The acute effect of commercially available pulse powders on postprandial glycaemic response in healthy young men

Postprandial Blood Glucose and Insulin Response in Healthy Adults When Lentils Replace High-Glycemic Index Food Ingredients in Muffins, Chilies and Soups

OBJECTIVES

This study aimed to assess postprandial blood glucose response (PBGR), relative glycemic response (RGR) and insulin response when 25 g available carbohydrates (AC) is replaced with cooked lentils in the formulation of muffins, chilies and soups.

METHODS

In randomized, crossover studies, healthy adults consumed foods containing 25 g AC from green lentils, red lentils or a control (wheat muffin, n = 24; rice chili, n = 24; potato soup, n = 20). Blood collected at fasting and at 15, 30, 45, 60, 90 and 120 min was analyzed to derive the incremental area under the response curve (iAUC) for glucose, insulin, RGR and maximum concentration (CMAX). Treatment effects were assessed with repeated measures ANOVA.

RESULTS

A replacement of 25 g AC with green lentils significantly decreased glucose iAUC compared to chili and soup (p < 0.0001), but not muffin (p = 0.07) controls, while also eliciting a significantly lower insulin iAUC for all three foods (muffin p = 0.03; chili p = 0.0002; soup p < 0.0001). Red lentil foods significantly decreased glucose iAUC (muffin p = 0.02; chili p < 0.0001; soup p < 0.0001) compared to controls, with a significantly lower insulin iAUC for chili and soup (p < 0.0001) but not muffins (p = 0.09). The RGR for muffins, chilies and soups was 88, 58 and 61%, respectively, for green lentils, and 84, 48 and 49%, respectively, for red lentils.

CONCLUSIONS

PBGR, insulin and RGR are decreased when lentils are incorporated into food products, providing credible evidence to promote carbohydrate replacement with lentil-based foods.

Increasing particle size of oat flours decreases postprandial glycemia and increases appetite in healthy adults

Consumption of oats is associated with lowered risks of type 2 diabetes and obesity. However, many oat-based products (e.g., breakfast cereals) use finely milled flours but are associated with health claims based on oats of larger particle sizes. The objective of this study was to test the hypothesis that increasing oat flour particle size will result in lower postprandial glycemia and appetite. Using a randomized-controlled, crossover design, 20 participants (10 males, 10 females; age: 25.3 ± 1.0 years; body mass index: 23.2 ± 0.6 kg/m2) consumed a serving of porridge made using 40 g of coarse (675.7 ± 19.6 µm), whole (443.3 ± 36.2 µm), fine (96.0 ± 2.1 µm), or a commercial (375.9 ± 14.8 µm) oat flour unmatched in available carbohydrate, protein, and dietary fiber content. After a 12-hour overnight fast, blood glucose, insulin, and appetite were measured at 15 to 30-minute intervals over 120 minutes posttreatment consumption. Coarse and whole flours led to lower blood glucose between 30 and 60 minutes (P < .02). Blood glucose area under the curve (AUC) was lower after coarse than fine and commercial oat flours (P < 0.03), and after whole than fine oat flour (P < .002). Both coarse and whole oat flours resulted in lower insulin AUC than finer flours (P < .05). Appetite AUC was lower after the commercial than coarse flour (P < .007). Controlling milling to produce coarser oat flour to add to common foods may have health benefits. This study was registered at ClinicalTrials.gov (NCT05291351).

Minimal Effective Dose of Beans Required to Elicit a Significantly Lower Glycemic Response Than Commonly Consumed Starchy Foods: Predictions Based on In Vitro Digestion and Carbohydrate Analysis

Beans elicit lower glycemic responses (GRs) than other starchy foods, but the minimum effective dose (MED) to reduce GR is unknown. We sought to determine the MED of beans compared to common starchy foods. Overnight-fasted healthy volunteers consumed ¼c (phase 1, n = 24) or ½c (phase 2, n = 18) of black, cranberry, great northern, kidney, navy and pinto beans and corn, rice, pasta and potato (controls), with blood glucose measured before and for 2 h after eating. GRs (incremental areas under the curves, iAUCs) after beans were consumed were compared to those of controls by ANOVA followed by Dunnett's test. To qualify for MED, beans had to elicit an effective reduction in GR, defined as a statistically significant reduction in iAUC of ≥20% (i.e., a relative glycemic response, RGR, ≤80). Outcomes from in vitro digestion were compared with in vivo RGR. Both doses of all six beans effectively reduced GR versus all four starchy controls, except for ¼c and ½c cranberry and pinto vs. corn, ¼c great northern and navy vs. corn and ¼c navy and pinto vs. potato. MED criteria were met for 18 comparisons of the ¼c servings, with four of the remaining six met by the ½c servings. The overall mean ± SEM RGR vs. controls was similar for the ¼c and ½c servings: 53 ± 4% and 56 ± 3%, respectively. By multiple regression analysis, RGR = 23.3 × RDS + 8.3 × SDS - 20.1 × RS + 39.5 × AS - 108.2 (rapidly digested starch, p < 0.001; slowly digested starch, p = 0.054; resistant starch, p = 0.18; available sugars, p = 0.005; model r = 0.98, p = 0.001). RGR correlated with in vitro glucose release (r = 0.92, p < 0.001). The MED of beans is ¼ cup. For n = 30 comparisons (n = 24 beans vs. controls, n = 6 controls vs. each other), an effective reduction in GR was predicted from in vitro carbohydrate analysis with 86% sensitivity and 100% specificity.

