary fat. However, total capacity for lipogenesis was greater in glucose-fed mice than those consuming wheat starch, fructose, or sucrose. Regardless of the carbohydrate in the diet, as dietary fat increased all the lipogenic parameters measured declined.Increasing corn oil from 0 to 15% caused a greater change in lipogenic capacity than the change due to the various carbohydrates. The percentage of total synthesis which occurred in liver was greater in mice fed fructose or sucrose. This increased contribution by the liver was unaltered by dietary fat which may contribute to the hypertriglyceridemia in such animals. Compared with diets based on glucose or wheat starch, diets based on fructose or sucrose do not cause increased lipogenesis in meal-fed mice if the diets contain more than 30 calorie percent fat. Our results suggest that when diets contain fat a a level similar to that in North American diets, the effects of the type of dietary carbohydrate on lipogenesis are minimal.

Dietary Components and Gastrointestinal Growth in Rats

Groups of young rats, weighing 50--80 g, were fed nutritionally adequate purified diets containing different types of protein, carbohydrate, lipid and fiber, or no fiber. Effect of diet on growth of the gastrointestinal tract was evaluated from differences in size of the organs and organ weight: body weight ratios at the end of a 5 week feeding period. The results suggested that type of dietary protein (casein or soy protein), or carbohydrate (dextrose, sucrose, hydrolyzed starch), or lipid (mixed animal + vegetable, corn oil or lard) did not seem to influence growth of the stomach, small intestine, cecum or colon. However, fiber (mixed vegetable, from oats or cellulose) in the diet appeared to have enhanced growth of the small intestine, and more markedly that of the colon (both its length and weight) but not that of the stomach or cecum. On the basis of crude fiber, growth enhancement appeared to be greater in response to the diet with mixed animal and vegetable components than to the semi-purified diets containing oats or cellulose.

Effect of the Type and Proportion of Dietary Carbohydrate on Serum Glucose Levels and Liver and Muscle Glycogen Synthesis in the Rat

The effect of the type of dietary carbohydrate on oral glucose tolerance and on in vivo incorporation of labeled glucose or fructose into liver and muscle glycogen in the rat were investigated. The intake of fructose or sucrose reduced, as compared with starch or glucose, glucose incorporation into liver glycogen and caused a slight deterioration of the glucose tolerance. These effects were observed already when 50% of the total dietary carbohydrate was substituted by fructose or sucrose. The incorporation of labeled glucose into muscle glycogen was not affected by the type of dietary carbohydrate. Specific radioactivity of liver and muscle glycogen and the concentration of muscle glycogen after administration of labeled fructose were higher in fructose-adapted than in glucose-adapted rats.

Serum and liver lipid responses to 3-hydroxy-3-methylglutaric acid in rats on different carbohydrate diets.

Groups of male adult albino rats were administered 3-hydroxy-3-methylglutaric acid (HMG) intraperitoneally along with six diets differing only in the type of carbohydrate used. Groups not treated with HMG served as controls. HMG showed a significant cholesterol- and tri-glyceride-lowering effect in the whole serum, serum beta-lipoproteins, and liver of animals on all types of dietary carbohydrates. The effect was more marked in glucose, fructose, sucrose, and lactose. The phospholipid levels in whole serum, serum beta-lipoproteins, as well as in liver were also significantly lowered on all types of carbohydrates except dextrin and starch fed animals, where it had no effect on liver levels. The lipid-lowering effect of HMG seems to be independent of the type of carbohydrate in diet.

Nitrogen source primarily supplied by amino acids and the efficacy for maximal growth of rats.

The effect of osmotic pressure of diets on be food intake of young rats was investigated by comparing the nutritional effect of casein with the corresponding amino acid mixture at 3.2% nitrogen level. Changes in the osmolarity of diets due to the type of dietary carbohydrate had a little effect on food intake, whereas partial substitution of casein for amino acids resulted in significant increase in food intake. Weight gain and food intake of rats fed the 25% replaced amino acid diet were compared with those of rats fed the casein diet. Food intake was lower at 12.5% replacement than at 25% replacement. These observation suggest that a well-balanced amino acid mixture supported maximal growth of rats when 25% of the amino acid mixture was replace with casein. This suggestion could be experimentally confirmed by using an amino acid mixture based on the amino acid composition of whole-egg protein.

