Glycaemic glucose equivalent: combining carbohydrate content, quantity and glycaemic index of foods for precision in glycaemia management.
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The glycaemic index (GI) is the blood glucose response to carbohydrate in a food as a percentage of the response to an equal weight of glucose. Because GI is a percentage, it is not related quantitatively to food intakes, and because it is based on equi-carbohydrate comparisons, GI-based exchanges for control of glycaemia should be restricted to foods providing equal carbohydrate doses. To overcome these limitations of GI, the glycaemic glucose equivalent (GGE), the weight of glucose having the same glycaemic impact as a given weight of food, is proposed as a practical measure of relative glycaemic impact. To illustrate the differences between GGE and GI in quantitative management of postprandial glycaemia, published values for carbohydrate content, GI and serving size of foods in the food groupings, breads, breakfast cereals, pulses, fruit and vegetables, were used to determine the GGE content per equal weight and per serving of foods. Food rankings and classifications for exchanges based on GGE content were compared with those based on GI. In all of the food groupings analysed, values for relative glycaemic impact (as GGE per 100 g food and per serving) within each of the categories, low, medium and high GI were too scattered for GI to be a reliable indicator of the glycaemic impact of any given food. Correlations between GI and GGE content per serving were highest in food groupings of similar carbohydrate content and serving size, including breads (r = 0.73) and breakfast cereals (r = 0.8), but low in more varied groups including pulses (r = 0.66), fruit (r = 0.48) and vegetables (r = 0.28). Because of the non-correspondence of GI and GGE content, food rankings by GI did not agree with rankings by GGE content, and placement of foods in GI-based food exchange categories was often not appropriate for managing glycaemia. Effects of meal composition and food intake on relative glycaemic impact could be represented by GGE content, but not by GI. Because GGE is not restricted to equicarbohydrate comparisons, and is a function of food quantity, GGE may be applied, irrespective of food or meal composition and weight, and in a number of approaches to the management of glycaemia. Accurate control of postprandial glycaemia should therefore be achievable using GGE because they address the need to combine GI with carbohydrate dose in diets of varying composition and intake, to obtain a realistic indication of relative glycaemic impact. (+info)
Inverse association between the effect of carbohydrates on blood glucose and subsequent short-term food intake in young men.
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BACKGROUND: A primary mechanism by which carbohydrates are thought to regulate satiety and food intake is through their effect on blood glucose. OBJECTIVES: The objectives were to describe the effect of defined carbohydrate preloads on food intake and blood glucose and to determine the association between food intake and blood glucose. DESIGN: Three experiments were conducted in which selected carbohydrates as 1255-kJ isovolumetric beverages were administered to young men after an overnight fast. Measurements of blood glucose and appetite were made at specified times during the next 60 min. Food intake was measured at 60 min. RESULTS: Glucose resulted in the highest glycemic response, which was followed, in order, by the responses to polycose, sucrose, amylopectin, a fructose-glucose mixture, and amylose. The high-glycemic-index preloads (glucose, polycose, and sucrose) resulted in lower mealtime energy intake during a test meal at 1 h, but the low-glycemic-index preloads (amylose, amylopectin, and a fructose-glucose mixture) did not. An inverse relation was observed between the blood glucose concentrations in the area under the curve and the subjective appetite (r = -0.23, P < 0.05) and food intake at 60 min (r = -0.24, P < 0.05). CONCLUSIONS: Food intake and subjective appetite are inversely associated with blood glucose response in the 60 min after consumption of carbohydrates. Carbohydrates with a high glycemic index (glucose, polycose, and sucrose) suppress subjective appetite and food intake in the short term, but those with a low glycemic index (amylose and amylopectin) do not. (+info)
Glycemic index in chronic disease: a review.