Effect of processing and microstructural properties of chickpea-flours on in vitro digestion and appetite sensations

Nowadays, pulse flours are ingredients that are more and more used as substitutes in traditional staples (i.e., pasta, bread). In this study, cellular chickpea-flour was used as an ingredient to replace conventional raw-milled chickpea-flour in suspensions and semi-solid purees. The contribution of cellular integrity on in vitro macronutrient digestion and the subsequent effect on in vivo appetite sensations were investigated. Alternating the flour preparation sequence by interchanging hydrothermal treatment and mechanical disintegration (thermo-mechanical treatment) resulted in three chickpea-flours with distinct levels of cellular integrity, and thus nutrient accessibility. The study showed that cellular integrity in chickpea-flours was preserved upon secondary hydrothermal treatment and led to significant attenuation of in vitro macronutrient digestion as compared to conventional chickpea-flour. In a randomized crossover design, significant increase of mean in vivo subjective appetite sensations satiety and fullness along with decreases in hunger, desire to eat, and prospective food consumption were achieved when cellular integrity was kept without an effect on palatability and appearance of the purees (n = 22). In vitro digestion along with microstructural assessment confirmed the importance of cellular integrity for attenuating macronutrient digestion and thereby contributing to enhanced subjective satiety and fullness in pulses. Overall, this study highlights the promising potential of altarenating the flour preparation sequence resulting in macronutrient and energy-matched flours with different nutrient encapsulation which lead to different in vitro digestion kinetics and in vivo appetite sensations.

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).

Nutritional Composition and In Vitro Starch Digestibility of Crackers Supplemented with Faba Bean Whole Flour, Starch Concentrate, Protein Concentrate and Protein Isolate

The nutritional quality of common wheat-based foods can be improved by adding flours from whole pulses or their carbohydrate and protein constituents. Faba bean (Vicia faba L.) is a pulse with high protein concentration. In this study, prepared faba bean (FB) flours were added to wheat based baked crackers. Wheat cracker recipes were modified by substituting forty percent wheat flour with flours from whole faba bean, starch enriched flour (starch 60%), protein concentrate (protein 60%) or protein isolate (protein 90%). Baked crackers were ground into meal and analyzed for their macronutrient composition, starch characteristics and in vitro starch hydrolysis. Faba bean supplemented crackers had lower (p ≤ 0.001) total starch concentrations, but proportionally higher protein (16.8-43%), dietary fiber (6.7-12.1%), fat (4.8-7.1%) and resistant starch (3.2-6%) (p ≤ 0.001) than wheat crackers (protein: 16.2%, dietary fiber: 6.3%, fat: 4.2, resistant starch: 1.2%). The increased amylose, amylopectin B1- chain and fat concentration from faba bean flour and starch flour supplementation in cracker recipe contributed to increased resistant starch. Flours from whole faba bean, starch or protein fractions improved the nutritional properties and functional value of the wheat-based crackers. The analytical analysis describing protein, starch composition and structure and in vitro enzymatic hydrolysis advance understanding of factors that account for the in vivo benefits of faba bean flours added to crackers in human physiological functions as also previously shown for pasta. The findings can be used to guide development of improve nutritional quality of similar wheat-based food products.

A Review of the Relationship between Lentil Serving and Acute Postprandial Blood Glucose Response; Effects of Dietary Fibre, Protein and Carbohydrates

Pulse consumption has been shown to confer beneficial effects on blood glucose and insulin levels. Lentil consumption, in particular, consistently lowers acute blood glucose and insulin response when compared to starchy control foods. The mechanism by which lentils lower postprandial blood glucose response (PBGR) and insulin levels is unclear; however, evidence suggests that this effect may be linked to macronutrients and/or the amount of lentils consumed. This review attempts to consolidate existing studies that examined lentil consumption and glycemic and/or insulinemic responses and declared information on macronutrient composition and dietary fibre content of the foods tested. Collectively, these studies suggest that consumption of lentils reduces PBGR, with the minimum effective serving being ~110g cooked to reduce PBGR by 20%. Reductions in PBGR show modest-to-strong correlations with protein (45–57 g) and dietary fibre (22–30 g) content, but has weaker correlations with available carbohydrates. Increased lentil serving sizes were found to moderately influence relative reductions in peak blood glucose concentrations and lower the area under the blood glucose curve (BG AUC). However, no clear relationship was identified between serving and relative reductions in the BG AUC, making it challenging to characterize consistent serving–response effects.