Conversion of Type III Hyperlipoproteinaemia to Type IV Hyperlipoproteinemia by a Fat‐Free, Carbohydrate Rich Diet

Abstract. Hyperlipoproteinaemia type III has been considered a clear cut clinical entity characterized by the presence of cholesterol rich “floating” beta very low density lipoproteins (VLDL) after ultracentrifugation. Carbohydrate inducibility is pronounced in type III. This study was undertaken to elucidate the effect of a high carbohydrate diet in type III as an effort to clarify a suggested association between type III and IV hyperlipoproteinaemia. On an isocaloric fat free carbohydrate rich diet the lipoprotein pattern changed as the VLDL triglycerides increased 31 per cent on average and LDL and HDL cholesterol decreased by 40 and 22 per cent. The high ratio cholesterol/triglycerides in VLDL was normalized. The lipoprotein levels in serum after carbohydrate induction showed all characteristics of a type IV with high VLDL triglycerides, normal cholesterol/triglyceride ratio in VLDL, subnormal cholesterol levels in LDL and HDL with changed relation between LDL1 and LDL2. On electrophoresis the floating beta band disappeared. It is probable that depending on the nutritional situation, the metabolic defect in type III may be expressed either as a type III or a type IV. An explanation of the effects of the carbohydrate rich diet on the lipoprotein pattern is suggested.

Conversion of Type III Hyperlipoproteinaemia to Type IV Hyperlipoproteinaemia by a Fat‐Free, Carbohydrate Rich Diet

Hyperlipoproteinaemia type III has been considered a clear cut clinical entity characterized by the presence of cholesterol rich "floating" beta very low density lipoproteins (VLDL) after ultracentrifugation. Carbohydrate inducibility is pronounced in type III. This study was undertaken to elucidate the effect of a high carbohydrate diet in type III as an effort to clarify a suggested association between type III and IV hyperlipoproteinaemia. On an isocaloric fat free carbohydrate rich diet the lipoprotein pattern changed as the VLDL triglycerides increased 31 per cent on average and LDL and HDL cholesterol decreased by 40 and 22 per cent. The high ratio cholesterol/triglycerides in VLDL was normalized. The lipoprotein levels in serum after carbohydrate induction showed all characteristics of a type IV with high VLDL triglycerides, normal cholesterol/triglyceride ratio in VLDL, subnormal cholesterol levels in LDL and HDL with changed relation between LDL1 and LDL2. On electrophoresis the floating beta band disappeared. It is probable that depending on the nutritional situation, the metabolic defect in type III may be expressed either as a type III or a type IV. An explanation of the effects of the carbohydrate rich diet on the lipoprotein pattern is suggested.

Gastric emptying time and absorption of simple and complex carbohydrates in Macaca mulatta.

AbstractRecent studies of nonhuman primates have shown that the amount and type of dietary carbohydrate influences the development of atherosclerotic lesions. In an effort to examine the gastrointestinal handling of simple and complex carbohydrates, measurements of gastric emptying times and uptake of C14 labeled carbohydrates were made for six female Macaca mulatta.A significantly smaller volume of sucrose solutions remained in the stomach after 60 minutes than solutions containing an equal amount by weight of dextrin. Similarly, when solutions of equal osmotic pressures but unequal weights of sucrose and dextrin were used, a significantly smaller volume of the sucrose solution remained in the stomach after 60 minutes. These findings are consistent with the idea that breakdown of dextrin by pancreatic amylase results in an increase in osmotic pressure of the intestinal contents and a slowing of gastric emptying. No significant differences in the levels of glucose or total C14 labeled carbohydrates were found in the peripheral blood following ingestion of C14 labeled sucrose or dextrin. This finding suggests that although an initial difference in the rate of gastric emptying of these carbohydrates exists, other factors, such as the rate of production and activity of pancreatic amylase, activity of intestinal disaccharidases, and intestinal mucosal transport, tend to equalize the rate of absorption of these sugars.

