Impact of postprandial glycaemia on health and prevention of disease

Noodles Made from High Amylose Wheat Flour Attenuate Postprandial Glycaemia in Healthy Adults

Previous research has not considered the effect of high amylose wheat noodles on postprandial glycaemia. The aim of the study is to investigate the effect of consumption of high amylose noodles on postprandial glycaemia over 2-h periods by monitoring changes in blood glucose concentration and calculating the total area under the blood glucose concentration curve. Twelve healthy young adults were recruited to a repeated measure randomised, single-blinded crossover trial to compare the effect of consuming noodles (180 g) containing 15%, 20% and 45% amylose on postprandial glycaemia. Fasting blood glucose concentrations were taken via finger-prick blood samples. Postprandial blood glucose concentrations were taken at 15, 30, 45, 60, 90 and 120 min. Subjects consuming high amylose noodles made with flour containing 45% amylose had significantly lower blood glucose concentration at 15, 30 and 45 min (5.5 ± 0.11, 6.1 ± 0.11 and 5.6 ± 0.11 mmol/L; p = 0.01) compared to subjects consuming low amylose noodles with 15% amylose (5.8 ± 0.12, 6.6 ± 0.12 and 5.9 ± 0.12 mmol/L). The total area under the blood glucose concentration curve after consumption of high amylose noodles with 45% amylose was 640.4 ± 9.49 mmol/L/min, 3.4% lower than consumption of low amylose noodles with 15% amylose (662.9 ± 9.49 mmol/L/min), p = 0.021. Noodles made from high amylose wheat flour attenuate postprandial glycaemia in healthy young adults, as characterised by the significantly lower blood glucose concentration and a 3.4% reduction in glycaemic response.

The effect of 8 plant extracts and combinations on post-prandial blood glucose and insulin responses in healthy adults: a randomized controlled trial

BACKGROUND

Lower post-prandial glucose (PPG) and insulin (PPI) responses to foods are associated with reduced diabetes risk and progression. Several plant extracts have been proposed to reduce PPG or PPI by inhibiting enzymes or transporters involved in carbohydrate digestion and uptake. This study evaluates a range of such extracts, consumed with a carbohydrate load, for their effects on PPG, PPI and indicators of (gastrointestinal) tolerance.

METHODS

Interventions were extracts of mulberry fruit (MFE, 1.5 g), mulberry leaf (MLE, 1.0 g), white bean (WBE, 3.0 g), apple (AE, 2.0 g), elderberry (EE, 2.0 g), turmeric (TE, 0.18 g), AE + TE, and EE + TE. Each of these 8 individual extracts or combinations were added to a rice porridge containing ~ 50 g available carbohydrate (control). In a within-subject (randomised, balanced incomplete block) design, individual subjects received the control and a subset of 4 of the 8 extracts or combinations. Participants were 72 apparently healthy adults (mean [SD] age 31.2 [5.5] yr, body mass index 22.1 [2.0] kg/m2). The primary outcome was the percentage change in 2-h PPG (positive incremental area under the curve) relative to control. Secondary measures were the 2-h PPI response, 7-h breath hydrogen, measures of gastrointestinal discomfort, and urine glucose.

RESULTS

In the 65 subjects who completed the control and at least one intervention treatment, additions of AE, MFE and MLE produced statistically significant reductions in PPG vs control (p < 0.05; mean effect - 24.1 to - 38.1%). All extracts and combinations except TE and WBE significantly reduced PPI (p < 0.01; mean effect - 17.3% to - 30.4%). Rises in breath hydrogen > 10 ppm were infrequent, but statistically more frequent than control only for MLE (p = 0.02). Scores for gastrointestinal discomfort were extremely low and not different from control for any treatment, and no glucosuria was observed.

CONCLUSIONS

Additions of AE, MFE and MLE to rice robustly reduced PPG and PPI. EE significantly reduced only PPI, while TE and WBE showed no significant efficacy for PPG or PPI. Breath hydrogen responses to MLE suggest possible carbohydrate malabsorption at the dose used, but there were no explicit indications of intolerance to any of the extracts.

TRIAL REGISTRATION

ClinicalTrials.gov identifier NCT04258501. Registered 6 February 2020 - Retrospectively registered.

The Effect of Vitamin D Supplementation on Insulin Sensitivity: A Systematic Review and Meta-analysis

BACKGROUND

Vitamin D has been suggested to affect peripheral insulin sensitivity. Evidence regarding the effect of vitamin D supplementation on insulin sensitivity is still conflicting.

PURPOSE

This meta-analysis aimed to assess the effect of vitamin D supplementation on insulin sensitivity in humans with or at risk for insulin resistance.

DATA SOURCES AND STUDY SELECTION

PubMed, Web of Science, Embase, CINAHL, and Cochrane Library were systematically searched for randomized controlled trials (RCTs) from 1980 until 31 December 2018 reporting treatment effects of vitamin D supplementation on insulin sensitivity.

DATA EXTRACTION

The main outcome of interest was the change in insulin sensitivity, derived from the gold standard hyperinsulinemic-euglycemic clamp or the Matsuda index derived from the oral glucose tolerance test and insulin sensitivity index from intravenous glucose tolerance test. We extracted data on the standardized mean difference between the vitamin D treatment and placebo groups in change from baseline insulin sensitivity.

DATA SYNTHESIS

Eighteen RCTs were included in this meta-analysis comparing vitamin D supplementation (n = 612) with placebo (n = 608). Vitamin D supplementation had no effect on insulin sensitivity (standardized mean difference -0.01, 95% CI -0.12, 0.10; P = 0.87, I ² = 0%). Visual inspection of funnel plot symmetry did not suggest potential publication bias.

LIMITATIONS

The number of individuals who participated in the included studies was relatively small, possibly due to the invasive character of the measurement (e.g., clamp).

CONCLUSIONS

This meta-analysis provides no evidence that vitamin D supplementation has a beneficial effect on peripheral insulin sensitivity in people with or at risk for insulin resistance.

Human postprandial responses to food and potential for precision nutrition

Metabolic responses to food influence risk of cardiometabolic disease, but large-scale high-resolution studies are lacking. We recruited n = 1,002 twins and unrelated healthy adults in the United Kingdom to the PREDICT 1 study and assessed postprandial metabolic responses in a clinical setting and at home. We observed large inter-individual variability (as measured by the population coefficient of variation (s.d./mean, %)) in postprandial responses of blood triglyceride (103%), glucose (68%) and insulin (59%) following identical meals. Person-specific factors, such as gut microbiome, had a greater influence (7.1% of variance) than did meal macronutrients (3.6%) for postprandial lipemia, but not for postprandial glycemia (6.0% and 15.4%, respectively); genetic variants had a modest impact on predictions (9.5% for glucose, 0.8% for triglyceride, 0.2% for C-peptide). Findings were independently validated in a US cohort (n = 100 people). We developed a machine-learning model that predicted both triglyceride (r = 0.47) and glycemic (r = 0.77) responses to food intake. These findings may be informative for developing personalized diet strategies. The ClinicalTrials.gov registration identifier is NCT03479866.

Potential Markers of Dietary Glycemic Exposures for Sustained Dietary Interventions in Populations without Diabetes

There is considerable interest in dietary and other approaches to maintaining blood glucose concentrations within the normal range and minimizing exposure to postprandial hyperglycemic excursions. The accepted marker to evaluate the sustained maintenance of normal blood glucose concentrations is glycated hemoglobin A1c (HbA1c). However, although this is used in clinical practice to monitor glycemic control in patients with diabetes, it has a number of drawbacks as a marker of efficacy of dietary interventions that might beneficially affect glycemic control in people without diabetes. Other markers that reflect shorter-term glycemic exposures have been studied and proposed, but consensus on the use and relevance of these markers is lacking. We have carried out a systematic search for studies that have tested the responsiveness of 6 possible alternatives to HbA1c as markers of sustained variation in glycemic exposures and thus their potential applicability for use in dietary intervention trials in subjects without diabetes: 1,5-anhydroglucitol (1,5-AG), dicarbonyl stress, fructosamine, glycated albumin (GA), advanced glycated end products (AGEs), and metabolomic profiles. The results suggest that GA may be the most promising for this purpose, but values may be confounded by effects of fat mass. 1,5-AG and fructosamine are probably not sensitive enough to the range of variation in glycemic exposures observed in healthy individuals. Use of measures based on dicarbonyls, AGEs, or metabolomic profiles would require further research into possible specific molecular species of interest. At present, none of the markers considered here is sufficiently validated and sensitive for routine use in substantiating the effects of sustained variation in dietary glycemic exposures in people without diabetes.

