Glycemic and Insulinemic Responses of Vegetables and Beans Powders Supplemented Chapattis in Healthy Humans: A Randomized, Crossover Trial

Acute Effects of Dietary Fiber in Starchy Foods on Glycemic and Insulinemic Responses: A Systematic Review of Randomized Controlled Crossover Trials

Dietary fiber (DF) consumption has been associated with improved glycemic control in epidemiological and long-term interventional studies. However, its acute effects are not yet clear. This systematic review aims to elucidate the postprandial effects of DF in starchy products on glycemia and insulinemia. An electronic search of databases was conducted, and forty-one records met the inclusion criteria and underwent a risk-of-bias assessment. It was shown that soluble DF does not clearly affect glycemia in individuals with normal weight, while resistant starch may be more effective in flattening glycemic responses. Concerning insulinemia, both soluble DF and resistant starch have mixed results, with either favorable or no effects. Data on insoluble DF and glucose metabolism are scarce. The same mixed results for glycemia can be seen in healthy volunteers with overweight/obesity, while resistant starch seems to improve insulinemic responses. Finally, more studies need to examine the acute effects of DF in starchy foods on glucose metabolism and insulin secretion in individuals facing glucose abnormalities. Additionally, more studies are needed to prove whether ingesting high-fiber carbohydrate-containing products per se can result in blunted glycemic and insulinemic responses and which DF type and amount are more effective.

Impact of a Low-Insulin-Stimulating Bread on Weight Development-A Real Life Randomised Controlled Trial

The impact on body weight development is usually analysed by comparing different diet types. Our approach was to change only one component, namely bread, common to most diets. In a single-centre triple-blind randomised controlled trial the effects of two different breads on body weight were analyzed without further lifestyle modification. Overweight adult volunteers (n = 80) were randomised 1:1 to exchange previously consumed breads for either a rye bread from milled whole grain (control) or a medium-carbohydrate, low-insulin-stimulating bread (intervention). Pre-tests demonstrated that the two bread types strongly differed in the glucose and insulin response elicited, but had similar energy content, texture and taste. The primary endpoint was the estimated treatment difference (ETD) in change of body weight after 3 months of treatment. Whereas body weight remained unchanged in the control group (-0.1 ± 2.0 kg), significant weight reduction was observed in the intervention group (-1.8 ± 2.9 kg), with an ETD of -1.7 ± 0.2 kg (p = 0.007), that was more pronounced in participants ≥ 55 years (-2.6 ± 3.3 kg), paralleled by significant reductions in body mass index and hip circumference. Moreover, in the intervention group, the percentage of participants with significant weight loss (≥1 kg) was twice as high as in the control group (p < 0.001). No other statistically significant changes in clinical or lifestyle parameters were noted. Simply exchanging a common insulinogenic bread for a low-insulin-stimulating bread demonstrates potential to induce weight loss in overweight persons, especially those at older age.

Glycaemic Index of Gluten-Free Biscuits with Resistant Starch and Sucrose Replacers: An In Vivo and In Vitro Comparative Study

The glycaemic index (GI) is used to demonstrate the tendency of foods to increase blood glucose and is thus an important characteristic of newly formulated foods to tackle the rising prevalence of diabetics and associated diseases. The GI of gluten-free biscuits formulated with alternate flours, resistant starch and sucrose replacers was determined using in vivo methods with human subjects. The relationship between in vivo GI values and the predicted glycaemic index (pGI) from the in vitro digestibility-based protocols, generally used by researchers, was established. The in vivo data showed a gradual reduction in GI with increased levels of sucrose substitution by maltitol and inulin with biscuits where sucrose was fully replaced, showing the lowest GI of 33. The correlation between the GI and pGI was food formulation-dependent, even though GI values were lower than the reported pGI. Applying a correction factor to pGI tend to close the gap between the GI and pGI for some formulations but also causes an underestimation of GI for other samples. The results thus suggest that it may not be appropriate to use pGI data to classify food products according to their GI.