Impact of food processing on postprandial glycaemic and appetite responses in healthy adults: a randomized, controlled trial

Chickpeas are among the lowest glycaemic index carbohydrate foods eliciting protracted digestion and enhanced satiety responses. In vitro studies suggest that mechanical processing of chickpeas significantly increases starch digestion. However, there is little evidence regarding the impact of processing on postprandial glycaemic response in response to chickpea intake in vivo. Therefore, the aim of this study was to determine the effect of mechanical processing on postprandial interstitial glycaemic and satiety responses in humans. In a randomised crossover design, thirteen normoglycaemic adults attended 4 separate laboratory visits following an overnight fast. On each occasion, one of four test meals, matched for available carbohydrate content and consisting of different physical forms of chickpeas (whole, puree, and pasta) or control (mashed potato), was administered followed by a subsequent standardised lunch meal. Continuous glucose monitoring captured interstitial glucose responses, accompanied by periodic venous blood samples for retrospective analysis of C-peptide, glucagon like peptide-1 (GLP-1), ghrelin, leptin, resistin, and cortisol. Subjective appetite responses were measured by Visual Analogue Scale (VAS). Postprandial glycaemic responses were comparable between chickpea treatments albeit significantly lower than the control (p < 0.001). Similarly, all chickpea treatments elicited significantly lower C-peptide and GLP-1 responses compared to the control (p < 0.05), accompanied by enhanced subjective satiety responses (p < 0.05), whilst no significant differences in satiety hormones were detected among different intervention groups (p > 0.05). Chickpea consumption elicits low postprandial glycaemic responses and enhanced subjective satiety responses irrespective of processing methods.

Canned Beans Decrease Serum Total and LDL Cholesterol in Adults with Elevated LDL Cholesterol in a 4-wk Multicenter, Randomized, Crossover Study

BACKGROUND

Practical risk reduction strategies are needed to address cardiovascular disease. Beans can decrease LDL cholesterol; however, research into different daily amounts and varieties is warranted.

OBJECTIVES

To examine the effects of canned beans (daily rotation of black, navy, pinto, dark red kidney, white kidney) in 1-cup (1CB, 180 g) and ½-cup (½CB, 90 g) daily amounts compared with a 1-cup white rice (WR) control on serum lipid and glycemic biomarkers in adults with elevated LDL cholesterol.

METHODS

Adults [n = 73, mean ± SD age: 48.1 ± 14.2 y; BMI (in kg/m2): 25.9 ± 4.22; fasting serum LDL cholesterol: 3.0-5.0 mmol/L] consumed 1CB, ½CB, and WR for 4-wk treatment periods separated by ≥4-wk washouts in a multicenter, randomized, crossover study. Fasting serum LDL cholesterol (primary outcome) and other lipids and glycemic biomarkers (secondary outcomes) were measured on study days 1 and 29 of each treatment period with study day 29 values compared using repeated-measures ANCOVA, including study day 1 values as covariates.

RESULTS

Treatment completion was n = 66 for 1CB, n = 68 for ½CB, and n = 64 for WR. Total cholesterol on study day 29 was lower for 1CB (P = 0.04) but not ½CB (P = 0.77) compared with WR (-5.46%, -2.74%, -0.65% changes from study day 1, respectively) and did not differ between 1CB and ½CB (P = 0.17). LDL cholesterol on study day 29 was also lower for 1CB (P = 0.002) but not ½CB (P = 0.30) compared with WR (-8.08%, -3.84%, +0.49% changes from study day 1, respectively) and did not differ between 1CB and ½CB (P = 0.11). Other lipids and glycemic biomarkers did not differ among treatments.

CONCLUSIONS

Consumption of 1 cup (180 g) of canned beans of multiple varieties decreased total and LDL cholesterol in adults with elevated LDL cholesterol, supporting a practical strategy for cardiovascular disease risk reduction. This trial was registered at clinicaltrials.gov as NCT03830970.

Acute effects of extruded pea fractions on glycemic response, insulin, appetite, and food intake in healthy young adults, results of a double-blind, randomized crossover trial

Benefits of pulse consumption on glycemic control are well established; however, research examining the effects of pulse fractions incorporated into extruded products is limited. In a randomized, repeated-measures crossover study, adults (n = 26) consumed cereals made with oat flour (control), oat flour and pea starch (starch), oat flour and pea protein (protein), oat flour, pea starch and pea protein (starch+protein), oat flour, pea fibre and pea protein (fibre+protein), and pea fibre, pea starch and pea protein (fibre+starch+protein). Blood glucose (BG) and insulin concentrations, and appetite incremental area under the curve (iAUC) were calculated before (0-120 min) and after (120-200 min) the ad libitum meal for measurement of food intake. Pre-meal, overall mean BG and iAUC were lower following the protein, starch+protein, protein+fibre, and the fibre+starch+protein cereals compared with the starch and control. For pre-meal overall mean insulin concentrations, fibre+protein led to a lower response compared with control, starch+protein, and protein cereals. Fibre+starch+protein also led to lower insulin compared with protein cereal. Pre-meal insulin iAUC was lower following fibre+protein compared with control and protein cereals. The inclusion of yellow pea protein and fibre in oat-based breakfast cereal reduces postprandial glycemia; however this effect is dependent on fraction type. ClinicalTrials.gov: NCT02366572. Novelty: Inclusion of pulse protein and fibre in oat flour-based breakfast cereal reduces postprandial glucose response. The glycemic benefits of whole pulses are at least somewhat retained in some pulse fractions.

