Biomedical subjects

N G Asp

Publications and source records attributed to N G Asp.

At least 55 records · Page 3Linked to original sources

PubMed1987

Enzyme resistant starch fractions and dietary fibre.

Starch fractions that are more or less enzyme resistant may behave like dietary fibre, both physiologically and analytically. Ungelatinized granules from potatoes, high amylose maize and green bananas are poorly digested. Starch made resistant to amylase due to new covalent bindings, formed at heat treatment or present in starch derivatives used as food additives, may also be more or less undigestible. "Resistant starch" present in bread and corn flakes is probably retrograded amylose. It is undigestible in the small intestine, but readily degraded by the large bowel microflora. Amylose-lipid complexes seem to be completely absorbed in spite of their resistance to amylase degradation in vitro. Since undigestible starch fractions behave physiologically like non-starch polysaccharides, they should be included in the dietary fibre concept. "Resistant starch" is analysed as glucose based fibre with all current methods except one, which includes an initial DMSO solubilization step.

Amylases↗

PubMed1987

Effects of leguminous seeds in a mixed diet in non-insulin-dependent diabetic patients.

The effects of moderate addition of leguminous seeds to a mixed diabetic diet were evaluated in 15 inadequately controlled patients with non-insulin-dependent diabetes mellitus. A control diet and a diet with an increased content of peas and beans (leguminous diet) were given consecutively for a 3-week period each on a metabolic ward. Seven of the patients started with the control diet and 8 with the leguminous diet. On an energy basis the diets comprised 20% protein and 33-34% fat, the ratio between polyunsaturated and saturated fatty acids was 1.4. The analysed dietary fibre contents of the control and leguminous diets were 24 and 37 g/day per 6.7 MJ (1,600 kcal) respectively. The content of digestible carbohydrates was similar in the 2 diets. The mean body weight did not differ after the 2 dietary treatment periods. All patients showed improved glucose control during treatment irrespective of the type of diet given. The fasting blood glucose concentration on admission was 14.3 +/- 0.9 mmol/l (mean +/- SEM). This value had decreased to 9.9 +/- 0.8 during the last week of the control period and to 9.7 +/- 0.6 during the last week of the leguminous diet period. The mean postprandial glucose concentration at 3 pm was significantly lower during the leguminous diet period. The mean urine glucose excretion was significantly lower during the leguminous diet period. The fasting serum lipid concentrations decreased during treatment with each diet, but there were no significant differences between these values at the end of the 2 diet treatment periods.(ABSTRACT TRUNCATED AT 250 WORDS)

Diabetes Mellitus, Type 2↗

PubMed1986

Fermentation of dietary fibre in the intestinal tract: comparison between man and rat.

1. The breakdown and faecal bulking capacity of dietary fibre preparations from wheat bran, apple, cabbage, carrot, and guar gum were compared in man and rat. 2. The degradation of the fibre showed good correlation between man and rat (r 0.99, regression coefficient 0.86). Wheat bran was the least well-digested, 66 and 59% of the neutral sugars being excreted in faeces of man and rat respectively. The breakdown of the fibre in apple, cabbage, carrot and guar gum was more complete and 4-29% of the neutral sugars were recovered in faeces. 3. The main dietary fibre constituents in each preparation were degraded to a similar extent in man and rat. The main dietary fibre constituents of apple, carrot, cabbage and guar gum were almost completely degraded. Of the xylose in wheat bran 45% (man) and 48% (rat) were recovered in faeces. However, the percentage excretion of glucose and arabinose from bran was higher in man. 4. A faecal glucan other than cellulose was identified in human faeces after guar gum, and has been provisionally identified as starch. No such glucan occurred in rat faeces. 5. A good correlation between the faecal bulking capacity in man and rat was seen (r 0.97, regression coefficient 0.56). Wheat bran had the best bulking capacity, while that of apple, cabbage, carrot and guar gum was less pronounced. Faecal bulking was inversely related to the amount of fibre which was water-soluble in each preparation. 6. It is concluded that this rat experimental model is useful for the prediction of fermentative breakdown and bulking capacity of dietary fibre in man. However, more comparative studies are needed to evaluate animal experiments regarding other physiological effects of dietary fibre.

Adult↗

PubMed1986

Reduced glycemic response to beet-fibre meal in non-insulin-dependent diabetics and its relation to plasma levels of pancreatic and gastrointestinal hormones.