Substituting Whole Wheat Flour with Pigeon Pea (Cajanus cajan) Flour in Chapati: Effect on Nutritional Characteristics, Color Profiles, and In Vitro Starch and Protein Digestion

Pigeon pea (Cajanus cajan (L.) Millsp.), a potential legume as an economical source of protein, is commonly cultivated in tropical and subtropical regions of the world. Therefore, pigeon pea may be potentially used as a substitute to improve the nutritional profile of foods. In the present study, the effect of substitution of whole wheat flour (WWF) with 20% and 40% pigeon pea flour (PPF) on the nutritional properties, color profiles, and starch and protein digestibility of chapati was investigated. The results showed that PPF had higher protein content but less carbohydrate than WWF. The protein content of chapati substituted with 20% and 40% PPF increased by 1.18 and 1.34 times, respectively, compared to WWF chapati, along with a marked decrease in carbohydrate content. Analyses further revealed an increase in the lightness and yellowness and a decrease in the redness of the chapati. Furthermore, glucose release from chapati with 20% and 40% PPF under simulated digestion was attenuated, corresponding to decreased hydrolysis and a predicted glycemic index. In the 40% PPF chapati, a significant reduction in slowly digestible starch (SDS) with increased resistant starch (RS) proportions was achieved without altering the effect on rapidly digestible starch (RDS). In addition, the level of amino-group residues was markedly elevated in 20% and 40% PPF substituted chapati compared to WWF chapati. These findings suggest that PPF can serve as a promising plant-based alternative ingredient to improve the nutrient value of chapati by reducing starch and increasing protein digestibility.

Short-Term Effects of Traditional Greek Meals: Lentils with Lupins, Trahana with Tomato Sauce and Halva with Currants and Dried Figs on Postprandial Glycemic Responses-A Randomized Clinical Trial in Healthy Humans

Low glycemic index (GI) diets have been associated with decreased chronic disease risk. In a randomized, cross-over study we investigated the GI and glycemic response to three traditional Greek mixed meals: Lentils, Trahana, and Halva. Twelve healthy, fasting individuals received isoglucidic test meals (25 g available carbohydrate) and 25 g glucose reference, in random order. GI was calculated and capillary blood glucose (BG) samples were collected at 0-120 min after meal consumption. Subjective appetite ratings were assessed. All three tested meals provided low GI values. Lentils GI was 27 ± 5, Trahana GI was 42 ± 6, and Halva GI was 52 ± 7 on glucose scale. Peak BG values were lowest for Lentils, followed by Trahana and then by Halva (p for all <0.05). Compared to the reference food, BG concentrations were significantly lower for all meals at all time-points (p for all <0.05). Lentils provided lower glucose concentrations at 30 and 45 min compared to Trahana (p for all <0.05) and at 30, 45, and 60 min compared to Halva (p for all <0.05). BG concentrations did not differ between Trahana and Halva at all time points. No differences were observed for fasting BG, time to peak rise for BG, and subjective appetite ratings. In conclusion, all three mixed meals attenuated postprandial glycemic response in comparison to glucose, which may offer advantages to glycemic control.

Pulse consumption improves indices of glycemic control in adults with and without type 2 diabetes: a systematic review and meta-analysis of acute and long-term randomized controlled trials

PURPOSE

Findings from randomized controlled trials (RCTs) evaluating the effect of pulse intake on glycemic control are inconsistent and conclusive evidence is lacking. The aim of this study was to systematically review the impact of pulse consumption on post-prandial and long-term glycemic control in adults with and without type 2 diabetes (T2D).

METHODS

Databases were searched for RCTs, reporting outcomes of post-prandial and long-term interventions with different pulse types on parameters of glycemic control in normoglycemic and T2D adults. Effect size (ES) was calculated using random effect model and meta-regression was conducted to assess the impact of various moderator variables such as pulse type, form, dose, and study duration on ES.

RESULTS

From 3334 RCTs identified, 65 studies were eligible for inclusion involving 2102 individuals. In acute RCTs, pulse intake significantly reduced peak post-prandial glucose concentration in participants with T2D (ES  - 2.90; 95%CI  - 4.60,  - 1.21; p ≤ 0.001; I2 = 93%) and without T2D (ES  - 1.38; 95%CI  - 1.78,  - 0.99; p ≤ 0.001; I2 = 86%). Incorporating pulse consumption into long-term eating patterns significantly attenuated fasting glucose in normoglycemic adults (ES  - 0.06; 95%CI  - 0.12, 0.00; p ≤ 0.05; I2 = 30%). Whereas, in T2D participants, pulse intake significantly lowered fasting glucose (ES  - 0.54; 95%CI  - 0.83,  - 0.24; p ≤ 0.001; I2 = 78%), glycated hemoglobin A1c (HbA1c) (ES  - 0.17; 95%CI  - 0.33, 0.00; p ≤ 0.05; I2 = 78) and homeostatic model assessment of insulin resistance (HOMA-IR) (ES  - 0.47; 95%CI  - 1.25,  - 0.31; p ≤ 0.05; I2 = 79%).