Consuming decaffeinated coffee with milk and sugar added before a high-glycaemic index meal improves postprandial glycaemic and insulinaemic responses in healthy adults

The present study aimed to compare the effects of drinking different types of coffee before a high-glycaemic index (GI) meal on postprandial glucose metabolism and to assess the effects of adding milk and sugar into coffee. In this randomised, crossover, acute feeding study, apparently healthy adults (n 21) consumed the test drink followed by a high-GI meal in each session. Different types of coffee (espresso, instant, boiled and decaffeinated, all with milk and sugar) and plain water were tested in separate sessions, while a subset of the participants (n 10) completed extra sessions using black coffees. Postprandial levels of glucose, insulin, active glucagon-like peptide 1 (GLP-1) and nitrotyrosine between different test drinks were compared using linear mixed models. Results showed that only preloading decaffeinated coffee with milk and sugar led to significantly lower glucose incremental AUC (iAUC; 14 % lower, P = 0·001) than water. Preloading black coffees led to greater postprandial glucose iAUC than preloading coffees with milk and sugar added (12-35 % smaller, P < 0·05 for all coffee types). Active GLP-1 and nitrotyrosine levels were not significantly different between test drinks. To conclude, preloading decaffeinated coffee with milk and sugar led to a blunted postprandial glycaemic response after a subsequent high-GI meal, while adding milk and sugar into coffee could mitigate the impairment effect of black coffee towards postprandial glucose responses. These findings may partly explain the positive effects of coffee consumption on glucose metabolism.

Beneficial effects of lingonberry (Vaccinium vitis-idaea L.) supplementation on metabolic and inflammatory adverse effects induced by high-fat diet in a mouse model of obesity

Obesity is a constantly increasing health problem worldwide. It is associated with a systemic low-grade inflammation, which contributes to the development of metabolic disorders and comorbidities such as type 2 diabetes. Diet has an important role in the prevention of obesity and its adverse health effects; as a part of healthy diet, polyphenol-rich berries, such as lingonberry (Vaccinium vitis-idaea L.) have been proposed to have health-promoting effects. In the present study, we investigated the effects of lingonberry supplementation on high-fat diet induced metabolic and inflammatory changes in a mouse model of obesity. Thirty male C57BL/6N mice were divided into three groups (n = 10/group) to receive low-fat (LF), high-fat (HF) and lingonberry-supplemented high-fat (HF+LGB) diet for six weeks. Low-fat and high-fat diet contained 10% and 46% of energy from fat, respectively. Lingonberry supplementation prevented the high-fat diet induced adverse changes in blood cholesterol and glucose levels and had a moderate effect on the weight and visceral fat gain, which were 26% and 25% lower, respectively, in the lingonberry group than in the high-fat diet control group. Interestingly, lingonberry supplementation also restrained the high-fat diet induced increases in the circulating levels of the proinflammatory adipocytokine leptin (by 36%) and the inflammatory acute phase reactant serum amyloid A (SAA; by 85%). Similar beneficial effects were discovered in the hepatic expression of the inflammatory factors CXCL-14, S100A10 and SAA by lingonberry supplementation. In conclusion, the present results indicate that lingonberry supplementation significantly prevents high-fat diet induced metabolic and inflammatory changes in a murine model of obesity. The results encourage evaluation of lingonberries as a part of healthy diet against obesity and its comorbidities.

Effects of Acute Dietary Polyphenols and Post-Meal Physical Activity on Postprandial Metabolism in Adults with Features of the Metabolic Syndrome

Approximately 22% of U.S. adults and 25% of adults globally have metabolic syndrome (MetS). Key features, such as dysglycemia and dyslipidemia, predict type 2 diabetes, cardiovascular disease, premature disability, and death. Acute supplementation of dietary polyphenols and post-meal physical activity hold promise in improving postprandial dysmetabolism. To our knowledge, no published review has described the effects of either intervention on postprandial glucose, insulin, lipids, and markers of oxidative damage and inflammation in adults with features of MetS. Thus, we conducted this review of controlled clinical trials that provided dietary polyphenols from oils, fruits, teas, and legumes during a dietary challenge, or implemented walking, cycling, and stair climbing and descending after a dietary challenge. Clinical trials were identified using ClinicalTrials.gov, PubMed, and Google Scholar and were published between 2000 and 2019. Dietary polyphenols from extra virgin olive oil, grapes, blackcurrants, strawberries, black tea, and black beans improved postprandial glucose, insulin, and markers of oxidative damage and inflammation, but results were not consistent among clinical trials. Freeze-dried strawberry powder distinctly improved postprandial insulin and markers of oxidative damage and inflammation. Post-meal physical activity attenuated postprandial glucose, but effects on postprandial lipids and markers of oxidative damage and inflammation were inconclusive. Consuming dietary polyphenols with a meal and completing physical activity after a meal may mitigate postprandial dysmetabolism in adults with features of MetS.

Reducing postprandial glucose in dietary intervention studies and the magnitude of the effect on diabetes-related risk factors: a systematic review and meta-analysis

Purpose

Reducing postprandial hyperglycemia has beneficial effects on diabetes-related risk factors, but the magnitude of the reduction needed to achieve such an effect is unknown. The purpose of the study was to quantify the relationship of acute glucose and insulin postprandial responses with longer-term effects on diabetes-related risk factors by performing a systematic review and meta-analysis of dietary intervention studies.

Methods

We systematically searched EMBASE and MEDLINE. Dietary intervention studies among any human population aiming to reduce postprandial glycemia, with actual measures of postprandial glucose (PPG) and/or insulin (PPI) as acute exposures (incremental area under the curve, iAUC) as well as markers of glucose metabolism (fasting glucose, HbA1c) and insulin sensitivity (fasting insulin, HOMA-IR) after at least 4 weeks of diet intervention as outcomes were included. Meta-analyses were performed for the effects on acute exposures and on diabetes-related risk factors. The relationship between changes in acute exposures and changes in risk factor outcomes was estimated by meta-regression analyses.

Results

Out of the 13,004 screened papers, 13 papers with 14 comparisons were included in the quantitative analysis. The dietary interventions acutely reduced mean PPG [mean difference (MD), − 0.27 mmol/l; 95% CI − 0.41 to − 0.14], but not mean PPI (MD − 7.47 pmol/l; 95% CI − 16.79 to 1.86). There were no significant overall effects on fasting glucose and insulin. HbA1c was reduced by − 0.20% (95% CI − 0.35 to − 0.05). Changes in acute PPG were significantly associated with changes in fasting plasma glucose (FPG) [per 10% change in PPG: β = 0.085 (95% CI 0.003, 0.167), k = 14], but not with fasting insulin [β = 1.20 (95% CI − 0.32, 2.71), k = 12]. Changes in acute PPI were not associated with changes in FPG [per 10% change in PPI: β = − 0.017 (95% CI − 0.056, 0.022), k = 11].

Conclusions

Only a limited number of postprandial glucose-lowering dietary intervention studies measured acute postprandial exposures to PPG/PPI during the interventions. In this small heterogeneous set of studies, an association was found between the magnitude of the acute postprandial responses and the change in fasting glucose, but no other outcomes. More studies are needed to quantify the relationship between acute postprandial changes and long-term effects on risk factors.

Electronic supplementary material

The online version of this article (10.1007/s00394-020-02240-1) contains supplementary material, which is available to authorized users.

Antidiabetic effect of Cordia morelosana, chemical and pharmacological studies

ETHNOPHARMACOLOGICAL IMPORTANCE

CORDIA MORELOSANA: Standley (Boraginaceae) is commonly used in folk medicine for the treatment of diarrhoea, kidney inflammation, diabetes, lung pain, bronchitis, asthma, hoarseness, cough and fever.

