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Biomedical subjects

A L Jenkins

Publications and source records attributed to A L Jenkins.

72 records · Page 4Linked to original sources
PubMed1984

Slowly digested carbohydrate food improves impaired carbohydrate tolerance in patients with cirrhosis.

To test whether impaired carbohydrate tolerance in cirrhosis could be modified by dietary means ten cirrhotic patients, five of them taking insulin, took as breakfast either lentils or wholemeal bread and cottage cheese containing the same amount of carbohydrate and protein. Lentils resulted in significantly diminished blood glucose, insulin (in those not on insulin) and gastric inhibitory peptide responses. Enteroglucagon and neutrotensin levels were high with lentils, suggesting that absorption of lentil carbohydrate continued into the ileum with perhaps some malabsorption, so confirming the results of earlier studies in vitro. However, breath hydrogen studies on a separate group of eight healthy volunteers indicated that the difference in carbohydrate malabsorption between lentil, and wholemeal bread was insignificant. It is suggested that slowly digested carbohydrate foods, such as leguminous seeds, may minimize carbohydrate intolerance in patients with cirrhosis.

Blood Glucose↗
PubMed1984

Relationship between polyphenol intake and blood glucose response of normal and diabetic individuals.

Five leguminous and eight nonleguminous foods were analyzed for polyphenol concentration by the Prussian Blue and the Folin Denis methods and correlated with blood glucose response (glycemic index) in normal or diabetic volunteers. Polyphenol concentrations and intakes per 50 g available carbohydrate portions were higher in the leguminous foods than those in the nonleguminous foods. In both normal and diabetic individuals, a negative correlation was observed between glycemic index and the concentration or total intake of polyphenols. Polyphenols, especially the large polymeric type or condensed tannins, appear to be responsible in part for the reduced glycemic response to carbohydrate foods and in part to lower blood glucose response to legumes compared with cereal products.

Blood Glucose↗
PubMed1984

The relationship between glycemic response, digestibility, and factors influencing the dietary habits of diabetics.

A significant relationship was found between the rate of release of the sugars; glucose, maltose, and maltotriose from amylitic digestion of 10 foods tested in vitro (expressed as the digestibility index) and the blood glucose response to 50-g carbohydrate portions of the same foods eaten by diabetics (expressed as the glycemic index), (r = 0.815, n = 10, p greater than 0.01). The glycemic index related to both the palatability of the foods (r = 0.731, p less than 0.05) and their frequency of use (r = 0.698, p less than 0.05). However, in this group of motivated diabetics food use was not related directly to palatability, but rather to health belief (r = 0.689, p less than 0.05). The results suggest that carbohydrate foods of potential use to the diabetic may be identified by their in vitro digestion characteristics but to a large extent their acceptance will depend on health belief and possibly ease of preparation.

Aged↗
PubMed1983

The glycaemic index of foods tested in diabetic patients: a new basis for carbohydrate exchange favouring the use of legumes.

Recently diabetic patients have been encouraged to increase their carbohydrate intake, but exact details of which foods to use are lacking. To determine whether sufficiently large differences existed to justify more specific dietary advice, we compared the glycaemic responses to 50 g carbohydrate portions of different foods, taken as breakfast test meals by groups of five to seven diabetic patients. Two- to threefold differences were seen amongst the 15 foods tested. The glycaemic responses for spaghetti, 'All-bran', rice and beans were significantly below those for bread, while 'Cornflakes' were above. Factors predicted to influence this were without effect, including: substituting wholemeal for white bread, increasing substantially the simple sugars (using 'All-bran' or bananas instead of wholemeal bread) and doubling meal protein by adding cottage cheese to bread. Paired comparisons of the glycaemic response to the five legumes with those of the seven other starchy foods (breads, spaghetti, rice, Cornflakes, oatmeal porridge and potatoes) showed that the mean peak rise in blood glucose concentration and mean area under the glucose curve after beans were 23 and 28% lower, respectively, than the mean for the other foods (p less than 0.001). Such results suggest a potentially valuable role for dried leguminous seeds in carbohydrate exchanges for individuals with impaired carbohydrate tolerance. These large differences in blood glucose response to different food cannot at present be predicted directly from tables of chemical composition. Nevertheless, physiological testing may both aid in understanding the factors responsible and help selection of the appropriate carbohydrate foods for the diabetic diet.