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AIM: The intent of this review is to critically analyze the scientific evidence on the role of the glycemic index in chronic Western disease and to discuss the utility of the glycemic index in the prevention and management of these disease states. BACKGROUND: The glycemic index ranks foods based on their postprandial blood glucose response. Hyperinsulinemia and insulin resistance, as well as their determinants (eg high energy intake, obesity, lack of physical activity) have been implicated in the etiology of diabetes, coronary heart disease and cancer. Recently, among dietary factors, carbohydrates have attracted much attention as a significant culprit, however, different types of carbohydrate produce varying glycemic and insulinemic responses. Low glycemic index foods, characterized by slowly absorbed carbohydrates, have been shown in some studies to produce beneficial effects on glucose control, hyperinsulinemia, insulin resistance, blood lipids and satiety. METHOD: Studies on the short and long-term metabolic effects of diets with different glycemic indices will be presented and discussed. The review will focus primarily on clinical and epidemiological data, and will briefly discuss in vitro and animal studies related to possible mechanisms by which the glycemic index may influence chronic disease. (+info)
Dietary glycemic index, glycemic load and ovarian cancer risk: a case-control study in Italy.
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BACKGROUND: Dietary carbohydrates vary in their ability to raise blood glucose and insulin levels, which, in turn, influence levels of sex hormones and insulin-like growth factors. We analyzed the effect of type and amount of carbohydrates on ovarian cancer risk, using the glycemic index (GI) and the glycemic load (GL) measurement in a large case-control study conducted in Italy. MATERIALS AND METHODS: Cases included 1031 women with incident, histologically confirmed epithelial ovarian cancer, from four Italian regions. Controls included 2411 women admitted to the same hospital networks for acute, non-neoplastic conditions. Average daily GI and GL were calculated from a validated food frequency questionnaire. Odds ratios (OR) and the corresponding 95% confidence intervals (CI) were computed using multiple logistic regression. RESULTS: Ovarian cancer was directly associated with dietary GI (OR for highest versus lowest quartile = 1.7, 95% CI 1.3-2.1) and GL (OR = 1.7, 95% CI 1.3-2.1). The associations were observed in pre- and postmenopausal women, and they remained consistent across strata of major covariates identified. CONCLUSIONS: This study supports the hypothesis of a direct association between GI and GL and ovarian cancer risk and, consequently, of a possible role of hyperinsulinemia/insulin resistance in ovarian cancer development. (+info)
Dietary and lifestyle interventions in the management of the metabolic syndrome: present status and future perspective.
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OBJECTIVE: To review the mechanisms underlying the metabolic syndrome, or syndrome X, in humans, and to delineate dietary and environmental strategies for its prevention. DESIGN: Review of selected papers of the literature. RESULTS: Hyperinsulinemia and insulin resistance play a key role in the development of the metabolic syndrome. Strategies aimed at reducing insulin resistance may be effective in improving the metabolic syndrome. They include low saturated fat intake, consumption of low-glycemic-index foods, physical exercise and prevention of obesity. CONCLUSIONS: Future research, in particular the genetic basis of the metabolic syndrome and the interorgan interactions responsible for insulin resistance, is needed to improve therapeutic strategies for the metabolic syndrome. (+info)
Effect of low-glycemic-index dietary advice on dietary quality and food choice in children with type 1 diabetes.