AIM

Current work was conducted to develop a bio-guided isolation of antidiabetic compounds from ethanolic extract of Cordia morelosana (EECm).

MATERIAL AND METHODS

The phytochemical bio-guided study was conducted by successive chromatographic techniques, and isolated compounds were characterized by 1D and 2D-NMR experiments. The in vivo antihyperglycemic and antidiabetic activities of EECm (100 mg/kg), and methyl rosmarinate (MR, 50 mg/kg) were determined on normoglycemic and diabetic murine models. Additionally, the in vitro activity was conducted to determine α-glucosidase inhibitory effect, and PPARs, GLUT4 and FATP expression on 3T3-L1 cells by RT-PCR. Acute and sub-chronic toxicological studies for EECm were conducted on rats, following the OECD guidelines (No. 420 and 407).

RESULTS

EECm promotes significant α-glucosidase inhibition (55.6%) at 1 mg/kg respect to the control. Also, EECm (100 mg/kg) showed significant antihyperglycemic effect on oral glucose tolerance test (OGTT), and in non-insulin dependent type 2 diabetes (NIDD) model, had antidiabetic activity (p < 0.001) compared to controls. The bio-guided isolation allowed to obtain four known compounds described as rosmarinic acid (RA), methyl rosmarinate (MR), nicotiflorine and 1-O-methyl-scyllo-inositol. On the other hand, MR showed significant antidiabetic and anthiyperglycemic activities (p < 0.05), and overexpression of PPARγ, PPARα, GLUT-4 and FATP than control. Docking studies were conducted with PPARγ and PPARα, showing interesting binding mode profile on those targets. Finally, EECm displayed a LD₅₀ > 2000 mg/kg and sub-chronic toxicological study reveals no toxic signs in animals tested compared to control.

CONCLUSION

EECm showed significant antihyperglycemic and antidiabetic actions being RA and MR the main antidiabetic metabolites.

High or low glycemic index (GI) meals at dinner results in greater postprandial glycemia compared with breakfast: a randomized controlled trial

INTRODUCTION

While circadian control of glucose metabolism is well known, how glycemic index (GI) of carbohydrate-rich meals interacts with time of consumption (breakfast or dinner) to influence postprandial (PP) glucose homeostasis is less well established. The objective of the study was to assess markers of PP glucose homeostasis following high or low GI test meals (TM) consumed either at breakfast or at dinner and following consumption of the subsequent standardized meals (SSM).

RESEARCH DESIGN AND METHODS

Randomized crossover trial in 34 healthy, Chinese, elderly volunteers (mean±SEM age, 56.8±0.83 years), who completed 4 separate study sessions per-protocol, consisting of a high-GI breakfast, low-GI breakfast, high-GI dinner and low-GI dinner TM, followed by a SSM at the subsequent eating occasion. Blood samples were taken for 3 hours after each TM and SSM for glucose, insulin, glucagon, free fatty acids (FFA) and triglycerides (TG) measurements.

RESULTS

Consuming TM at dinner produced greater PP glycemia than breakfast both after TM and SSM (both p<0.0001), irrespective of GI. High-GI TM also produced greater PP glycemia than low-GI TM, both after TM and SSM (both p<0.01), irrespective of time of consumption. No interaction between GI and time were found on PP glycemia, indicating parallel, but independent effects. Combined total areas under the curve of TM+SSM for PP glucose (p<0.0001), PP TG (p<0.0001) and PP FFA (p<0.0001) were all greater when TM taken during dinner compared with breakfast.

CONCLUSIONS

Carbohydrate-rich meals consumed at dinner leads to significantly worse PP glucose homeostasis than when consumed at breakfast, on top of the independent GI effect of the meal. This may have implications to future type 2 diabetes risk. Moreover, future studies investigating GI/glycemic load (GL) and disease risk associations should factor in timing of GL consumption as an additional variable.

TRIAL REGISTRATION NUMBER

NCT02927600.

Flash Glucose Monitoring Can Accurately Reflect Postprandial Glucose Changes in Healthy Adults in Nutrition Studies

OBJECTIVE

This study investigated the accuracy of a flash glucose monitoring system (FGMS) in a postprandial setting.

METHODS

Ten fasted adults without diabetes wore the FGMS sensors then consumed a standard breakfast. Their glucose levels were subsequently recorded for 2 hours, both by the FGMS and by measuring capillary glucose levels using the glucose oxidase method. The accuracy of the FGMS data was assessed using the accuracy limits stated in ISO 15197:2013.

RESULTS

FGMS measurements were mostly lower than glucose oxidase measurements (mean absolute relative difference ± SD: 25.4 ± 17.0%, p < 0.001). However, the maximum difference from baseline captured by the two methods was not significantly different (mean ± SD, glucose oxidase: 58.5 ± 18.9 mg/dl; FGMS, 54.4 ± 28.9 mg/dl, p = 0.366).

CONCLUSIONS

FGMS could track the incremental glycaemic excursions after meals in adults without diabetes, yet further studies with greater sample sizes are needed to confirm this finding.

Lemon juice, but not tea, reduces the glycemic response to bread in healthy volunteers: a randomized crossover trial

PURPOSE

The inhibition of enzymes that hydrolyze starch during digestion could constitute an opportunity to slow down the release, and ultimately the uptake, of starch-derived glucose. Simple dietary approaches consisting in pairing starch-rich foods with beverages that have the capacity to inhibit such enzymes could be an effective and easily implementable strategy. The objective of this work was to test the impact of black tea and lemon juice on the glycemic response to bread and subsequent energy intake in healthy adults.

METHODS

A randomized crossover study was conducted with equal portions of bread (100 g) and 250 ml of water, black tea or lemon juice. Capillary blood glucose concentrations were monitored during 180 min using the finger-prick method. Ad libitum energy intake was assessed 3 h later.

RESULTS

Tea had no effect on the glycemic response. Lemon juice significantly lowered the mean blood glucose concentration peak by 30% (p < 0.01) and delayed it more than 35 min (78 vs. 41 min with water, p < 0.0001). None of the tested beverages had an effect on ad libitum energy intake.

CONCLUSION

These results are in agreement with previous in vitro studies showing that lowering the pH of a meal can slow down starch digestion through premature inhibition of salivary α-amylase. Furthermore, the effect of lemon juice was similar to what has been repeatedly observed with vinegar and other acidic foods. Including acidic beverages or foods in starchy meals thus appears to be a simple and effective strategy to reduce their glycemic impact.

Postprandial glucose response moderation by cardiorespiratory fitness following short exercise bouts

BACKGROUND

Previous reports indicate that postprandial glucose (PPG) responses to exercise may depend on cardiorespiratory fitness (CRF), such that less fit individuals have greater reductions in PPG with exercise. Our aim was to investigate moderating effects of CRF on PPG response following exercise of progressively shorter durations and sedentary rest.

METHODS

Thirty-four participants (14 female) completed a 75-g oral glucose tolerance test (OGTT) at seated rest. On three subsequent visits, participants completed additional OGTT with either 1, 3, or 10 minutes of stair-climbing. Fingerstick blood glucose measurements were taken every 15 minutes for 1 hour. CRF was determined using a treadmill ramp test.

RESULTS

There was a main effect of condition F(3, 93)=13.07, P<0.001, ηp2=0.30. Stair-climbing reduced PPG iAUC compared to control by -3±27% (P=0.546), -11±29% (P=0.091), and -28±22% (P<0.000) for the 1, 3 and 10 min bouts, respectively. There was no trial by CRF interaction for glucose iAUC F(2.4, 73.8)=0.69, P=0.532, ηp2=0.02. Linear mixed model regression analysis revealed that CRF was not significantly associated with glucose iAUC, b=-14 (-45, 16), P=0.339.

CONCLUSIONS

Contrary to previous reports CRF did not moderate PPG responses for either sedentary or exercise conditions in healthy men and women. Short, single-bout stair stepping exercise at a self-selected pace is equally efficient for all fitness levels.

