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Biomedical subjects

N G Asp

Publications and source records attributed to N G Asp.

At least 37 records · Page 2Linked to original sources
PubMed1993

Effects of different vegetables in mixed meals on glucose homeostasis and satiety.

Different vegetables--carrots, peas, Brussels sprouts and spinach--were added to a typical Swedish lunch test meal in portions of 96-164 g. The test and the control meals without vegetables were balanced with respect to digestible carbohydrates (59.7 g) and energy (2000 kJ, 475 kcal), and as far as possible also concerning protein and fat. The added vegetables contained 4.4 g dietary fibre. The meals were prepared by microwave heating and served in the morning after an overnight fast to 10 healthy, male volunteers. Postprandial blood glucose, plasma insulin and C-peptide levels were measured at regular intervals until 210 min. The satiety was graded on a simple scale of 1-10. The meal with spinach elicited significantly lower insulin and C-peptide responses than the control meal, but no significant differences in glucose response or satiety were observed. The other vegetables tested showed no significant effects either on glucose and hormonal responses or on satiety.

Adult↗
PubMed1992

Incomplete digestion of legume starches in rats: a study of precooked flours containing retrograded and physically inaccessible starch fractions.

The digestibility of starch in precooked flours from green coat lentils (Lens culinaris Medik) and red kidney beans (Phaseolus vulgaris L.) was investigated by balance experiments using rats treated with antibiotics to suppress hind-gut fermentation. The legume preparations were rich in intact cells filled with denaturated starch and contained retrograded amylose. Between 8% (beans) and 11% (lentils) of the total starch ingested appeared in the feces, indicating a relatively low starch digestibility. Red bean flours of two different particle sizes were similarly digested. Sixty percent of the fecal starch in the bean-fed animals and 70% in the lentil-fed group was retrograded amylose. The in vitro indigestible starch content of the flours was evaluated with three different methods that gave rather different values. The retrograded amylose fraction, measured after alkaline treatment of a dietary fiber residue obtained by enzymic digestion, was quantitatively recovered in the feces. None of the procedures gave accurate estimates of the total in vivo indigestible starch. Fecal excretion of starch in rats not treated with antibiotics indicated that the indigestible starch in lentils was less susceptible to fermentation than that in the red bean preparations.

Animals↗
PubMed1992

Variation in dietary fibre, beta-glucan, starch, protein, fat and hull content of oats grown in Sweden 1987-1989.

Samples of oat groat from cultivars grown in Sweden during 3 years (1987-1989, 50 samples/year) were investigated. On an average, the kernels contained 15.9% protein, 7.0% fat, 9.7% dietary fibre and 63.2% starch (% of dry matter). The coefficient of variation was highest for fat (26%) and lowest for starch (7%). The thousand kernel weight was on average 34.7 g. The content of dietary fibre and fat was significantly negatively correlated and the starch positively correlated with the thousand kernel weight. The samples contained mean (and range) 9.7% (5.0-13.4) total dietary fibre, 3.5% (2.0-5.0) soluble dietary fibre, and 4.6% (3.5-5.7) beta-glucan. The beta-glucan content was significantly positively correlated with insoluble and total dietary fibre as well as with the fat content, and significantly negatively correlated with starch.

Dietary Fiber↗
PubMed1992

[Nutrition education --an important matter in medical education].

At the Nordic Federation of Medical Education congress on nutrition held at Lund in April 1991, it was agreed that nutrition should be allotted adequate space within the framework both of the preclinical and clinical curricula. A proposal was presented whereby a basic course in nutrition would be scheduled early in the general medical curriculum, together with clinical nutrition both integrated with other suitable clinical subjects and as a self-contained subject. The physician's role in a preventive capacity in the public health sector was discussed, as were research aspects of the subject.

Curriculum↗
PubMed1991

Small intestinal peptidases and disaccharidases in rats with acute uremia.