Processing method modulates the effectiveness of black beans for lowering blood cholesterol in spontaneously hypertensive rats

BACKGROUND

Various foods are known to have beneficial effects on health when consumed whole; however, there is a trend towards preparing foods from processed ingredients, and it remains unclear whether the benefits of the whole food are retained. The purpose of this study was therefore to examine whether different processing techniques affect the lowering of cholesterol and the vascular effects of black beans (Phaseolus vulgaris L.).

RESULTS

Beans were prepared by overnight soaking and boiling - the standard method - and by micronization, extrusion, or dehulling and boiling, and they were then fine milled. Beans prepared by the standard method were also coarse milled. These five materials were incorporated into semi-purified diets (30% wt/wt) and fed to spontaneously hypertensive rats for 4 weeks. Body weight, blood pressure, and aorta morphology were unaltered by the diets. Fasting total cholesterol was significantly reduced in rats fed micronized beans compared with extruded beans (both fine-milled) or the bean-free diet, while boiling combined with coarse milling lowered low-density lipoprotein (LDL) cholesterol. The lack of cholesterol lowering in rats fed extruded bean compared to micronized was not explained by the amount or composition of dietary fiber or resistant starch. Differences in the polyphenolic profile as determined by high-performance liquid chromatography (HPLC) were also unable to explain the variations in cholesterol-lowering capacity.

CONCLUSION

The present study demonstrates that processing of black beans alters the health effects observed with the whole pulse, and suggests that products prepared with processed ingredients will need to be tested empirically to establish whether the biological effects are maintained in vivo. © 2020 Society of Chemical Industry.

Co-ingestion of NUTRALYS® pea protein and a high-carbohydrate beverage influences the glycaemic, insulinaemic, glucose-dependent insulinotropic polypeptide (GIP) and glucagon-like peptide-1 (GLP-1) responses: preliminary results of a randomised controlled trial

PURPOSE

Plant-based proteins may have the potential to improve glycaemic and gastrointestinal hormone responses to foods and beverages. The aim of this study was to investigate the effect of two doses of pea protein on postprandial glycaemic, insulinaemic, glucose-dependent insulinotropic polypeptide (GIP) and glucagon-like peptide-1 (GLP-1) response following a high-carbohydrate beverage intake in healthy individuals.

METHODS

In a single-blind, randomised, controlled, repeat measure, crossover design trial, thirty-one participants were randomly assigned to ingest 50 g glucose (Control), 50 g glucose with 25 g pea protein (Test 1) and 50 g glucose with 50 g pea protein (Test 2) on three separate days. Capillary blood samples (blood glucose and plasma insulin measurements) and venous blood samples (GIP and GLP-1 concentrations) were taken before each test and at fixed intervals for 180 min. The data were compared using repeated-measures ANOVA or the Friedman test.

RESULTS

Glucose incremental Area under the Curve (iAUC180) was significantly lower (p < 0.001) after Test 2 compared with Control (- 53%), after Test 1 compared with Control (- 31%) and after Test 2 compared with Test 1 (-32%). Insulin iAUC 180 was significantly higher (p < 0.001) for Test 1 (+ 28%) and Test 2 (+ 40%) compared with Control and for Test 2 (+ 17%) compared with Test 1 (p = 0.003). GIP and GLP-1 release showed no clear difference between Control and Pea protein drinks.

CONCLUSION

The consumption of pea protein reduced postprandial glycaemia and stimulated insulin release in healthy adults with a dose-response effect, supporting its role in regulating glycaemic and insulinaemic responses.

Faba bean meal, starch or protein fortification of durum wheat pasta differentially influence noodle composition, starch structure and in vitro digestibility

Faba bean (Vicia faba L.) flour, starch concentrate (60% starch), protein concentrate (~60% protein) and protein isolate (~85% protein) were added to replace one-quarter of durum wheat semolina to enrich the nutritional quality and physiological functions of durum wheat (Triticum turgidum L.) pasta. The raw pasta samples prepared with protein concentrate or isolate had higher (p ≤ 0.001) protein and lower (p ≤ 0.001) total starch concentrations, along with increased total dietary fiber and slowly digestible starch (p ≤ 0.001) than durum wheat semolina control or those with added whole faba-bean flour or isolated starch. The faba bean fortified pasta had altered starch with increased proportion of medium B-type glucan chains and long C-type glucan chains, reduced starch digestibility and were associated with glycaemia related effects in the human diet. The faba bean fortified pasta had increased protein and dietary fiber that influenced food intake and satiety. The results suggest differential contributions of food ingredients in human health outcomes.

The Role of Pulses in Cardiovascular Disease Risk for Adults With Diabetes

Cardiovascular disease (CVD) is a leading cause of death among adults while associated comorbidities like diabetes further increase risks of CVD-related complications and mortality. Strategies to prevent and manage CVD risk, such as dietary change, are a key component for CVD and diabetes prevention and management. Pulses, defined as the dried edible seeds of plants in the legume family, have received attention for their superior nutritional composition as high-fiber, low-glycemic index foods and have been studied for their potential to reduce CVD and diabetes risk. Both observational and experimental studies conducted among adults with and without diabetes have provided support for pulses in their ability to improve lipid profiles, glycemic control, and blood pressure, all of which are major modifiable risk factors of CVD. These capabilities have been attributed to various mechanisms associated with the nutrient and phytochemical composition of pulses. Overall, this evidence provides support for the consumption of pulses as an important dietary strategy to reduce risk of CVD for those living with and without diabetes.