Obesity and adiposity: the culprit of dietary protein efficacy

Obesity and increased body adiposity have been alarmingly increasing over the past decades and have been linked to a rise in food intake. Many dietary restrictive approaches aiming at reducing weight have resulted in contradictory results. Additionally, some policies to reduce sugar or fat intake were not able to decrease the surge of obesity. This suggests that food intake is controlled by a physiological mechanism and that any behavioural change only leads to a short-term success. Several hypotheses have been postulated, and many of them have been rejected due to some limitations and exceptions. The present review aims at presenting a new theory behind the regulation of energy intake, therefore providing an eye-opening field for energy balance and a potential strategy for obesity management.

Standardized Emblica officinalis fruit extract inhibited the activities of α-amylase, α-glucosidase, and dipeptidyl peptidase-4 and displayed antioxidant potential

BACKGROUND

Emblica officinalis, known as amla in Ayurveda, has been used as a folk medicine to treat numerous pathological conditions, including diabetes. However, the novel extract of E. officinalis fruit extract (amla fruit extract, AFE, Saberry®) containing 100 g kg^-1 β-glucogallin along with hydrolyzable tannins has not yet been extensively studied for its antidiabetic potential.

OBJECTIVE

The aim of this study was to investigate the antidiabetic and antioxidant activities of AFE and its stability during gastric stress as well as its thermostability.

METHODS

The effect of AFE on the inhibition of pancreatic α-amylase and salivary α-amylase enzymes was studied using starch and yeast α-glucosidase enzyme using 4-nitrophenyl α-d-glucopyranoside as substrate. Further, 2,2-diphenyl-1-picrylhydrazyl radical scavenging and reactive oxygen species inhibition assay was performed against AFE.

RESULTS

AFE potently inhibited the activities of α-amylase and α-glucosidase in a concentration-dependent manner with half maximal inhibitory concentration (IC₅₀ ) values of 135.70 μg mL^-1 and 106.70 μg mL^-1 respectively. Furthermore, it also showed inhibition of α-glucosidase (IC₅₀ 562.9 μg mL^-1 ) and dipeptidyl peptidase-4 (DPP-4; IC₅₀ 3770 μg mL^-1 ) enzyme activities. AFE is a potent antioxidant showing a free radical scavenging activity (IC₅₀ 2.37 μg mL^-1 ) and protecting against cellular reactive oxygen species (IC₅₀ 1.77 μg mL^-1 ), and the effects elicited could be attributed to its phytoconstituents.

CONCLUSION

AFE showed significant gastric acid resistance and was also found to be thermostable against wet heat. Excellent α-amylase, α-glucosidase, and DPP-4 inhibitory activities of AFE, as well as antioxidant activities, strongly recommend its use for the management of type 2 diabetes mellitus. © 2019 The Authors. Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

The effects of low-carbohydrate diets on cardiovascular risk factors: A meta-analysis

Background

Low-carbohydrate diets are associated with cardiovascular risk factors; however, the results of different studies are inconsistent.

Purpose

The aim of this meta-analysis was to assess the relationship between low-carbohydrate diets and cardiovascular risk factors.

Method

Four electronic databases (PubMed, Embase, Medline, and the Cochrane Library) were searched from their inception to November 2018. We collected data from 12 randomized trials on low-carbohydrate diets including total cholesterol, high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C), triglycerides, and blood pressure levels, as well as weight as the endpoints. The average difference (MD) was used as the index to measure the effect of a low-carbohydrate diet on cardiovascular risk factors with a fixed-effects model or random-effects model. The analysis was further stratified by factors that might affect the results of the intervention.

Results

From 1292 studies identified in the initial search results, 12 randomized studies were included in the final analysis, which showed that a low-carbohydrate diet was associated with a decrease in triglyceride levels of -0.15mmol/l (95% confidence interval -0.23 to -0.07). Low-carbohydrate diet interventions lasting less than 6 months were associated with a decrease of -0.23mmol/l (95% confidence interval -0.32 to -0.15), while those lasting 12–23 months were associated with a decrease of -0.17mmol/l (95% confidence interval -0.32 to -0.01). The change in the body weight in the observation groups was -1.58kg (95% confidence interval -1.58 to -0.75); with for less than 6 months of intervention,this change was -1.14 kg (95% confidence interval -1.65 to -0.63),and with for 6–11 months of intervention, this change was -1.73kg (95% confidence interval -2.7 to -0.76). The change in the systolic blood pressure of the observation group was -1.41mmHg (95% confidence interval—2.26 to -0.56); the change in diastolic blood pressure was -1.71mmHg (95% confidence interval—2.36 to -1.06); the change in plasma HDL-C levels was 0.1mmHg (95% confidence interval 0.08 to 0.12); and the change in serum total cholesterol was 0.13mmol/l (95% confidence interval 0.08 to 0.19). The plasma LDL-C level increased by 0.11mmol/l (95% confidence interval 0.02 to 0.19), and the fasting blood glucose level changed 0.03mmol/l (95% confidence interval -0.05 to 0.12),which was not significant.

Conclusions

This meta-analysis confirms that low-carbohydrate diets have a beneficial effect on cardiovascular risk factors but that the long-term effects on cardiovascular risk factors require further research.

The healthy Nordic diet for blood glucose control: a systematic review and meta-analysis of randomized controlled clinical trials

AIMS

Investigations on the possible effect of the Nordic diet (ND) on the glycemic control and the risk of diabetes have led to inconsistent results. The present study tried to determine the effect of the ND on the markers of blood glucose control using a systematic review and meta-analysis of randomized controlled clinical trials (RCTs).

METHODS

Predefined keywords were used to search PubMed, ISI Web of Science, Scopus and Google Scholar up to April 2019. The random effects model was used to compute the overall estimates.

RESULTS

In total, six RCTs with 618 participants (6-26 weeks of follow-up period) were included in the present study. The meta-analysis revealed that the ND might not have a considerable effect on fasting blood glucose levels [weighted mean difference (WMD) = -0.05 mmol/l, 95% CI - 0.13, 0.01, P = 0.112]. In contrast, the analyses showed that the ND significantly reduces serum insulin concentrations (WMD = -1.12 mU/l, 95% CI - 1.84, - 0.39, P = 0.002) and the homeostasis model assessment for insulin resistance (HOMA-IR) (WMD = - 0.34, 95% CI - 0.53, - 0.14, P = 0.001) compared to control diets. The effect on serum insulin levels was sensitive to one of the included studies. This dietary pattern did not significantly affect 2-h post-prandial blood glucose and Matsuda index.

CONCLUSIONS

Adherence to the ND might improve serum insulin and HOMA-IR levels; however, this effect was not confirmed for other markers of blood glucose control. Future well-designed and long-term clinical trials are highly recommended.

Glycated Haemoglobin Is Associated With Poorer Cognitive Performance in Patients With Recent-Onset Psychosis

BACKGROUND

Glucose abnormalities and cognitive alterations are present before the onset of schizophrenia. We aimed to study whether glucose metabolism parameters are associated with cognitive functioning in recent-onset psychosis (ROP) patients while adjusting for hypothalamic-pituitary adrenal (HPA) axis measures.

METHODS

Sixty ROP outpatients and 50 healthy subjects (HS) were studied. Cognitive function was assessed with the MATRICS Consensus Cognitive Battery. Glycated haemoglobin (HbA1_c), glucose, insulin, and C-peptide levels were determined in plasma. The HOMA-insulin resistance index was calculated. Salivary samples were obtained at home on another day to assess the cortisol awakening response and cortisol levels during the day. Univariate analyses were conducted to explore the association between glucose metabolism parameters and cognitive tasks. For those parameters that were more clearly associated with the cognitive outcome, multiple linear regression analyses were conducted to adjust for covariates. Each cognitive task was considered the dependent variable. Covariates were age, sex, education level, diagnosis, antipsychotic and benzodiazepine treatment, body mass index (BMI), smoking, and HPA axis measures. Potential interactions between diagnosis and glucose parameters were tested.