Acute uremia was induced in rats with temporary clamping of the left renal pedicle and contralateral nephrectomy. Jejunal peptidase activities (aminopeptidase N, dipeptidyl peptidase IV and aminopeptidase A), disaccharidase activities (maltase, sucrase, lactase and trehalase) and morphology were studied. A significant (p less than 0.05) increase in aminopeptidase N activity and a positive correlation between aminopeptidase N activity and serum urea was found in the uremic rats. The other peptidase activities showed a slight increase in the uremic rats. A shortening of the microvilli of the small intestinal epithelial cells in the uremic rats was seen by electron microscopy. The disaccharidase activities was unaltered. This study shows the presence of functional alterations in the small intestine in rats with acute uremia. The observations are also compatible with different regulation mechanisms for the brush border peptidases and disaccharidases.

Acute Disease↗
PubMed1990

Fermentation of vegetable fiber in the intestinal tract of rats and effects on fecal bulking and bile acid excretion.

The fermentative breakdown and fecal bulking capacity of dietary fiber from various vegetables (carrots, rutabagas, peas, green beans and Brussels sprouts) were evaluated in balance experiments in rats. The excretion of bile acids, protein and fat was also studied. The addition of blanched vegetables providing 10 g of fiber/100 g of diet caused a two-(rutabagas) to threefold (carrots) increase in fecal dry weight compared to that with a basal fiber-free diet. With green beans and Brussels sprouts, only about 25% of the fecal dry weight could be accounted for as fiber, whereas with the other investigated vegetables, 40-47% was fiber. Of the remaining part, 11% on average was fat, and 18% was crude protein. Fiber in carrots and peas was the least degraded, with approximately 47% of the polysaccharide intake being excreted in feces. By contrast, the breakdown of the fiber in green beans and Brussels sprouts was more extensive, with a mean of 23% of the polysaccharides being recovered. Among individual fiber constituents, glucose, mannose and uronic acids were least fermented, with considerable differences between vegetables. Total excretion of bile acids was reduced only when Brussels sprouts were added, whereas the concentration of fecal bile acids was lowered with all vegetables except rutabagas. However, no uniform change in fecal bile acid pattern could be detected.

Animals↗
PubMed1989

Comparison of glycemic response and insulin requirements after mixed meals of equal carbohydrate content in healthy, type-1, and type-2 diabetic man.

The postprandial insulin requirements after three mixed meals of equal carbohydrate and energy content were assessed in 10 type-1 and 12 type-2 diabetics by a glucose-controlled insulin infusion system. These were compared with the glycemic response to the same meals of 10 healthy individuals (glycemic index). In type-1 diabetics, we found the highest insulin requirements after consumption of a continental breakfast (low fibre, low protein, high fat). Ten percent less insulin was infused after milk (low fat, high protein) and 30% less after an English breakfast (high fibre, high protein). Type-2 diabetics showed no significant differences in insulin requirements between the three test meals. The glycemic response in healthy individuals had no relation to these insulin requirements. Continental and English breakfast had a similar glycemic effect, whereas milk produced only 30% of the blood glucose response observed after the continental breakfast. These results indicate that neither the carbohydrate content (exchange lists) nor the glycemic index enable prediction of postprandial insulin requirements in insulin-deficient diabetes. For this purpose, we propose the insulin-need index, elaborated by testing whole meals in closed-loop experiments with type-1 diabetics.

Adult↗
PubMed1989

Dietary fibre enrichment, blood pressure, lipoprotein profile and gut hormones in NIDDM patients.