Single Varietal Dry Bean (Phaseolus vulgaris L.) Pastas: Nutritional Profile and Consumer Acceptability

Dry beans (Phaseolus vulgaris L.) are a nutrient dense food rich in protein, dietary fiber, minerals, and folate. Consumption of dry beans is relatively low in the United States and this may be due in part to the lack of diversity in bean products beyond whole seeds. Products that incorporate beans in new forms, such as flours, offer the potential to increase dry bean utilization. In this study whole dry beans were milled into flour and used to make gluten free fresh pastas. Six bean varieties each from a different market class (white kidney, navy, otebo, cranberry, dark red kidney and black) were made into pasta. Their consumer appeal was compared to fresh wheat pasta and their nutritional value was compared to fresh wheat pasta and whole boiled beans. The dry bean pastas were nutritionally superior to wheat pasta with higher protein, ash, resistant starch and protein digestibility corrected amino acid score (PDCAAS) as well as lower total starch content. While consumers preferred the flavor, texture and appearance of the wheat pasta to the dry bean pasta, 36% of participants said they would definitely or probably purchase the dry bean pastas from the light colored beans. There was some loss of nutritional value of bean pasta vs. whole boiled beans but this can mostly be attributed to the bean pasta being 90% bean. These results suggest that single variety fresh dry bean pastas have commercial potential in the U.S. as healthy gluten free pasta options.

Cooked Red Lentils Dose-Dependently Modulate the Colonic Microenvironment in Healthy C57Bl/6 Male Mice

Dietary pulses, including lentils, are protein-rich plant foods that are enriched in intestinal health-promoting bioactives, such as non-digestible carbohydrates and phenolic compounds. The aim of this study was to investigate the effect of diets supplemented with cooked red lentils on the colonic microenvironment (microbiota composition and activity and epithelial barrier integrity and function). C57Bl/6 male mice were fed one of five diets: a control basal diet (BD), a BD-supplemented diet with 5, 10 or 20% cooked red lentils (by weight), or a BD-supplemented diet with 0.7% pectin (equivalent soluble fiber level as found in the 20% lentil diet). Red lentil supplementation resulted in increased: (1) fecal microbiota α-diversity; (2) abundance of short-chain fatty acid (SCFA)-producing bacteria (e.g., Prevotella, Roseburia and Dorea spp.); (3) concentrations of fecal SCFAs; (4) mRNA expression of SCFA receptors (G-protein-coupled receptors (GPR 41 and 43) and tight/adherens junction proteins (Zona Occulden-1 (ZO-1), Claudin-2, E-cadherin). Overall, 20% lentil had the greatest impact on colon health outcomes, which were in part explained by a change in the soluble and insoluble fiber profile of the diet. These results support recent public health recommendations to increase consumption of plant-based protein foods for improved health, in particular intestinal health.

Increased milk protein content and whey-to-casein ratio in milk served with breakfast cereal reduce postprandial glycemia in healthy adults: An examination of mechanisms of action

This study describes the effects on glycemic response and the underlying mechanisms of action of increasing the protein concentration and decreasing the casein-to-whey ratio in milk when consumed with a high glycemic breakfast cereal. Twelve healthy men and women, aged 18 to 30 yr and with a body mass index of 20 to 24.9 kg/m², consumed (in random order) milk beverages (250 mL) containing either 3.1 or 9.3% protein and casein-to-whey ratios of either 80:20 or 40:60. We measured postprandial appetite, glucose, regulatory hormones, and stomach emptying rate over 200 min, as well as food intake at an ad libitum meal at 120 min. Although pre-meal appetite was suppressed to a greater extent with milk beverages that had high (9.3%) compared with regular (3.1%) protein content, food intake was similar among all 4 treatments. Pre-meal mean blood glucose was lower with beverages that had high rather than regular milk protein content, with the lowest glucose peaks after the high milk protein treatment with the 40:60 casein-to-whey ratio. Pre-meal insulin and C-peptide levels were not affected by milk protein content or casein-to-whey ratio, but pre-meal glucagon-like peptide 1 was higher after the treatment containing high milk protein and the 40:60 casein-to-whey ratio, and pre-meal cholecystokinin was higher after the treatments containing high milk protein content. Plasma paracetamol response was also lower after the treatments containing high compared with regular milk protein content. When consumed with carbohydrate, milk beverages with high protein content and (to a lesser extent) a decreased casein-to-whey ratio lowered postprandial glycemia through insulin-independent mechanisms, primarily associated with delayed stomach emptying.