RESULTS

There were no significant differences in HPA axis measures or glucose parameters, with the exception of C-peptide (that was higher in ROP patients), between groups. ROP patients had a lower performance than HS in all cognitive tasks (p < 0.01 for all tasks). Of all glucose metabolism parameters, HbA1c levels were more clearly associated with cognitive impairment in cognitive tasks dealing with executive functions and visual memory in both ROP patients and HS. Multivariate analyses found a significant negative association between HbA1c and cognitive functioning in five cognitive tasks dealing with executive functions, visual memory and attention/vigilance (a ROP diagnosis by HbA1_c negative interaction was found in this latter cognitive domain, suggesting that HBA1_c levels are associated with impaired attention only in ROP patients).

CONCLUSIONS

Our study found that HbA1_c was negatively associated with cognitive functioning in both ROP patients and HS in tasks dealing with executive functions and visual memory. In ROP patients, HbA1_c was also associated with impaired attention. These results were independent of BMI and measures of HPA axis activity.

A herbal premix containing Macrotyloma uniflorum, ginger, and whey curtails obesity in rats fed a high-fat diet by a novel mechanism

The present study designed and evaluated a polyherbal premix comprising Macrotyloma uniflorum, whey protein, Zingiber officinale, and Mentha piperita. Animals were fed a high-fat diet (HFD) for 30 days and were daily administered the premix (1.5 g/kg) in milk (PM) and water (PW), aerobic exercise (AE), premix in milk and water along with AE (PMAE and PWAE), ferulic acid (100 mg/kg), and the reference drug fluoxetine (6 mg/kg). All treatments showed significant reduction in food intake, weight gain, abdominal circumference, and body mass index compared with their initial values. All treatments generated a faster peak of the satiety marker cholecystokinin compared with the HFD group and control groups; PMAE and PWAE exhibited sustained satiety. The HFD-elevated blood glucose levels were significantly attenuated on the 30th day by all treatments when compared with their 15th day and basal values; PMAE exhibited the best results. All treatments significantly attenuated the HFD-elevated serum insulin, homeostasis model assessment of insulin resistance, C-reactive protein, triglycerides, total cholesterol, very-low-density lipoprotein, and low-density lipoprotein levels and significantly restored the HFD-depleted high-density lipoprotein and adiponectin levels. HFD-elevated thiobarbituric acid reactive substances values were attenuated successfully and the HFD-depleted reduced glutathione, superoxide dismutase, and catalase levels were significantly restored by all treatments. The histological findings corroborated the biochemical results. Novelty The polyherbal premix brought about appetite regulation and induction of satiety to control obesity in HFD-fed rats through homeostasis of energy metabolism. The premix along with exercise is a complete way to combat obesity.

Hypoglycemic Potential of Supplementation with a Vegetable and Legume Juice Formula in Type 2 Diabetic Patients

BACKGROUND AND OBJECTIVE

Type 2 diabetes affects a large number of people all over the world; hence, it is worthy to supplement those patients with a food formula containing biologically active ingredients that can help to control the disease and its complications. The present study was designed to prepare a plant formula in the form of a juice taken during treatment to synergies and reduce the drug dose used and minimize disease complications.

MATERIALS AND METHODS

The formula is formed of spinach, broccoli, celery, green beans and chickpea. The total fat, fatty acids, polyphenol content and the antioxidant power of the formula were determined. The blood sugar tolerance curves of the volunteers were followed after breakfast alone, breakfast and treatment dose, also when this formula was given before breakfast.

RESULTS

The vegetable and legume juice could reduce postprandial glucose level when given before the breakfast and the effect was more or less similar to the effect of the treatment drug. The juice proved to contain some polyphenols and possess an antioxidant character. Analysis proved that it is rich in polyunsaturated fatty acids.

CONCLUSION

It is recommended to use this juice for diabetic patients to reduce hyperglycemia and synergize the effect of the used drug. It can thus avoid health problems that occur to those patients when using drugs for long time and in massive amounts.

Oral intake of slowly digestible α-glucan, isomaltodextrin, stimulates glucagon-like peptide-1 secretion in the small intestine of rats

To investigate whether oral intake of highly branched α-glucan isomaltodextrin (IMD) could stimulate ileal glucagon-like peptide-1 (GLP-1) secretion, we examined (1) the digestibility of IMD, (2) the digestion and absorption rates of IMD, in rat small intestine and (3) portal GLP-1 concentration in rats given IMD. In Expt 1, ileorectostomised rats were given a 3 % IMD diet for 10 d. Separately, a 16-h in vitro digestion of IMD, using porcine pancreatic α-amylase and brush-border membrane vesicles from rat small intestine, was conducted. In Expt 2, upon 24-h fasting, rats were given any of glucose, IMD and high-amylose maize starch (HAMS) (1 g/kg of body weight). In Expt 3, caecectomised rats were given 0·2 % neomycin sulphate and a 5 % IMD diet for 10 d. The in vivo and in vitro digestibility of IMD was 70-80 %. The fraction of IMD digested in vitro for the first 120 min was 67 % of that in maize starch. The AUC for 0-120 min of plasma glucose concentration was significantly lower in HAMS group and tended to be lower in IMD group than in the glucose group. Finally, we also observed that, when compared with control rats, glucose of IMD significantly stimulated and improved the concentration of portal active GLP-1 in antibiotic-administered, caecectomised rats. We concluded that IMD was slowly digested and the resulting glucose stimulated GLP-1 secretion in rat small intestine. Oral delivery of slowly released IMD glucose to the small intestine probably exerts important, yet unknown, physiological effects on the recipient.

Moderate Postmeal Walking Has No Beneficial Effects Over Resting on Postprandial Lipemia, Glycemia, Insulinemia, and Selected Oxidative and Inflammatory Parameters in Older Adults with a Cardiovascular Disease Risk Phenotype: A Randomized Crossover Trial

BACKGROUND

Research suggests that postprandial events, as risk factors for cardiovascular diseases (CVDs), are influenced by meal composition and exercise.

OBJECTIVES

We investigated the effect of walking versus rest on postprandial metabolic, inflammatory, and oxidative events following the consumption of test meals reflecting 2 different dietary patterns in older adults with an increased CVD risk.

METHODS

A randomized crossover trial was conducted in 26 men and women (aged 70 ± 5 y; BMI 30.3 ± 2.3 kg/m2). Each adult participated in 4 treatments combining 1 of 2 iso-energetic (4300 kJ) meals [Western diet high-fat meal (WD): total fat, 59.4 g; saturated fatty acids, 32.0 g, dietary fiber, 4.2 g; or Mediterranean-type diet meal (MD): total fat, 40.1 g; saturated fatty acids, 5.1 g; dietary fiber, 14.5 g] with 30 min walking (4.6 ± 0.1 km/h) or rest. Primary (serum triglycerides) and secondary [serum nonesterified fatty acids (NEFAs); parameters of glucose metabolism, inflammation, endothelial activation, oxidation; blood pressure/heart rate] outcomes were measured at fasting and 1.5, 3.0, and 4.5 h postprandially. Data were analyzed by linear mixed models.

RESULTS

Triglycerides were higher after the WD than after the MD [AUC in mmol/L × min: Western diet high-fat meal plus postprandial walking (WD-W), 218 ± 15.2; Western diet high-fat meal plus postprandial resting (WD-R), 207 ± 12.6; Mediterranean-type diet meal plus postprandial walking (MD-W), 139 ± 9.83; Mediterranean-type diet meal plus postprandial resting (MD-R), 149 ± 8.15; P  < 0.001]. No meal or activity effect was observed for NEFAs based on AUC data (WD-W, -43.5 ± 7.08; WD-R, -49.2 ± 6.94; MD-W, -48.0 ± 11.6; MD-R, -67.6 ± 7.58). Plasma glucose was higher after the MD than after the WD (WD-W, 222 ± 34.9; WD-R, 177 ± 32.8; MD-W, 314 ± 44.4; MD-R, 275 ± 57.8; P  < 0.001), as was serum insulin (AUC in nmol/L × min: WD-W, 82.0 ± 10.3; WD-R, 88.6 ± 12.8; MD-W, 129 ± 14.7; MD-R, 138 ± 20.5; P < 0.001). Plasma IL-6 was higher after walking than after resting (AUC in pg/mL × min: WD-W, 72.0 ± 34.0; WD-R, 14.3 ± 38.8; MD-W, 70.8 ± 39.4; MD-R, 5.60 ± 26.0; P < 0.05). Plasma vitamin C was higher after the MD than after the WD (P < 0.001) and after walking than after resting (P < 0.05; AUC in mg/L × min: WD-W, -305 ± 59.6; WD-R, -396 ± 84.0; MD-W, 113 ± 56.4; MD-R, -44.5 ± 48.1). We observed no meal or activity effects on parameters of oxidation and endothelial adhesion molecules. Our data revealed no significant meal × activity effects on all outcomes.