Blood constituents and hepatic lipids in rats fed sucrose or starch with or without cyclamate

To study the effect of type of dietary carbohydrate and cyclamate on selected tissue components, rats were fed basal diets that contained sucrose or cornstarch: dextrin (2:1) with 0, 2, or 10% calcium cyclamate. Substitution of starch:dextrin for sucrose in the basal diet did not significantly affect the concentrations of blood hemoglobin, serum protein, cholesterol or total lipids in liver, or weight gain of the animals. Substitution of 2% cyclamate for sucrose did not appear to affect significantly the parameters studied, except that liver weight and total amino acid concentration decreased. Animals fed starch:dextrin with 2% cyclamate had lower weight gains than those of their respective controls, whereas liver cholesterol and total lipid concentrations were increased. Dietary cyclamate decreased the liver weight of all experimental groups. Weight gains of animals fed sucrose or starch:dextrin with 10% cyclamate in replacement of carbohydrate were, respectively, 41 and 58% lower than those of their respective controls. Substitution of 10% cyclamate for sucrose or starch:dextrin decreased blood hemoglobin. The total concentration of essential amino acids in sera of rats fed 10% cyclamate with sucrose or starch:dextrin approached or exceeded that of the respective controls. The data indicate that the effect of cyclamates on the level of certain tissue components may be related to the type of carbohydrate fed with cyclamate.

Serosal accumulation of amino acids and hepatic lipid levels of rats fed several carbohydrates

The influence of the type of dietary carbohydrate on the in vitro serosal accumulation of amino acids in rat intestinal tissue was examined. In addition, the hepatic concentration of several classes of lipids was determined. 1. 1. Food consumption and body weight gains of rats fed raw potato starch were significantly higher than those fed cooked potato starch, cornstarch, sucrose, glucose, or dextrin. Rats fed sucrose exhibited significantly lower body weight gains than those on other treatments. 2. 2. The in vitro serosal accumulation of amino acids was lowest in rats fed raw potato starch and sucrose. These animals also exhibited the greatest and least weight of intestinal tissue per unit of length, respectively. There was little difference between other dietary treatments in terms of serosal accumulation rate, although the tissue of dextrin-fed rats tended to show a higher rate of passage. 3. 3. Significantly higher levels of total lipid, free cholesterol, and neutral fat were found in the hepatic tissue of rats fed sucrose. There were no treatment differences in the levels of total cholesterol, phospholipids, free fatty acids, or the activity of glucose-6-phosphate dehydrogenase or malate dehydrogenase.

Ultracentrifugal analysis of lipoproteins during adaptation to high carbohydrate diet in type II hyperlipoproteinemia and normals.

SummaryChanges in ultracentrifugal lipoprotein patterns on the second and fifth day of high carbohydrate feeding in normals and patients with Type II hyperlipoproteinemia are reported. A significant increase in Sof 100–400 class lipoproteins and decrease in Sof 0–12 class lipoproteins occurred. Sof 20–100 class lipoproteins showed a significant increase in all subjects except one mother–daughter pair with Type II hyperlipoproteinemia. Less consistent patterns of change were seen in F1.20 (0–3.5) and F1.20 (3.5–9) class lipoproteins. Sof 12–20 class lipoproteins showed no consistent change.

Long-term effects of dietary sucrose and starch on serum lipids and atherosclerosis in miniature swine

Miniature swine were fed cholesterol-containing diets in which approximately 60% of calories were derived from either sucrose or cornstarch. The effects on serum concentration of lipids, glucose, and insulin and on the development of atherosclerosis were studied. There were no significant differences in serum cholesterol or triglyceride concentration between swine consuming either diet for up to 2 years. There was, however, significantly more variability in the serum cholesterol levels of animals consuming sucrose compared with starch. This was due primarily to two animals in the sucrose group that maintained substantial hypercholesterolemia over the length of the experiment. No significant differences were seen between dietary groups in glucose or insulin concentrations either in fasting levels or in response to intravenous tolbutamide. The extent of aortic atherosclerosis in animals of the two dietary groups was not significantly different after 1 and 2 years on experiment. After 1 year, however, the coronary arteries from the sucrose-fed animals were significantly more diseased than those from the starch-fed animals. This difference was not present after 2 years. Consequently, in the absence of an effect of the type of dietary carbohydrate on the serum cholesterol concentration, the substitution of sucrose for starch did not result in a significantly greater amount of atherosclerosis. Rather, the extent of atherosclerosis appeared more dependent on the serum cholesterol concentration which showed considerable individuality of response, particularly among animals consuming the diet containing sucrose. The two animals from the sucrose group that maintained the highest serum cholesterol concentration also had the greatest extent of atherosclerosis.