Understanding the Relations Among the Storage, Soaking, and Cooking Behavior of Pulses: A Scientific Basis for Innovations in Sustainable Foods for the Future

The world faces challenges that require sustainable solutions: food and nutrition insecurity; replacement of animal-based protein sources; and increasing demand for convenient, nutritious, and health-beneficial foods; as well as functional ingredients. The irrefutable potential of pulses as future sustainable food systems is undermined by the hardening phenomenon that develops upon their storage under adverse conditions of temperature and relative humidity. Occurrence of this phenomenon indicates storage instability. In this review, the application of a material science approach, in particular the glass transition temperature concept, is presented to explain phenomena of storage instability such as the occurrence of hardening and loss of viability under adverse storage conditions. In addition to storage (in)stability, application of this concept during processing of pulses is discussed. The state-of-the-art on how hardening occurs, that is, mechanistic insights, is provided, including a critical evaluation of some of the existing postulations using recent research findings. Moreover, the influence of hardening on the properties and processing of pulses is included. Prevention of hardening and curative actions for pulses affected by the hardening phenomenon are described in addition to the current trends on uses of pulses and pulse-derived products. Based on the knowledge progress presented in this review, suggestions for the future include: first, the need for innovation toward implementation of recommended solutions for the prevention of hardening; second, the optimization of the identified most effective and efficient curative action against hardening; and third, areas to focus on for elucidation of mechanisms of hardening, although existing analytical methods require advancement.

Faba bean protein flours added to pasta reduce post-ingestion glycaemia, and increase satiety, protein content and quality

Durum Wheat Semolina (DWS) pastas with added fababean (FB) protein flour reduce postprandial blood glucose and appetite and have higher nutritional quality.

Chickpea supplementation prior to colitis onset reduces inflammation in dextran sodium sulfate-treated C57Bl/6 male mice

The potential for a chickpea-supplemented diet (rich in fermentable nondigestible carbohydrates and phenolic compounds) to modify the colonic microenvironment and attenuate the severity of acute colonic inflammation was investigated. C57Bl/6 male mice were fed a control basal diet or basal diet supplemented with 20% cooked chickpea flour for 3 weeks prior to acute colitis onset induced by 7-day exposure to dextran sodium sulfate (DSS; 2% w/v in drinking water) and colon and serum levels of inflammatory mediators were assessed. Despite an equal degree of DSS-induced epithelial barrier histological damage and clinical symptoms between dietary groups, biomarkers of the ensuing inflammatory response were attenuated by chickpea pre-feeding, including reduced colon tissue activation of nuclear factor kappa B and inflammatory cytokine production (tumor necrosis factor alpha and interleukin (IL)-18). Additionally, colon protein expression of anti-inflammatory (IL-10) and epithelial repair (IL-22 and IL-27) cytokines were increased by chickpea pre-feeding. Furthermore, during acute colitis, chickpea pre-feeding increased markers of enhanced colonic function, including Relmβ and IgA gene expression. Collectively, chickpea pre-feeding modulated the baseline function of the colonic microenvironment, whereby upon induction of acute colitis, the severity of the inflammatory response was attenuated.

Effect of Processing on Postprandial Glycemic Response and Consumer Acceptability of Lentil-Containing Food Items

The consumption of pulses is associated with many health benefits. This study assessed post-prandial blood glucose response (PPBG) and the acceptability of food items containing green lentils. In human trials we: (i) defined processing methods (boiling, pureeing, freezing, roasting, spray-drying) that preserve the PPBG-lowering feature of lentils; (ii) used an appropriate processing method to prepare lentil food items, and compared the PPBG and relative glycemic responses (RGR) of lentil and control foods; and (iii) conducted consumer acceptability of the lentil foods. Eight food items were formulated from either whole lentil puree (test) or instant potato (control). In separate PPBG studies, participants consumed fixed amounts of available carbohydrates from test foods, control foods, or a white bread standard. Finger prick blood samples were obtained at 0, 15, 30, 45, 60, 90, and 120 min after the first bite, analyzed for glucose, and used to calculate incremental area under the blood glucose response curve and RGR; glycemic index (GI) was measured only for processed lentils. Mean GI (± standard error of the mean) of processed lentils ranged from 25 ± 3 (boiled) to 66 ± 6 (spray-dried); the GI of spray-dried lentils was significantly (p < 0.05) higher than boiled, pureed, or roasted lentil. Overall, lentil-based food items all elicited significantly lower RGR compared to potato-based items (40 ± 3 vs. 73 ± 3%; p < 0.001). Apricot chicken, chicken pot pie, and lemony parsley soup had the highest overall acceptability corresponding to “like slightly” to “like moderately”. Processing influenced the PPBG of lentils, but food items formulated from lentil puree significantly attenuated PPBG. Formulation was associated with significant differences in sensory attributes.

Carbohydrate Replacement of Rice or Potato with Lentils Reduces the Postprandial Glycemic Response in Healthy Adults in an Acute, Randomized, Crossover Trial

Background

The postprandial blood glucose response (PBGR) following carbohydrate replacement of high-glycemic index (GI) foods with pulses, in a mixed meal, has not been accurately defined.

Objective

We aimed to determine the extent to which PBGR and relative glycemic response (RGR) are lowered when half of the available carbohydrate (AC) from rice or potato is replaced with cooked lentils.

Methods

Using a crossover design, 2 groups of 24 healthy adults randomly consumed 50 g AC from control white rice alone [mean ± SD body mass index (BMI, in kg/m2): 24.3 ± 0.5; mean ± SD age: 27.7 ± 1.2 y], instant potato alone (BMI: 24.0 ± 0.5; age: 27.4 ± 1.2 y), or the same starch source in a 50:50 AC combination with each of 3 types of commercially available lentils (large green, small green, split red). Fasting and postprandial blood samples were analyzed for glucose and insulin, and used to derive incremental area under the curve (iAUC), RGR, and maximum concentration (Cmax). Treatment effects were assessed with the use of repeated-measures ANOVA within the rice and potato treatments.