Standardized breakfasts with or without beet-fibre were given, in random order, to non-insulin-dependent diabetics. The blood glucose levels were monitored continuously and hormonal responses were determined at regular intervals for 3 hr. After the beet-fibre breakfast including 10.8 g dietary fibre from the sugar beet, the glucose plateau level and the area below the curve were lower than after the control meal. The rate of glucose decrease was also slower after the beet-fibre meal. There were no notable differences with regard to the plasma levels of insulin, C-peptide or glucagon. The gastric inhibitory polypeptide response was greater during the first part of the curve, while the somatostatin response after the beet-fibre meal displayed a significantly larger total area below the curve. The results suggest that the diminished glycemic response after the beet-fibre meal is associated with an increased response of somatostatin, giving a reduced glucose absorption and a delayed gastrointestinal transit time.

Aged↗

PubMed1985

Dietary fibre fermentation in the rat intestinal tract: effect of adaptation period, protein and fibre levels, and particle size.

1. The fermentative breakdown of one resistant type of dietary fibre (wheat bran) and one easily-fermented fibre (low-methoxyl pectin) was studied with respect to the length of the adaptation period and fibre level in the diet. The breakdown of the resistant fibre was also studied regarding the protein level in the diet and particle size of the fibre. 2. Prolongation of the adaptation period from 4 to 18 d decreased the faecal dry weight considerably. The excretion of dietary fibre however, was similar, whereas a decrease in faecal nitrogen excretion could be seen. 3. A level of dietary protein of less than 50 g/kg impaired the fermentation of wheat-bran fibre, whereas a level higher than 100 g protein/kg did not further increase the degree of fermentation of the fibre. 4. The particle size did not change the fermentability of the fibre, equal amounts of the main components of coarse and milled bran being excreted in faeces. 5. Two different levels of wheat-bran fibre (48 and 96 g/kg) in the diet did not influence the fibre breakdown. Similar results were obtained with two levels of fibre from low-methoxyl pectin (42 and 84 g/kg), but a tendency towards a decreased percentage of faecal excretion of uronic acids was seen at the lower level of low-methoxyl pectin.

Adaptation, Physiological↗

PubMed1985

Bulk laxatives: their dietary fibre composition, degradation, and faecal bulking capacity in the rat.

The intestinal dietary fibre degradation and faecal bulking capacity of various bulk laxatives were investigated by means of balance experiments on rats. Nitrogen, fat, and mineral excretion in faeces was also studied. The dietary fibre content of the various bulk laxatives was quite different (in g/kg dry matter): ACO fibre tablets (barley and citrus pulp), 451; Fiberform (wheat bran-based), 817; Inolaxol (sterkulia gum), 696; and Vi-Siblin (ispaghula husk), 533. The increase in faecal dry matter per 1 g dietary fibre was similar with ACO fibre tablets, Fiberform, and Vi-Siblin. Inolaxol gave a significantly (p less than 0.001) higher faecal dry-weight increment, mainly due to an increased mineral excretion. Of the dry-weight increment, 59-82% constituted undegraded dietary fibre. Thus, 68-97% of the fibre passed through the gastrointestinal tract without being degraded. All the bulk laxatives caused a similar increase in the faecal N content, whereas the increase in faecal lipids was most pronounced with Vi-Siblin. The water-holding capacity of faeces was more pronounced with Inolaxol and Vi-Siblin than with ACO fibre tablets and Fiberform.

Animals↗

PubMed1985

Hormonal and metabolic responses to breakfast meals in niddm: comparison of white and whole-grain wheat bread and corresponding extruded products.

The post-prandial glucose and hormonal responses were followed in nine non-insulin-dependent diabetics after four randomized breakfast meals containing mainly wheat products. The effect of conventionally baked breads was compared with extruded crispbread-like products prepared from white or whole-grain wheat flour, respectively. The extruded whole-grain product gave significantly larger areas under the glucose and insulin curves than the corresponding baked bread, and resulted in higher C-peptide, gastric inhibitory polypeptide, and glucagon concentrations at certain time points. The mean incremental areas under the glucose curves were similar after white bread and the two extruded crispbread-like products. There were no significant differences between white and whole-grain bread. The results indicate that baked whole-grain wheat bread is to be preferred to corresponding extruded products in non-insulin-dependent diabetes mellitus.