Aged↗
PubMed1983

Rapid species identification and biotyping of respiratory isolates of Haemophilus spp.

Three commercially available systems, the 4-h Minitek Enterobacteriaceae III, the Haemophilus Trio-Tube, and the Micro-ID, were evaluated for their capacities to identify and biotype 308 respiratory isolates of Haemophilus spp. When compared with aminolevulinic acid test results, the definitive identification method used in this study, these systems demonstrated no significant differences in their capacities to differentiate Haemophilus influenzae from Haemophilus parainfluenzae. They were in agreement with the standard method of species identification approximately 50% of the time. When sucrose was added to the Minitek and Trio-Tube configurations, the efficiency rate of species identification increased to more than 95%. The Micro-ID could not be modified to incorporate this additional biochemical parameter. The performance of the sucrose-supplemented Minitek and Trio-Tube systems, compared to the combined results of Micro-ID and aminolevulinic acid, produced correlations of 94 and 90%, respectively. Rapid and accurate methodologies are available for combined species identification and biotyping of Haemophilus spp.

Haemophilus↗
PubMed1982

Relationship between rate of digestion of foods and post-prandial glycaemia.

The amount of carbohydrate released at 1 and 5 h by digestion in vitro of 2 g carbohydrate portions of 14 foods by human digestive juices was compared with the area under the 2-h blood glucose response curve when 50 g carbohydrate portions were fed to groups of five to ten healthy volunteers. A significant relationship was found between the amounts of sugars and oligosaccharides liberated at 1 and 5 h and the food blood glucose area expressed as a percentage of the blood glucose area for 50 g glucose (r = 0.8627 and 0.8618, p less than 0.001). A significant relationship was also found between the glycaemic index and the food fibre content (p less than 0.02) and between the glycaemic index and the glucose trapping capacity of the foods (p less than 0.05). Legumes as a group liberated 56% less sugars and oligosaccharides (p less than 0.01) than the eight cereal foods over 5 h. It is suggested that such studies in vitro may help to identify food of use for diabetic patients, and at the same time throw further light on factors which affect post-prandial glycaemia.

Adult↗
PubMed1981

Glycemic index of foods: a physiological basis for carbohydrate exchange.

The determine the effect of different foods on the blood glucose, 62 commonly eaten foods and sugars were fed individually to groups of 5 to 10 healthy fasting volunteers. Blood glucose levels were measured over 2 h, and expressed as a percentage of the area under the glucose response curve when the same amount of carbohydrate was taken as glucose. The largest rises were seen with vegetables (70 +/- 5%), followed by breakfast cereals (65 +/- 5%), cereals and biscuits (60 +/- 3%), fruit (50 +/- 5%), dairy products (35 +/- 1%), and dried legumes (31 +/- 3%). A significant negative relationship was seen between fat (p less than 0.01) and protein (p less than 0.001) and postprandial glucose rise but not with fiber or sugar content.

Adult↗
PubMed1980

Effect of guar crispbread with cereal products and leguminous seeds on blood glucose concentrations of diabetics.

To compare the effect on blood glucose concentrations of guar incorporated into crispbreads with that of unprocessed high-fibre foods groups of four to six diabetics took a total of seven test breakfasts on separate days. By comparison with a breakfast of wholemeal bread and cheese, guar crispbread combined with bread reduced the area under the glucose response curve to 51% (p < 0.05); bread and soya beans reduced the area to 65% (p < 0.05); guar crispbread with soya beans to 25% (p < 0.002); and soya beans with lentils to 29% (p < 0.002). Porridge and cornflake breakfasts showed no difference. The favourable results with leguminous seeds may not make such meals more acceptable than meals of guar products, but a combination of leguminous seeds and guar may allow smaller and more acceptable amounts of both to be used.

Adult↗
PubMed1980

Rate of digestion of foods and postprandial glycaemia in normal and diabetic subjects.