Results

In comparison to rice alone, blood glucose iAUC and Cmax (P < 0.001) were lowered after consumption of rice with large green (P = 0.057), small green (P = 0.002), and split red (P = 0.006) lentils. Blood glucose iAUC and Cmax were also significantly lowered (P < 0.0001) after consumption of potato combined with each lentil, compared to potato alone. Plasma insulin iAUC and Cmax were significantly (P < 0.001) decreased when lentils were combined with potato, but not with rice. The RGRs of rice and potato were lowered by ∼20% and 35%, respectively, when half of their AC was replaced with lentils.

Conclusions

Replacing half of the AC from high-GI foods with lentils significantly attenuates PBGR in healthy adults; this can contribute to defining a health claim for pulses and blood glucose lowering. This trial was registered at clinicaltrials.gov as NCT02426606.

Navy and black bean supplementation attenuates colitis-associated inflammation and colonic epithelial damage

The enriched levels of nondigestible fermentable carbohydrates and phenolic compounds found in common beans can exert immunomodulatory effects within the colon that improve gut health and mitigate the severity of colitis-associated inflammatory pathology. Prior to acute colitis onset, C57Bl/6 mice were prefed isocaloric 20% cooked navy bean (NB) or black bean (BB) diets for 3 weeks and switched to control basal diet (BD) 24 h prior to colitis induction via 5-day exposure to dextran sodium sulfate (2% w/v in drinking water)+3 days of fresh water. The severity of the acute colitis phenotype was attenuated by bean prefeeding, evidenced by reduced colon tissue inflammatory transcription factor activation (NFκB, STAT3) and inflammatory mediator levels in the colon (IL-1β, IL-6, IL-18 and MCP-1) and serum (TNFα, IL-6, IL-1β, MCP-1) versus BD (P≤.05). Additionally, biomarkers of enhanced wound repair responses were increased by bean prefeeding including colon tissue protein levels of IL-22, IL-27 and activated (i.e., GTP-bound) Cdc42 and Rac1 versus BD (P≤.05). mRNA expressions of genes involved in normal colonic epithelial function and the promotion of epithelial barrier integrity, defense and/or restitution and wound closure including MUC1, RELMβ, IgA and REG3γ were all increased in NB and BB prefed mice versus BD (P≤.05). Collectively, bean supplementation prior to colitis induction (i.e., mimicking disease relapse) primes the colonic microenvironment to attenuate the severity of the colitis inflammatory phenotype and maintain aspects of epithelial barrier function.

Navy and black bean supplementation primes the colonic mucosal microenvironment to improve gut health

Common beans (Phaseolus vulgaris L.) are enriched in non-digestible fermentable carbohydrates and phenolic compounds that can modulate the colonic microenvironment (microbiota and host epithelial barrier) to improve gut health. In a comprehensive assessment of the impact of two commonly consumed bean varieties (differing in levels and types of phenolic compounds) within the colonic microenvironment, C57Bl/6 mice were fed diets supplemented with 20% cooked navy bean (NB) or black bean (BB) flours or an isocaloric basal diet control (BD) for 3 weeks. NB and BB similarly altered the fecal microbiota community structure (16S rRNA sequencing) notably by increasing the abundance of carbohydrate fermenting bacteria such as Prevotella, S24-7 and Ruminococcus flavefaciens, which coincided with enhanced short chain fatty acid (SCFA) production (microbial-derived carbohydrate fermentation products) and colonic expression of the SCFA receptors GPR-41/-43/-109a. Both NB and BB enhanced multiple aspects of mucus and epithelial barrier integrity vs. BD including: (i) goblet cell number, crypt mucus content and mucin mRNA expression, (ii) anti-microbial defenses (Reg3γ), (iii) crypt length and epithelial cell proliferation, (iv) apical junctional complex components (occludin, JAM-A, ZO-1 and E-cadherin) mRNA expression and (v) reduced serum endotoxin concentrations. Interestingly, biomarkers of colon barrier integrity (crypt height, mucus content, cell proliferation and goblet cell number) were enhanced in BB vs. NB-fed mice, suggesting added benefits attributable to unique BB components (e.g., phenolics). Overall, NB and BB improved baseline colonic microenvironment function by altering the microbial community structure and activity and promoting colon barrier integrity and function; effects which may prove beneficial in attenuating gut-associated diseases.