Adult↗

PubMed1984

Effects of an increased content of cereal fibre in the diet of Type 2 (non-insulin-dependent) diabetic patients.

The metabolic effects of an increased dietary content of cereal fibre were studied in 14 Type 2 diabetic subjects. They were given two isoenergetic diets in randomised order during two consecutive 3-week periods. A diabetic diet, containing 18.9 g dietary fibre/6.7 MJ (1600 kcal), was compared with a diet of identical composition except for an increased content of cereal fibre (42.4 g dietary fibre/6.7 MJ). The mean blood glucose level and the urinary glucose excretion were significantly lower in patients on the cereal-fibre-rich diet, while the serum insulin concentrations were similar. The mean blood glucose level was significantly reduced at 0700 h by 6% (p less than 0.05) and at 1100 h by 13% (p less than 0.01) on the high-fibre diet. Consequently the insulin/glucose ratio was higher (33%, p less than 0.02) in patients on the fibre-enriched diet. There were only minor differences with regard to the serum lipoprotein concentrations. The lipoprotein lipase activities were similar in the two dietary groups. The reduction of blood glucose concentrations together with unchanged serum insulin concentrations is compatible with improved peripheral insulin sensitivity.

Aged↗

PubMed1984

Dietary fibre in bread and corresponding flours--formation of resistant starch during baking.

Dietary fibre, assayed with an enzymatic/gravimetric method, was higher in wheat/rye bread than in the corresponding flours. The increase was most pronounced in crumbs from bread baked with mainly low-extraction-rate flour, and could be accounted for to a large extent as "resistant starch", i.e. a starch fraction available to amyloglucosidase only after solubilization with 2 m-KOH. The resistant starch was formed at dough-making and/or baking and did not increase further during freezing or storage at room temperature. The chemical modifications leading to resistant starch formation remain to be investigated. Starch-lipid complexes are probably not involved, since these are hydrolyzed by the heat-stable amylase used in the dietary fibre assay.

Bread↗

PubMed1984

Nutrient intake and health status of lactovegetarians: chemical analyses of diets using the duplicate portion sampling technique.

Six middle-aged lactovegetarians (three men and three women) collected copies of four 24-h diets using the duplicate portion sampling technique. By chemical analyses, the nutrient composition of the lactovegetarian diet was determined in detail and compared with that of a mixed Swedish diet (normal) and a vegan diet (vegan) studied previously. The nutrient composition of the lactovegetarian diet expressed per 1000 kcal represented an average between normal and vegan diets. It was in closer agreement with Swedish recommended dietary allowances than the normal Swedish diet. Thus, the lactovegetarian diet contained 35% of the energy as fat and was rich in polyunsaturated fatty acids, especially linoleic acid, which resulted in a polyunsaturated/saturated fat ratio of 0.6. The lactovegetarian diet had a cholesterol concentration only half of that of a normal diet. Protein content and amino acid composition were well above recommendations. The lactovegetarian diets contained less sucrose than normal and vegan diets, but the sum of the intake of low molecular weight carbohydrates was comparable to normal and vegan diets. Dietary fiber was three times higher than in a normal diet. Essential minerals and trace elements, ie, Ca, Mg, Na, K, Fe, Zn, Cu, Se, satisfied current requirements. The intake of vitamin B12 by the lactovegetarians was around 1.4 micrograms daily, which is below the recommendations. The intake of folates was high, 300 to 400 micrograms daily. The clinical and biochemical investigation of the subjects revealed no signs of nutritional deficiency. Their plasma lipoproteins and the blood pressures were low for their age, in agreement with observations made earlier in a group of vegans.

Animals↗

PubMed1984

Effect of dietary fibre on blood glucose, plasma immunoreactive insulin, C-peptide and GIP responses in non insulin dependent (type 2) diabetics and controls.

A high fibre and a low fibre breakfast meal were given to eight non insulin dependent diabetics ( NIDD ), and eight controls. Blood glucose response was monitored continuously for three hours and characterized using a straight line model. After the high fibre meal the rates of increase and decrease in blood glucose concentration were slower both in diabetics and controls than after the low fibre meal. The delay time, however, i.e. the time from meal intake to the start of glucose increase, hypothetically corresponding to gastric emptying time, was the same after both test meals. The postprandial glucose increment calculated as the area under the 0-120 min curve was lower after the high fibre meal in the NIDD , but not in the controls. The two-hour C-peptide and gastric inhibitory polypeptide values were lower for the diabetics after the high fibre breakfast. The results indicate a prolonged carbohydrate digestion and/or absorption after high fibre breakfast.