Carbohydrate portions (2 g) of lentils, soya beans, and wholemeal bread were incubated for three hours with human digestive juices and the effect of digestibility on blood glucose examined. Lentils and soya beans released only 39% and 8% respectively of the sugars and oligosaccharides liberated from bread. In healthy volunteers 50 g carbohydrate portions of cooked lentils and soya beans raised blood glucose concentrations by only 42% (p < 0.001) and 14% (p < 0.001) of the bread value. There was a similar response in diabetics. These results suggest that rate of digestion might be a important factor determining the rise in blood glucose concentration after a meal and that supplementing chemical analysis with in-vitro and in-vivo food testing might permit identification of especially useful foods for diabetics.

Adult↗
PubMed1980

Dietary fiber and blood lipids: treatment of hypercholesterolemia with guar crispbread.

Eleven hyperlipidemic patients took an average of 13 g guar in crispbread form over 2- to 8-week periods. Eight weeks' treatment (seven patients) reduced total serum cholesterol by 13% (P less than 0.002) while high-density lipoprotein cholesterol was unchanged. A 13% nonsignificant reduction was also seen in serum triglyceride. Comparison of blood lipid changes over 2-week periods showed guar crispbread to be as effective as guar given in hydrated (eight patients) or semihydrated form (four patients). In addition total serum cholesterol was lowered significantly (11%, P less than 0.05) in five patients where cholestyramine was ineffective. Due to its acceptability, guar crispbread is likely to prove a useful cholesterol-lowering agent.

Adult↗
PubMedDate not supplied

American ginseng improves glycemia in individuals with normal glucose tolerance: effect of dose and time escalation.

OBJECTIVE: We studied the effect of escalating the dose and administration time of American ginseng (AG, Panax quinquefolius L.) in nondiabetic individuals to achieve further improvements in glucose tolerance seen previously when 3 g of AG was taken 40 minutes before a 25 g glucose challenge. METHODS: Ten nondiabetic individuals (6M:4F; mean +/- STD: age = 41 +/- 13 years, BMI = 24.8 +/- 3.5 kg/m2, FBG = 4.5 +/- 0.1 mmol L(-1)) on 12 separate occasions, randomly received 0 (placebo), 3, 6 or 9 g of ground AG root at 40, 80, or 120 minutes before a 25 g oral glucose challenge. Capillary blood glucose was measured prior to ingestion of AG or placebo capsules and at 0, 15, 30, 45, 60 and 90 minutes from start of challenge. RESULTS: Compared with the placebo, 3, 6 and 9 g of AG reduced (p<0.05) postprandial incremental glucose at 30, 45 and 60 minutes; also, 3 and 9 g of AG did so at 90 minutes. At 60 minutes, 9 g of AG reduced incremental postprandial glucose relative to 3 g of AG (p<0.05). All AG doses reduced (p<0.05) area under the incremental glucose curve (3 g, 26.6%; 6 g, 29.3%; 9 g, 38.5%). AG taken at different times did not have an additional influence on postprandial glycemia. CONCLUSIONS: In nondiabetic individuals, 3, 6 or 9 g of AG taken 40, 80 or 120 minutes before a glucose challenge similarly improved glucose tolerance.

Adult↗
PubMedDate not supplied

Glycemic response to wheat products: reduced response to pasta but no effect of fiber.

The blood glucose response to feeding 50-g carbohydrate portions of white and wholemeal bread and white spaghetti was studied in a group of nine diabetic subjects. Blood glucose rises after white and wholemeal bread were identical, but the response after spaghetti was markedly reduced. These results emphasize that food form rather than fiber may be important in determining the glycemic response and that pasta may be a useful source of carbohydrate in the diabetic diet.

Aged↗
PubMedDate not supplied

Glycemic response to pasta: effect of surface area, degree of cooking, and protein enrichment.

To see whether food form, the degree of cooking, or protein enrichment affected the glycemic response to pasta, we gave test-meal breakfasts to 13 diabetic patients. Macaroni had a significantly greater glycemic index (GI) (68 +/- 8) than spaghetti (45 +/- 6, P less than .01); the GI of star pastina was intermediate (54 +/- 6). The GI of spaghetti was not significantly affected by cooking for 5 or 15 min (45 +/- 6 and 46 +/- 5, respectively), or by protein enrichment (38 +/- 4). The GI of spaghetti was similar in 11 non-insulin-dependent and 6 insulin-dependent diabetic patients (49 +/- 7 compared with 57 +/- 8). We conclude that different types of pasta may produce different glycemic responses but that these are not necessarily related to differences in cooking or surface area.

Blood Glucose↗