The influence of a beet-fibre enriched diet (mean 40 g FibrexR, 27 g dietary fibre per day) on blood pressure, plasma lipoproteins and glycaemic control was studied in 12 non-insulin-dependent diabetic (NIDD) patients. The effect on gastrointestinal hormones was also investigated. Beet-fibre and control diets were given in randomized order for 8 weeks each. During the beet-fibre diet the systolic blood pressure decreased (P less than 0.05) and the HDL-cholesterol levels increased (P less than 0.05) compared to values before the study. There was a tendency for systolic blood pressure to be lower also in the control period, but this was not statistically significant. After both diet periods the total plasma cholesterol and triglyceride levels decreased, as well as the LDL/HDL ratio. Blood glucose levels--fasting or postprandial--and glycosylated haemoglobin were not affected during the two different diet periods. In obese NIDD patients, however, the postprandial insulin levels were lower after the beet-fibre diet compared to the control diet. This subgroup also showed lower fasting values of pancreatic polypeptide and motilin were recorded for the obese patients after the fibre-rich period compared to before the study. Further, increases in postprandial motilin levels, 60-180 min, were found after the fibre-rich period. Investigations with reference to an entero-hormonal mechanism by measuring neurotensin and peptide YY did not show any variations between the diet periods.

Adult↗
PubMed1988

Dietary fiber decreases fasting blood glucose levels and plasma LDL concentration in noninsulin-dependent diabetes mellitus patients.

Realistic high-fiber and regular low-fiber diets were given for 8 wk each to noninsulin-dependent diabetes mellitus (NIDDM) patients whose diabetes was being controlled satisfactorily by diet alone. The purpose of the study was to evaluate the metabolic effects of dietary fiber without changing energy intake or proportions of protein, fat, and carbohydrates. The high-fiber diet induced lower fasting blood glucose levels (p less than 0.01) and decreased the ratio of low-density lipoproteins to high-density lipoproteins (p less than 0.025); no difference was found in HbA1c between the two diet periods. Continuous glucose monitoring also showed a difference in fasting glucose levels that remained after identical low-fiber test meals. The incremental glucose responses did not differ. The fasting and incremental postprandial levels of insulin, C-peptide, glucagon, and somatostatin did not change, whereas the mean triglyceride concentrations were lower after the high-fiber diet. The results suggest a beneficial effect of dietary fiber in the metabolic control of NIDDM.

Aged↗
PubMed1988

Degree of starch gelatinization, digestion rate of starch in vitro, and metabolic response in rats.

Glycemic response after ingestion of starchy foods varies. Starch in many common ready-to-eat foods is only partly gelatinized. In view of this, the relationships among degree of starch gelatinization, in vitro digestion rate, and in vivo metabolic response in rats were studied. Wheat starch with different degrees of gelatinization was used in the experiments. Plasma glucose and insulin responses as well as the rate of in vitro hydrolysis with alpha-amylase were strongly correlated to the degree of starch gelatinization (r = 0.88, r = 0.90, and r = 0.96, respectively). Plasma glucose and insulin responses were also positively correlated to the rate of hydrolysis with alpha-amylase in vitro (r = 0.98 and r = 0.76, respectively). These results suggest that the degree of starch gelatinization is an important determinant both for the rate of starch hydrolysis in vitro and for the metabolic response in vivo.

Animals↗
PubMed1988

Fermentation of oat fiber in the rat intestinal tract: a study of different cellular areas.

Intestinal fermentation of dietary fiber from oat husk, bran, and white flour and a commercial oat bran was investigated through balance experiments in rats. Both solubility and monomeric composition of the fiber differed widely. Fiber from husk was only 0.5% soluble and nearly completely resistant to fermentation whereas fiber from bran (38% soluble) and white flour (24% soluble) was more fermentable (62% and 55% of the intake, respectively). Fiber from commercial bran (37% soluble) was most extensively fermented; only 19% of the fiber could be detected in feces. The fecal dry weight with the husk in the diet was significantly (p less than 0.001) higher than that for the other preparations. Most of the fecal dry weight increment for husk (approximately 95%) could be accounted for as fiber whereas only 45-65% of the increment was undergraded fiber for the other preparations. An additional 20-30% could be explained by protein and approximately 15% by fat with these preparations.

Animals↗
PubMed1988

Effects of four meals with different kinds of dietary fibre on glucose metabolism in healthy subjects and non-insulin-dependent diabetic patients.