Adult↗

PubMed1983

Small intestinal dipeptidases and disaccharidases in uraemic rats on a low protein diet.

Small intestinal dipeptidases (substrate: glycyl-L-leucine, L-methionyl-L-methionine, and L-alanyl-L-proline) were determined in uraemic and sham-operated rats given normal protein diet (24%), low protein diet (6%), and total parenteral nutrition for 10-14 days. Disaccharidases (substrate: maltose, sucrose, trehalose, and lactose) were measured after normal and low protein diet orally. Glycyl-L-leucine and L-methionyl-L-methionine splitting activities were increased on normal protein diet but decreased after low protein feeding in uraemic rats. Parenteral nutrition further lowered the enzyme activity. L-Alanyl-L-proline dipeptidase activity showed an inverse relation to protein intake with the highest values after parenteral nutrition. Lactase increased in uraemic rats after low protein feeding and was the only disaccharidase to be affected by the nutritional change. It is suggested that the changes of the intestinal dipeptidase activities in uraemia are adaptive to variation in the luminal content of di- and oligopeptides because of the type of nutrition given.

Animals↗

PubMed1983

Effects of dietary fiber on pancreatic enzyme activities of ileostomy evacuates and on excretion of fat and nitrogen in the rat.

Ileostomized rats were fed diets with different fiber content. The addition of 5% pectin to the diet caused an increase in the wet weight, fat content, amylase activity per gram, and lipase output of the ileostomy evacuates. Twenty percent wheat bran in the diet increased weight, fat and nitrogen content, and trypsin output of the evacuates. In normal rats pectin added to a meal containing 3H-labeled triolein increased the isotope activity of the feces, indicating an impaired fat absorption. In rats operated on with occlusion of the pancreatic ducts with a tissue glue, the fat absorption was, however, not significantly affected by pectin. The results of the study show that fiber can cause a change in the intestinal enzymatic milieu of ileostomized rats and can cause steatorrhea, which can be explained, at least partly, by malabsorption.

Amylases↗

PubMed1982

Fermentation of dietary fibre components in the rat intestinal tract.

1. The fermentative breakdown of dietary fibre from various sources in the intestinal tract was studied using rat balance experiments and gas-liquid chromatograhic analysis of dietary fibre monomers in feed and faces. 2. On a basal diet with 690 g maize starch/kg but no added fibre, small but detectable amounts of polymeric glucose, rhamnose, arabinose, xylose, galactose, mannose and uronic acids, i.e. sugars occurring in dietary fibre, were excreted in faeces. 3. Dietary fibre in wheat bran was rather resistant to fermentation; 63% was recovered in the faeces. Guar gum, on the other hand, was almost completely fermented, whereas 19 and 25% of the uronic acids in low and high methoxylated pectin respectively, were excreted in faeces. The various constituents of sugar-beet dietary fibre (approximately equal amounts of arabinose-based hemicellulose, pectin and non-starch glucan (cellulose)) showed quite variable availability for micro-organisms in that 6-12% of the arabinose, 17-25% of the uronic acids, and 52-58% of the cellulose were recovered in the faeces. 4. Faecal nitrogen excretion increased on addition of any one of the dietary fibre preparations studied, resulting in decreased true and apparent protein digestibility values. 5. The faecal dry weight increment was most pronounced when feeding bran and could then almost be accounted for by the remaining fibre and by protein. The less-prominent bulking effect of guar gum and pectins, that were much more extensively fermented, could be only partly explained by dietary fibre and protein.

Animals↗

PubMed1982

Hepatic free choline and betaine and the utilization of dietary protein in the choline-deficient rat.