CONCLUSION

Pulse consumption significantly reduced acute post-prandial glucose concentration > 1 mmol/L in normoglycemic adults and > 2.5 mmol/L in those with T2D, and improved a range of long-term glycemic control parameters in adults with and without T2D. PROSPERO REGISTRY NUMBER: (CRD42019162322).

Red and white cabbages: An updated comparative review of bioactives, extraction methods, processing practices, and health benefits

Red and white cabbages (Brassica oleracea var. capitata f. alba and rubra, respectively) are two of the most commercially valued vegetables in crucifers, well-recognized for their unique sensory and nutritive attributes in addition to a myriad of health-promoting benefits. The current review addressed the differential qualitative/quantitative phytochemical make-ups for the first time for better utilization as nutraceuticals and to identify potential uses based on the chemical makeup of both cultivars (cvs.). In addition, extraction methods are compared highlighting their advantages and/or limitations with regards to improving yield and stability of cabbage bioactives, especially glucosinolates. Besides, the review recapitulated detailed action mechanism and safety of cabbage bioactives, as well as processing technologies to further improve their effects are posed as future perspectives. White and red cabbage cvs. revealed different GLSs profile which affected by food processing, including enzymatic hydrolysis, thermal breakdown, and leaching. In addition, the red cultivar provides high quality pigment for industrial applications. Moreover, non-conventional modern extraction techniques showed promising techniques for the recovery of their bioactive constituents compared to solvent extraction. All these findings pose white and red cabbages as potential candidates for inclusion in nutraceuticals and/or to be commercialized as functional foods prepared in different culinary forms.

Determining the glycaemic responses of foods: conventional and emerging approaches

A low-glycaemic diet is crucial for those with diabetes and cardiovascular diseases. Information on the glycaemic index (GI) of different ingredients can help in designing novel food products for such target groups. This is because of the intricate dependency of material source, composition, food structure and processing conditions, among other factors, on the glycaemic responses. Different approaches have been used to predict the GI of foods, and certain discrepancies exist because of factors such as inter-individual variation among human subjects. Besides other aspects, it is important to understand the mechanism of food digestion because an approach to predict GI must essentially mimic the complex processes in the human gastrointestinal tract. The focus of this work is to review the advances in various approaches for predicting the glycaemic responses to foods. This has been carried out by detailing conventional approaches, their merits and limitations, and the need to focus on emerging approaches. Given that no single approach can be generalised to all applications, the review emphasises the scope of deriving insights for improvements in methodologies. Reviewing the conventional and emerging approaches for the determination of GI in foods, this detailed work is intended to serve as a state-of-the-art resource for nutritionists who work on developing low-GI foods.

Effect of sucrose replacement and resistant starch addition on textural properties of gluten-free doughs and biscuits

There is a need to develop low-sugar healthy products. The aim of this research was to evaluate the effect of maltitol and inulin as sucrose replacement alongside resistant starch (RS) and green banana flour (GBF) on the texture and physical properties of gluten-free doughs and biscuits formulated with buckwheat, sorghum and lentil flours. These properties are important to predict the dough workability, how easy the biscuits could be mass-produced and determine consumers’ acceptability. Results showed that partial and complete substitution of sucrose could be achieved and appropriate concentration of resistant starch or green banana flour contributed to better dough and biscuit texture. RS content showed the biggest influence on dough stickiness and biscuit hardness and could be used to correct the negative effect of sucrose replacement and to maximise both the dough processability and biscuit acceptability.

Gut-Based Strategies to Reduce Postprandial Glycaemia in Type 2 Diabetes

Postprandial glycemic control is an important target for optimal type 2 diabetes management, but is often difficult to achieve. The gastrointestinal tract plays a major role in modulating postprandial glycaemia in both health and diabetes. The various strategies that have been proposed to modulate gastrointestinal function, particularly by slowing gastric emptying and/or stimulating incretin hormone GLP-1, are summarized in this review.