Can pulses play a role in improving cardiometabolic health? Evidence from systematic reviews and meta-analyses

Obesity, diabetes, and cardiovascular disease (CVD) present important unmet prevention and treatment challenges. Dietary pulses are sustainable, affordable, and nutrient-dense foods that have shown a wide range of health benefits in the prevention and management of these conditions. Despite these findings, recommendations for pulse intake continue to vary across chronic disease guidelines, and intake levels continue to remain low. Here, we summarize findings from recent systematic reviews and meta-analyses assessing the relationship between dietary pulse consumption and cardiometabolic health and assess the overall strength of the evidence using the Grading of Recommendations, Assessment, Development, and Evaluation tool. We conclude that systematic reviews and meta-analyses of prospective cohort studies assessing the relationship between legumes and the risk of coronary heart disease appear to provide moderate-quality evidence of a benefit, and several systematic reviews and meta-analyses of randomized controlled trials assessing the effect of pulses on cardiometabolic risk factors provide low- to moderate-quality evidence of a benefit. There remains an urgent need, however, for more high-quality prospective cohort studies and large, high-quality, randomized trials to clarify the benefits of dietary pulses in the prevention and management of overweight/obesity, diabetes, and CVD.

A Pilot Randomized Controlled Clinical Trial to Assess Tolerance and Efficacy of Navy Bean and Rice Bran Supplementation for Lowering Cholesterol in Children

Background: Navy beans and rice bran demonstrate efficacy to regulate serum cholesterol in hypercholesterolemic adults; however, the cardiovascular disease (CVD) protective properties of these foods in children are unknown and merit investigation. Objective: The objectives were to determine whether cooked navy bean powder (NBP) and/or heat-stabilized rice bran (RB) supplementation is tolerable, improves dietary fiber intake in children, and modulates lipid profiles. Methods: Children aged 8 to 13 years at risk for CVD due to abnormal lipids were recruited. Elevated cholesterol levels were defined as total cholesterol ≥180 mg/dL and high-density lipoprotein (HDL) <60 mg/dL; low-density lipoprotein (LDL) ≥100 mg/dL and HDL <60 mg/dL; or non-HDL >100 mg/dL and HDL <60 mg/dL. Participants completed a pilot 4-week, randomized controlled, 4-arm dietary intervention. They consumed study-provided muffins or a smoothie daily that included 0 g NBP or RB (control), 17.5 g NBP, 15 g RB, or a combination 9 g NBP + 8 g RB. Fasting blood was collected at baseline and week 4. Participants also completed 3-day food logs and gastrointestinal health questionnaires. Results: Thirty-eight children completed the trial (n = 9 control, n = 10 NBP, n = 9 RB, and n = 10 NBP + RB groups). Only 3 participants withdrew due to noncompliance of required food consumption. Participants in the intervention groups significantly increased intake of NBP and RB at week 4 (p≤.01). The NBP and NBP + RB groups increased total fiber intake from baseline to week 4 (p=.02 and p=<.01, respectively). HDL-cholesterol was higher in NBP-group participants compared to control at week 4 (P = .02). Conclusion: Increasing NBP and/or RB intake is tolerable for children, and our findings suggest higher daily intakes are needed for a longer duration to induce favorable changes across multiple serum lipid parameters.

The Role of Pulses in the Dietary Management of Diabetes

Pulses are highly nutritious foods that are included as part of Canada's Food Guide to promote healthful eating, and they have established health benefits that can contribute to the dietary management of diabetes. A review of studies that have examined the effects of pulse consumption on health outcomes, integral to the management of diabetes, provides credible evidence for improvements in glycemic control, reduction of blood lipids and regulation of body weight. Results from acute feeding trials suggest that postprandial blood glucose response is significantly attenuated by a single pulse serving of between three-quarters and 1 cup. At lower doses, pulses attenuate postprandial blood glucose response more than similar amounts of starchy foods. Long-term pulse consumption of 5 cups per week appears to result consistently in improvements in glycemic control. There is high-quality evidence that supports a role for pulse consumption in the reduction of risk for cardiovascular disease; this provides a sound rationale for the regular incorporation of pulses at about two-thirds of a cup daily in the management of hyperlipidemia in persons with type 2 diabetes. Pulse consumption can contribute to improving satiety, reducing food intake and regulating body weight, which can reduce obesity risk and, in turn, improve diabetes management. Collectively, available evidence provides very good support for a role of regular pulse consumption in the prevention and management of diabetes.

A Randomized Controlled Trial to Increase Navy Bean or Rice Bran Consumption in Colorectal Cancer Survivors

Consumption of navy beans (NB) and rice bran (RB) have been shown to inhibit colon carcinogenesis. Given the overall poor diet quality in colorectal cancer (CRC) survivors and low reported intake of whole grains and legumes, practical strategies to increase consumption merit attention. This study determined feasibility of increasing NB or RB intake in CRC survivors to increase dietary fiber and examined serum inflammatory biomarkers and telomere lengths. Twenty-nine subjects completed a randomized controlled trial with foods that included cooked NB powder (35 g/day), heat-stabilized RB (30 g/day), or no additional ingredient. Fasting blood, food logs, and gastrointestinal health questionnaires were collected. The amount of NB or RB consumed equated to 4-9% of subjects' daily caloric intake and no major gastrointestinal issues were reported with increased consumption. Dietary fiber amounts increased in NB and RB groups at Weeks 2 and 4 compared to baseline and to control (P ≤ 0.01). Telomere length correlated with age and HDL cholesterol at baseline, and with improved serum amyloid A (SAA) levels at Week 4 (P ≤ 0.05). This study concludes feasibility of increased dietary NB and RB consumption to levels associated with CRC chemoprevention and warrants longer-term investigations with both foods in high-risk populations that include cancer prevention and control outcomes.