In the rat, exclusion of choline from a carbohydrate-rich, 10% casein diet, resulted in a drastic reduction of betaine in the liver. The amount of unesterified choline was not lowered to the same extent. Both unesterified choline and total lipids in the liver were increased by rats fed a choline-deficient diet supplemented with 0.5% L-methionine compared to rats given an unsupplemented choline-deficient diet. The amount of betaine was low in both groups compared to choline-supplemented rats. Dietary choline deficiency lowered the biological value of casein only slightly. Statistically significant effects were seen only in some of the experiments when potato starch was used as the carbohydrate source but not when maize starch was used. The choline-deficient potato starch diet gave rise to a more severe liver fattening that the corresponding maize starch diet.

Adipose Tissue↗

PubMed1982

Decreasing incidence of acute appendicitis, with special reference to the consumption of dietary fiber.

The incidence of acute appendicitis and the total number of appendectomies performed in the adult population admitted to our medical center are both decreasing. The cause is not clear. Better nutrition and the wide-spread use of antibiotics are two possible factors which come to mind, but we know of no scientific evidence that these are responsible. There has been a slight decrease in the mean dietary fiber content in the Swedish diet during the last three decades. The decreased incidence of acute appendicitis cannot therefore be correlated with an increase in the mean dietary fiber intake.

Acute Disease↗

PubMed1981

Wheat bran increases high-density-lipoprotein cholesterol in the rat.

1. Five groups of male Sprague Dawley rats were given for 6 months a diet with high protein and fat contents but a very low dietary fibre content (group B), and this diet mixed with (g/kg) 50 low-methoxyl pectin (group L), 50 high-methoxyl pectin (group H), 50 guar gum (group G) and 200 wheat bran (group WB, corresponding to 100 wheat fibre) respectively. 2. The weight increment was significantly lower in group G than in the other groups. Assuming no energy value of the dietary fibre, the weight increment (/kJ) was the same in groups B, L and H, lower in group G and higher in group WB, indicating that a proportion of the bran fibre might in fact be available as a source of energy. 3. Wheat bran increased total plasma cholesterol and high-density-lipoprotein cholesterol after 6, 12 and 26 weeks. Group G had significantly lowered plasma cholesterol after 12 weeks. Pectin on the other hand did not significantly influence total or HDL-cholesterol levels. It is therefore possible that the plasma cholesterol lowering effect of pectin previously demonstrated in the rat is dependent on the presence of significant amounts of dietary cholesterol as our diets did not contain added cholesterol. Plasma triglycerides decreased with age but were similar in all groups.

Animals↗

PubMed1981

Nutrient intake and health status of vegans. Chemical analyses of diets using the duplicate portion sampling technique.

A strict vegetarian diet [vegan diet (VD)] was investigated. Six middle-aged vegans (three men and three women) collected copies of 24-h diets using the duplicate portion sampling technique. By chemical analyses, the nutrient composition was determined in detail and compared with corresponding figures of a normal mixed Swedish diet. In the VD 30% of the energy originated from fat compared with 40% in normal Swedish mixed diet (MD). Linoleic acid was the dominant fatty acid (60% of total fat in VD versus 8% in MD). The VD contained 24 g protein/1000 kcal compared to 30 g/1000 kcal in MD, but the intake of essential amino acids by the vegans exceeded the recommendations. Dietary fiber was about 5 times higher in the vegan diet (29 versus 6 g/1000 kcal) and sucrose similar to MD (18 versus 21 g/1000 kcal). Among the inorganic nutrients the concentration of calcium (351 versus 391 mg/1000 kcal) and sodium (53 versus 49 mmol/1000 kcal) were similar in both types of diets but the amount of potassium (56 versus 30 mmol/1000 kcal, magnesium (300 versus 110 mg/1000 kcal), iron (9 versus 6.5 mg/1000 kcal), zinc (6.5 versus 4.7 mg/1000 kcal), and copper (2 versus 0.7 mg/1000 kcal) were nearly doubled. Iodine (39 versus 156 micrograms/1000 kcal and selenium (5 versus 17 micrograms/1000 kcal) were much lower in the VD, selenium even being undetectable in several 24-h diets. The VD was rich in folic acid (301 versus 90 micrograms/1000 kcal in MD) but the intake of vitamin B12 was only 0.3 to 0.4 microgram/day (MD: 3 to 4 micrograms/day). No clinical signs of nutritional deficiency were observed in the vegans. Serum protein levels of the vegans as well as their serum lipoproteins were near the lower range of the reference group. In addition, none of the vegans was overweight and their blood pressures were low for their age.

Blood Pressure↗