CONCLUSIONS

In older adults with an increased CVD risk, the MD was associated with superior effects on several postprandial parameters (e.g., triglycerides), in comparison to the WD. Data revealed no relevant differences regarding the effects of postmeal walking and resting. None of the 4 treatments can be rated as superior regarding their acute effects on the shown postprandial metabolic, oxidative, and inflammatory parameters. The trial was registered at German Clinical Trials Register (DRKS; http://www.germanctr.de and http://www.drks.de) under identifier DRKS00012409.

The Rate of Glucose Appearance Is Related to Postprandial Glucose and Insulin Responses in Adults: A Systematic Review and Meta-analysis of Stable Isotope Studies

BACKGROUND

It is often assumed that lower postprandial glucose (PPG) and insulin (PPI) responses are induced by slower glucose influx from the gut (e.g., by delayed carbohydrate digestion). However, changes in the rate of appearance of glucose in the peripheral circulation [rate of appearance of exogenous glucose (RaE)] may be accompanied by changes in endogenous glucose production (EGP) and the rate of disappearance of total glucose into tissues (RdT). The quantitative relationships between reductions in RaE and PPG/PPI levels are unclear.

OBJECTIVES

The objective was to perform a meta-analysis to quantify the effect of changes in RaE on changes in PPG and PPI levels (primary) and EGP and RdT (secondary).

METHODS

We systematically searched the Scopus, Medline, and Cochrane library databases through 10 January 2019 for randomized, controlled, carbohydrate-rich interventions that aimed to reduce RaE in humans, measured using dual or triple stable isotope methods. The 2-h net incremental AUCs for all variables were extracted or calculated. Relationships between RaE and outcomes were quantified by weighted regression analyses.

RESULTS

There were 12 articles, including 17 comparisons, that satisfied the inclusion criteria. The subjects were mainly men (60%), with age and BMI ranges of 18-40 y and 20.0-27.5 kg/m2, respectively. A 10% reduction in RaE was associated with reductions in PPG levels, PPI levels, and the RdT of 7% (95% CI: 2%, 12%; P = 0.010), 8% (95% CI: 2%, 13%; P = 0.012), and 11% (95% CI: 4%, 17%; P = 0.005), respectively, but was not significantly associated with a change in EGP (13%; 95% CI: -7%, 33%; P = 0.176). All fluxes together explained 70% and 26% of the variances in PPG and PPI levels, respectively.

CONCLUSIONS

In adults, reducing glucose RaE by diet is associated with significant reductions in PPG levels, PPI levels, and the rate of glucose disposal. This trial was registered in the PROSPERO database with identifier CRD42018084824.

Enzyme-treated orange pomace alters acute glycemic response to orange juice

The goal of the present study was to determine the impact of the addition of enzyme-treated orange pomace to orange juice on postprandial glycemic response. Ten healthy subjects (aged 27.9 ± 7.7 years, body mass index 22.1 ± 1.1 kg m⁻²) participated in a randomized, 2-arm, cross-over clinical trial to test the glycemic response to 100% orange juice (OJ) or 100% orange juice with 5 g of enzyme-treated orange pomace fiber (OPF). Blood samples were collected and glucose and insulin concentrations were measured at fasting (0 min) and every 15 min for 2 h after consuming the study juice products. Analysis of the 2 h incremental area under the curve (iAUC_0–2h) indicated a significant reduction in blood glucose after ingesting the OPF juice compared to the OJ, p = 0.02. Peak glucose concentrations were also lowered after the OPF juice compared to the OJ, p < 0.05. No significant difference was observed in insulin responses between treatments, p > 0.05. Overall, this study demonstrated that adding 5 g of fiber from orange pomace into a serving of OJ attenuated the postprandial glucose response.

Immediate post-breakfast physical activity improves interstitial postprandial glycemia: a comparison of different activity-meal timings

The optimal timing between meal ingestion and simple physical activity for improving blood glucose control is unknown. This study compared the effects of physical activity on postprandial interstitial glucose responses when the activity was conducted either immediately before, immediately after, or 30 min after breakfast. Forty-eight adults were randomized to three separate physical activity interventions: standing still (for 30 min), walking (for 30 min), and bodyweight exercises (3 sets of 10 squats, 10 push-ups, 10 lunges, 10 sit-ups). In each intervention, 16 participants completed four trials (A to D) during which a 500 kcal mixed nutrient liquid breakfast meal was consumed. Interstitial glucose responses were recorded using continuous glucose monitoring for 2 h after the meal. The activity was completed either after the glucose monitoring period (trial A; control) or immediately before (trial B), immediately after (trial C), or 30 min after (trial D) the breakfast. Mean, coefficient of variance (CV), and area under the curve (AUC) for glucose were calculated and compared between the four trials. Walking and bodyweight exercises immediately after the meal improved mean, CV, and AUC glucose (P ≤ 0.05 vs. control), while standing immediately after the meal only improved AUC glucose (P ≤ 0.05 vs. control) and nearly improved mean glucose (P = 0.06). Mean, CV, and AUC glucose were not affected by standing, walking, or bodyweight exercise conducted immediately before, or 30 min after the meal (all P > 0.05 vs. control). Energy intake (diet records) and energy expenditure (Actigraph) were consistent throughout the studies and did not influence the findings. Low- to moderate-intensity activity should be implemented soon after eating to improve glucose control following breakfast. The type of activity appears less important than the timing. These findings will help optimize exercise-meal timing in general health guidelines. ClinicalTrials.gov Identifier: NCT03730727

High-throughput method for preliminary screening of high dietary fiber rice

Dietary fiber has several benefits for humans, and the development of healthier rice with an improved dietary fiber composition has attracted increasing amounts of attention. Based on the method of AOAC 2002.02, we developed a simplified method to screen polished rice containing high total dietary fiber (TDF). Mutant cw with a high TDF content could be distinguished easily from R7954 (indica) and Nipponbare (japonica) by the digestion-resistant phenotype, which is characterized as an almost intact grain after hydrolysis by pepsin, pancreatic α-amylase and amyloglucosidase. The individuals identified from the F₂ population showed digestion resistance all had TDF content higher than 5%, while those without a digestion-resistant phenotype had TDF content lower than 5%. The phenotype of digestion resistance could be a valuable index for identifying rice with higher TDF content, and the identification of this phenotype provides a simplified, economical and high throughput method for high TDF rice breeding.

Effect of liquid sourdough technology on the pre-biotic, texture, and sensory properties of a crispy flatbread

The present study compared liquid sourdough technology with baker's yeast leavening when applied to the production of a semolina-based crispy flatbread. Following in vitro starch digestion, the results revealed the sourdough leavened flatbread to contain a lower percentage of rapidly digestible starch (16%), higher amounts of slowly digestible starch (27%) and inaccessible digestible starch (4.1%) compared with the baker's yeast leavened flatbread (20, 20, and 2.4%, respectively), making the former nutritionally healthier. The sourdough leavened bread was crispier, stiffer and more solid, as shown by texture analyses, although Raman spectroscopy revealed no differences in the crystallinity status of starch. The descriptive analyses show that the use of sourdough enhances the positive sensory traits, as rated by the consumer panel scores (6.08 vs. 5.56). In summary, the results indicate that the implementation of sourdough technology in the production of flat crispy breads could confer economic advantages to this product.