The effects of four mixed meals on glucose metabolism were studied during a 4-h period in 12 healthy women and in 13 women with non-insulin-dependent diabetes. Three test meals containing different types of dietary fibre in realistic amounts (cereal, leguminous and mixed-fibre), and one control meal were prepared. Each meal was calculated to contain 2.1 MJ (500 kcal) and the energy distributions of protein, fat and carbohydrate (by difference) were 15, 29-31 and 56-58 per cent, respectively. Results of analyses of the mixed meals, performed after the clinical study, showed unexpectedly large deviations from the calculated values regarding digestible carbohydrates in the leguminous meal. In the healthy group the blood glucose concentrations after the four meals did not differ significantly. In the diabetic group the area under the curve of blood glucose values was significantly smaller after both the leguminous meal and that containing mixed dietary fibre than after the control meal (P less than 0.001). There were also significant differences in blood glucose between the cereal meal and the leguminous and mixed-fibre meals (P less than 0.001), and between the leguminous meal and the mixed-fibre meal (P less than 0.05). In the healthy group the insulin response was significantly lower after the leguminous meal than after the control meal (P less than 0.05) whilst the diabetic group showed lower insulin responses after all the high-fibre test meals. Serum triglycerides, cholesterol and HDL cholesterol were similar after the different meals. The lower content of digestible carbohydrates, especially in the leguminous meal, complicates the interpretation of the results.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1987

Dietary fibre--definition, chemistry and analytical determination.

Dietary fibre includes non-starch polysaccharides and lignin that are not digested or absorbed in the human small intestine. It contains a mixture of chemically complex polysaccharides. Lignin is a highly cross-linked complex polymer of phenylpropane units. The plant cell wall is the main source of dietary fibre and its structure is reviewed briefly. The structure of the main dietary fibre polysaccharides is then summarized. The demarcation between starch--the main digestible polysaccharide--and dietary fibre presents some problems due to more or less enzyme resistant starch fractions that occur naturally or are formed with processing. "Resistant starch" formed during baking passes through the small intestine in the rat and, probably, in man and is fermented in the colon. It should therefore also be regarded as dietary fibre. Methods for dietary fibre determination fall into two categories: gravimetric methods, weighing the dietary fibre after removal of other components; component analysis methods, determining monomeric composition of fibre polysaccharides (preferably by gas-liquid chromatography) supplemented with a gravimetric lignin determination and separate assay of uronic acid components (pectin). Recently developed enzymatic gravimetric methods are most convenient for the assay of total dietary fibre or water soluble and insoluble fibre separately, whereas component analysis is required for determining the dietary fibre composition.

Chemical Phenomena↗
PubMed1987

Definition and analysis of dietary fibre.

The definition of dietary fibre as "non-starch polysaccharides plus lignin", that has now been widely accepted, is chemically more distinct than earlier definitions, but still implies some difficulties in its demarcation. In practice, analytical problems and limitations are important, since definition and analysis of dietary fibre are closely related. The delimitation towards more or less undigestible starch fractions, highly soluble polysaccharides, oligosaccharides, and undigestible protein is discussed, as well as phytate, tannins and some other components. Methods for analysis of dietary fibre are based on one or more of three different principles: 1) Weighing after removal of non-fibre components, 2) Colorimetric carbohydrate determinations 3) Specific determination of monomeric constituents by gas-liquid chromatography (GLC) or high performance liquid chromatography (HPLC). Gravimetric methods, using enzymatic degradation of protein and starch, are generally preferred for assay of total dietary fibre, or soluble and insoluble fibre separately. Colorimetric methods are used mainly for determining uronic acids as a measure of pectins. Detailed methods usually employ GLC determination of monomers after acid hydrolysis, but HPLC appear to develop as a convenient alternative. Uronic acids are determined separately by colorimetry or decarboxylation, and lignin usually as Klason lignin, i.e. acid insoluble material.

Chromatography, Gas↗