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BACKGROUND: The practicality of diets with a low glycemic index (GI) is controversial. Theoretically, low-GI diets may limit food choice and increase dietary fat intake, but there is little objective evidence to support such a theory. OBJECTIVE: The objective was to determine the effect of low-GI dietary advice on dietary quality and food choice in children with diabetes. DESIGN: Children aged 8-13 y with type 1 diabetes (n = 104) were recruited to a prospective, randomized study comparing the effects of traditional carbohydrate-exchange dietary advice (CHOx) with those of more flexible low-GI dietary advice (LowGI). We determined the effect on long-term macronutrient intake and food choice with the use of 3-d food diaries. RESULTS: There were no differences in reported macronutrient intakes during any of the recording periods. After 12 mo, intakes of dietary fat (33.5 +/- 5.6% and 34.2 +/- 6.7% of energy, P = 0.65), carbohydrate (48.8 +/- 5.4% and 48.6 +/- 6.5% of energy, P = 0.86), protein (17.6 +/- 2.5% and 17.3 +/- 3.7% of energy, P = 0.61), total sugars, and fiber did not differ significantly between the CHOx and LowGI groups, respectively. The average number of different carbohydrate food choices per day also did not differ significantly. Subjects in the lowest-GI quartile consumed less carbohydrate as potato and white bread, but more carbohydrate as dairy-based foods and whole-grain breads than did subjects in the highest-GI quartile. CONCLUSION: Children with diabetes who receive low-GI dietary advice do not report more limited food choices or a diet with worse macronutrient composition than do children who consume a traditional carbohydrate-exchange diet. (+info)
Evaluation of autofluorescent property of hemoglobin-advanced glycation end product as a long-term glycemic index of diabetes.
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Current methods for measuring long-term glycemia in patients with diabetes are HbA(1c) and advanced glycation end products (AGEs), which are estimated by phenyl boronate affinity chromatography and competitive enzyme-linked immunosorbent assay, respectively. In this study, we hypothesize that the intrinsic fluorescence property of hemoglobin-AGE (Hb-AGE) may be a simple, accurate, and therefore better index for long-term glycemic status due to its highly specific nature and longer half-life. To establish this contention, in vitro and in vivo experiments were carried out. The former was performed by incubating commercially available hemoglobin with 5 and 20 mmol/l glucose and the latter through experimentally induced (streptozotocin) diabetes in an animal model (male Wistar rats) to identify the new fluorophore formed due to the nonenzymatic glycosylation of hemoglobin. An adduct exhibiting fluorescence at 308/345 nm of excitation/emission wavelengths has been identified and its time-dependent formation established. Under in vitro conditions, the first appearance of the new fluorophore was noticed only after a period of 2 months, whereas under in vivo conditions, it increased significantly after 2 months of hyperglycemia. Consistent with the observations, studies on patients with type 2 diabetes demonstrated an elevated level of this new fluorescent adduct in patients with persisting high levels of plasma glucose for >2 months. Based on the results obtained, Hb-AGE appears to be an efficient fluorescence-based biosensing molecule for the long-term monitoring of glycemic control in diabetes. (+info)
The starch from Solanum lycocarpum St. Hill. fruit is not a hypoglycemic agent.
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We have investigated the hypoglycemic effect induced by the starch obtained from the unripe fruits of Solanum lycocarpum (Solanaceae). Per os administration of the starch (1000 or 2000 mg/kg, twice daily for 7 days, N = 6) did not change glycemia levels of nondiabetic female Swiss mice weighing 25-30 g. In streptozotocin-induced diabetic mice, similar treatment with the starch did not change the elevated glycemia 3 h after the last dose (diabetic treated with saline = 288 17/309 18; starch 1000 mg/kg = 295 +/- 33; starch 2000 mg/kg = 258 +/- 37; N = 5). In animals fasted for 15 h, per os administration of glucose (600 mg/kg) significantly increased glycemia 1 h later. Previous (-30 min) treatment of the animals with the starch (1000 or 2000 mg/kg; N = 5) did not change the increase of glycemia. Per os administration of the starch (1000 or 2000 mg kg-1 day-1, twice daily for 7 days) did not induce body weight gain or loss. The chemical analysis of the starch indicated the presence of glycoalkaloids, a finding that represents a reason for concern since many of these substances are generally toxic. In interviews with 56 diabetic patients, 29 medicinal plants were reported as useful in their treatment of diabetes and S. lycocarpum was the sixth most frequently mentioned. All patients interviewed reported that they also used insulin or oral hypoglycemic drugs. The results of the present study do not provide evidence for a hypoglycemic effect associated with the polysaccharide fraction of S. lycocarpum in either normal or hyperglycemic mice. These data demonstrate the need for adequate pharmacological investigation of the natural products widely used in folk medicine. (+info)