Postprandial Metabolic Effects of Fiber Mixes Revealed by in vivo Stable Isotope Labeling in Humans

Food supplementation with a fiber mix of guar gum and chickpea flour represents a promising approach to reduce the risk of type 2 diabetes mellitus (T2DM) by attenuating postprandial glycemia. To investigate the effects on postprandial metabolic fluxes of glucose-derived metabolites in response to this fiber mix, a randomized, cross-over study was designed. Twelve healthy, male subjects consumed three different flatbreads either supplemented with 2% guar gum or 4% guar gum and 15% chickpea flour or without supplementation (control). The flatbreads were enriched with ~2% of ¹³C-labeled wheat flour. Blood was collected at 16 intervals over a period of 360 min after bread intake and plasma samples were analyzed by GC-MS based metabolite profiling combined with stable isotope-assisted metabolomics. Although metabolite levels of the downstream metabolites of glucose, specifically lactate and alanine, were not altered in response to the fiber mix, supplementation of 4% guar gum was shown to significantly delay and reduce the exogenous formation of these metabolites. Metabolic modeling and computation of appearance rates revealed that the effects induced by the fiber mix were strongest for glucose and attenuated downstream of glucose. Further investigations to explore the potential of fiber mix supplementation to counteract the development of metabolic diseases are warranted.

The rationale and design of the personal diet study, a randomized clinical trial evaluating a personalized approach to weight loss in individuals with pre-diabetes and early-stage type 2 diabetes

Weight loss reduces the risk of type 2 diabetes mellitus (T2D) in overweight and obese individuals. Although the physiological response to food varies among individuals, standard dietary interventions use a "one-size-fits-all" approach. The Personal Diet Study aims to evaluate two dietary interventions targeting weight loss in people with prediabetes and T2D: (1) a low-fat diet, and (2) a personalized diet using a machine-learning algorithm that predicts glycemic response to meals. Changes in body weight, body composition, and resting energy expenditure will be compared over a 6-month intervention period and a subsequent 6-month observation period intended to assess maintenance effects. The behavioral intervention is delivered via mobile health technology using the Social Cognitive Theory. Here, we describe the design, interventions, and methods used.

Glycemic effects following the consumption of mixed soy protein isolate and alginate beverages in healthy adults

This study examined whether the consumption of beverages containing mixed soy protein isolate (SPI) and fiber, alginate (ALG), would affect postprandial glucose and insulin responses or appetite in healthy adults. Following an overnight fast, twelve healthy subjects were asked to consume six standardized breakfast beverages in a randomized order: a 122 kcal sugar beverage (CONT), a 122 kcal sugar beverage with ALG, a 172 kcal sugar beverage with SPI at pH 7 (SPI-7) or 6 (SPI-6), and a 172 kcal sugar beverage with mixed SPI and alginate at pH 7 (SPI + ALG-7) or 6 (SPI + ALG-6). Subjects consumed one of the beverages at time 0. Blood samples were drawn at -15, 0, 15, 30, 45, 60, 90 and 120 min and questionnaires were completed immediately following the blood drawing at each time point. The results showed that, compared to CONT, the consumption of SPI-7, SPI-6, SPI + ALG-7 and SPI + ALG-6 significantly lowered (P < 0.05) the peak plasma glucose concentration (33.4%, 36.3%, 53.2%, and 58.5%, respectively), 120 min incremental area under the curve (AUC), and peak insulin concentration. SPI + ALG-6 and SPI + ALG-7 exhibited a significant reduction in the peak glucose concentration compared to SPI without alginate (P < 0.05). No significant effect on appetite was found in any conditions. Electrostatic interactions between the protein and alginate during digestion and formation of intragastric gel could play an important role in influencing the postprandial glucose response. This study indicates that the consumption of mixed SPI and ALG beverages was the most effective in attenuating the postprandial glycemic excursion in healthy adult subjects.

Association between selected trace elements and body mass index and waist circumference: A cross sectional study

BACKGROUND

The prevalence of obesity has increased worldwide. Abnormal plasma level of some trace elements may be associated with obesity. The present study was designed to compare the plasma level of zinc, phosphate, calcium and magnesium with the degree of body mass index and waist circumference.

MATERIAL AND METHODS

In this cross sectional study 149 persons (20-60 years old) from March 2014 till April 2017 were included. Definition of central obesity was waist circumference (WC)≥ 102 cm and ≥88 cm in men and women, respectively. Also BMI categorized to: normal weight: 18.50-24.99, overweight: 25.00-29.99 and obese: ≥30 kg/m2 respectively. Mg, Ca, P and Zinc in plasma was checked after12 h fasting in each persons. Comparison between the level of Mg, P, Ca and Zinc by three categories of BMI or waist circumference performed. The data were analyzed by independent T-test and one-way ANOVA. Scheffe method was used to determine post-hoc pair-wise comparisons. The relationship between BMI and concentration of elements was detected by linear correlation and Cubic model. A p ≤ 0.05 were considered statistically significant. Statistical analyses were executed by SPSS version 20.

RESULTS

In this study, 32.2% male and remainder female, mean age of 42.26 ± 13.03 were participated. 40.9% were normal and 59.1% obese base on waist circumference. Also 24.8% normal,44.3% overweight and remainder was obese according to BMI. Obese subjects base on waist circumference had significantly lower serum Zinc(pvalue:0.002), Ca (pvalue:0.0001)and Mg(pvalue:0.042) concentration. Whereas, P concentration was significantly higher in obese cases in comparison with normal subjects(pvalue:0.012). Also normal cases had significantly higher serum Zinc (pvalue: 0.0001), Ca (pvalue:0.0001), and Mg(pvalue:0.006) concentration compared to overweight and obese subjects according to BMI categorizes.

CONCLUSION

Inverse correlation present between plasma zinc, calcium and magnesium level and BMI and waist circumference, but positive correlation seen between P level and waist circumference. Further studies are needed to evaluate the effect of dietary or supplemental interventions on obesity and central obesity.

Reducing Glycemic Indicators with Moderate Intensity Stepping of Varied, Short Durations in People with Pre-Diabetes

Investigate the effects of short duration stair climbing/descending at a self-selected pace on post-prandial glucose responses in adults. Thirty participants (10 female) completed 4 oral glucose tolerance tests on separate days. Following glucose consumption, participants underwent seated rest (control) or walked up/down 21 stairs at a self-selected comfortable pace for 10, 3, and 1min in randomized order. Blood glucose was measured by capillary sampling from finger sticks every 15min until values for all trials converged. Area under the curve (AUC) was calculated by trapezoidal rule. In addition, cardiometabolic measurements were taken during stair exercise with a mobile metabolic cart. Results are presented as mean (SD) unless stated otherwise. All stair-climbing trials reduced peak (30min) postprandial blood glucose levels compared to the control [(1 min = 12(31), p = 0.026; 3 min = -15(25), p = 0.003; 10 min = 35(32) mg/dL, p < 0.001]. At 45min, there were significant reductions only for the 3 and 10 min trials [13(29) and 23(31) mg/dL, p = 0.023 and < 0.001 respectively], but not the 1 min trial [6(33) mg/dL, p = 0.317]. There were significant differences in AUC compared to the control only for the 3 and 10min trials [502 (1141) and 866 (1123) mg/dL·min^-1, p = 0.023 and < 0.000] but not for the 1min trial [353 (1265) mg/dL·min^-1, p = 0.110]. Median (interquartile range) RPEs reported for the 1, 3, and 10min trials were 1.0 (1.5), 2.0(2), and 3.0 (2.0) respectively, while VO₂ was n/a, 54(12), and 59(13)% of peak, respectively. Total metabolic cost was 1.4 (0.5), 4.0 (1.0), and 11.9 (2.1) L O₂, respectively. A single 1min bout of low-moderate intensity stair stepping can significantly lower peak glucose concentration, with longer bouts being more effective.

Comparison of Low Glycaemic Index and High Glycaemic Index Potatoes in Relation to Satiety: A Single-Blinded, Randomised Crossover Study in Humans

High glycaemic index (GI) foods have been proposed to reduce satiety and thus promote overweight and obesity. Generally, potatoes have a high GI, but they also provide many beneficial nutrients and they are a highly important food source globally. In this study, we investigated how a low GI potato affected subjective satiety as compared to a high GI potato. Twenty healthy men (aged 18–40 years; body mass index (BMI) 18–27 kg/m²) participated in this single-blinded, controlled, randomised crossover trial. On each of the two trial days, the subjects were given a 500-gram portion of either a low or high GI potato variety (Carisma^® low GI and Arizona high GI). Subjective appetite sensations were measured at baseline and at +15 min, +45 min, +75 min, +105 min, and +135 min after consumption of the test meal until an ad libitum meal was served at +150 min. No significant differences in the primary endpoint, satiety, were found between the two potato varieties (all p > 0.05). Furthermore, no significant differences were found in the secondary endpoints; hunger, fullness, and prospective food consumption, or ad libitum energy intake (all p > 0.05). In conclusion, the results of this study do not indicate that the GI of potatoes is important for satiety in normal-weight men.

Effects of meal replacement therapy on metabolic outcomes in Thai patients with type 2 diabetes: A randomized controlled trial

Background:

A meal replacement (MR) with a low glycemic index (GI) is possibly beneficial for glycemic control. However, the effects of MR on diabetes mellitus have not been studied among Thai patients with type 2 diabetes (T2DM).

Aim:

To compare metabolic outcomes between T2DM patients receiving the new MR formula (ONCE PRO) and normal controlled diets.

Methods:

A multicenter, open-labeled, randomized controlled trial was conducted. Eligible patients received either ONCE PRO for one meal daily with controlled diets or only controlled diets for 3 months. The differences in metabolic profile between the baseline and end point of each group and between groups were measured.

Results:

110 participants were enrolled; the mean difference and standard deviation in hemoglobin A1C (HbA1c) (%) from baseline were –0.21 ± 0.78 (p = 0.060) and –0.27 ± 0.60 (p = 0.001) in the MR and control groups, respectively; however, there was no significant difference between groups (p = 0.637). Patients consuming a MR instead of breakfast had a significant decrease in HbA1c (p = 0.040). Body weight (BW) and body mass index (BMI) were significantly reduced in both groups. There were no significant change in waist circumference, fasting plasma glucose, total cholesterol and triglycerides. Low-density lipoprotein cholesterol (LDL-C) was significantly decreased in the MR group compared with the control group (p = 0.049).

Conclusions:

Short-term conventional diet control and the low-GI MR product were associated with a decreased BW and BMI. Changes in the other metabolic outcomes, HbA1c, total cholesterol and triglycerides, were comparable despite ONCE PRO as the MR having a better effect on LDL-C lowering.

Tamarindus indica seeds improve carbohydrate and lipid metabolism: An in vivo study

BACKGROUND

The tamarind seeds have a lot of nutrients that may be used to control cholesterol or glucose levels.

OBJECTIVE(S)

The effects of tamarind seeds (T) on lipid and carbohydrate metabolism in rats were studied. Rats were offered basal diet (BD) with T (2%, 4% or 8%) or without T.

MATERIALS AND METHODS

Feeding and growth performance in rats were measured and samples of liver and blood were analyzed for glycogen content and levels of cholesterol and glucose respectively.

RESULTS

The inclusion of T in the diet influences the feeding and growth performance in rats. The serum cholesterol level was reduced (p < 0.05) in Sprague Dawley (SD) rats fed on basal diet (BD) containing 4% and 8% T (0.24 ± 0.14 g/l and 0.31 ± 0.06 g/l respectively) compared to control (0.79 ± 0.04 g/l). The serum glucose levels in the spontaneous hypertensive rats (SHR) was lower (50.74 ± 2.50 mg/dl; p < 0.05) than control (93.52 ± 10.83 mg/dl) at 4% T. Incorporation of increasing doses of T resulted in linear increase of glycogen storage in livers of SD rats fed on BD and high sucrose diet.

CONCLUSION

Tamarind seeds can lower blood glucose and serum cholesterol and enhance storage of glycogen in rats.

Curcumin alleviates postprandial glycaemic response in healthy subjects: A cross-over, randomized controlled study

In the current study, we aimed to evaluate the effects of a single dose of curcumin and/or fish oil on postprandial glycaemic parameters in healthy individuals. This was a randomised, placebo-controlled and crossover study. Sixteen (n = 16) volunteers were randomised to receive placebo, curcumin (180 mg) tablets, fish oil (1.2 g long chain omega-3 polyunsaturated fatty acids) capsules and curcumin + fish oil prior to a standard meal on 4 test days separated by a week. Blood glucose, serum insulin and triglycerides were measured at intervals between 0–120 min. Difference between the treatments was measured using two-way repeated measures analysis of variance and pair-wise comparisons using Wilcoxon signed-rank or paired t-test as appropriate. Postprandial glucose concentrations were significantly lower in the curcumin (60.6%, P = 0.0007) and curcumin + fishoil group (51%, P = 0.002) groups at 60 min from baseline. Compared with placebo, area under the curve (AUC) for change in blood glucose concentration was reduced by curcumin (36%, P = 0.003) and curcumin + fishoil (30%, 0.004), but not fish oil alone (p = 0.105). Both curcumin (P = 0.01) and curcumin + fishoil (P = 0.03) treatments significantly lowered postprandial insulin (AUC) by 26% in comparison with placebo. Curcumin, but not fish oil, reduces postprandial glycaemic response and insulin demand for glucose control.

Replacing Sedentary Time: Meta-analysis of Objective-Assessment Studies

CONTEXT

The aim was to summarize estimates of the potential benefits for cardiometabolic risk markers and all-cause mortality of replacing time spent in sedentary behaviors with light-intensity physical activity or with moderate to vigorous physical activity, from studies using device-based measurement.

EVIDENCE ACQUISITION

Four databases covering the period up to December 2016 were searched and analyzed (February 2017). Data were extracted by two independent reviewers. For the meta-analyses, the estimated regression coefficients (β) and 95% CIs were analyzed for BMI, waist circumference, and high-density lipoprotein cholesterol. Pooled relative rate and 95% CIs were calculated for fasting glucose, fasting insulin, and homeostatic model assessment-insulin resistance values. Hazard ratios were extracted from studies of all-cause mortality risk.

EVIDENCE SYNTHESIS

Ten studies (with 17,390 participants) met the inclusion criteria. Reallocation of 30 minutes of sedentary time to light-intensity physical activity was associated with reductions in waist circumference, fasting insulin, and all-cause mortality risk; and with an increase in high-density lipoprotein cholesterol. Reallocating 30 minutes of sedentary time to moderate to vigorous physical activity was associated with reductions in BMI, waist circumference, fasting glucose, fasting insulin, and all-cause mortality (not pooled) and with an increase in high-density lipoprotein cholesterol.

CONCLUSIONS

Replacing sedentary time with either light-intensity physical activity or moderate to vigorous physical activity may be beneficial, but when sedentary time is replaced with moderate to vigorous physical activity, the predicted impacts are stronger and apparent for a broader range of risk markers. These findings point to potential benefits of replacing sedentary time with light-intensity physical activity, which may benefit those less able to tolerate or accommodate higher-intensity activities, including many older adults.

Determining the Glycaemic Index of Standard and High-Sugar Rodent Diets in C57BL/6 Mice

The glycaemic index (GI) is a useful tool to compare the glycaemic responses of foods. Numerous studies report the favorable effects of low GI diets on long term metabolic health compared with high GI diets. However, it has not been possible to link these effects to the GI itself because of other components such as macronutrients and dietary fibre, which are known to affect GI. This study aimed to create and evaluate isocaloric diets differing in GI independent of macronutrient and fibre content. The GIs of eight diets differing in carbohydrate source were evaluated in mice; cooked cornstarch (CC), raw cornstarch (RC), chow, maltodextrin, glucose, sucrose, isomaltulose, and fructose. A glucose control was also tested. The GIs of all eight diets were different from the GI of the glucose control (GI: 100; p < 0.0001). The GIs of the glucose (mean ± SEM: 52 ± 3), maltodextrin (52 ± 6), CC (50 ± 4), RC (50 ± 6), and chow (44 ± 4) diets were similar, while the GIs of the sucrose (31 ± 4), isomaltulose (24 ± 5), and fructose (18 ± 2) diets were lower than all other diets (p < 0.05). This is the first trial to report GI testing in vivo in mice, resulting in three main findings: chow is relatively high GI, the glucose availability of raw and cooked cornstarch is similar, and the GI of different sugar diets occur in the same rank order as in humans.