The Metabolic Effects of Oats Intake in Patients with Type 2 Diabetes: A Systematic Review and Meta-Analysis

Plant-Based Diets and Phytochemicals in the Management of Diabetes Mellitus and Prevention of Its Complications: A Review

Diabetes mellitus (DM) is currently regarded as a global public health crisis for which lifelong treatment with conventional drugs presents limitations in terms of side effects, accessibility, and cost. Type 2 diabetes (T2DM), usually associated with obesity, is characterized by elevated blood glucose levels, hyperlipidemia, chronic inflammation, impaired β-cell function, and insulin resistance. If left untreated or when poorly controlled, DM increases the risk of vascular complications such as hypertension, nephropathy, neuropathy, and retinopathy, which can be severely debilitating or life-threatening. Plant-based foods represent a promising natural approach for the management of T2DM due to the vast array of phytochemicals they contain. Numerous epidemiological studies have highlighted the importance of a diet rich in plant-based foods (vegetables, fruits, spices, and condiments) in the prevention and management of DM. Unlike conventional medications, such natural products are widely accessible, affordable, and generally free from adverse effects. Integrating plant-derived foods into the daily diet not only helps control the hyperglycemia observed in DM but also supports weight management in obese individuals and has broad health benefits. In this review, we provide an overview of the pathogenesis and current therapeutic management of DM, with a particular focus on the promising potential of plant-based foods.

A Randomized Controlled Trial to Assess the Feasibility and Practicability of an Oatmeal Intervention in Individuals with Type 2 Diabetes: A Pilot Study in the Outpatient Sector

Background/Objectives: The aim of this study was to investigate the feasibility and practicability of repeated three-day sequences of a hypocaloric oat-based nutrition intervention (OI) in insulin-treated outpatients with type 2 diabetes and severe insulin resistance. Methods: A randomized, two-armed pilot study was conducted with three months of intervention and three months follow-up with 17 participants with insulin resistance (≥1 IU/kg body weight). Group A (n = 10) performed one sequence of OI; Group B (n = 7) performed two sequences monthly. A sequence was 3 consecutive days of oat consumption with approximately 800 kcal/d. The main objective was to assess feasibility (≥70% completers) and practicability regarding performance aspects. Biomedical parameters such as HbA1 c were observed. To evaluate the state of health, a standardized questionnaire was used (EQ-5 D). Results: OI was feasible (13/17 completer participants (76.5%): 70.0% Group A, 85.7% Group B). Individually perceived practicability was reported as good by 10/16 participants (62.5%). Total insulin dosage decreased from 138 ± 35 IU at baseline to 126 ± 42 IU after OI (p = 0.04) and 127 ± 42 IU after follow-up (p = 0.05). HbA1 c was lower after OI (-0.3 ± 0.1%; p = 0.01) in all participants. Participants in Group B tended to have greater reductions in insulin (Δ-19 IU vs. Δ-4 IU; p = 0.42) and weight loss (Δ-2.8 kg vs. Δ-0.2 kg; p = 0.65) after follow-up. Severe hypoglycemia was not observed. EQ-5 D increase not significantly after follow-up (57.2 ± 24.0% vs. 64.7 ± 21.5%; p = 0.21). Conclusions: The feasibility and practicability of OI in outpatients were demonstrated. OI frequency appears to correlate with insulin reduction and weight loss. Proper insulin dose adaptation during OI is necessary. Presumably, repeated OIs are required for substantial beneficial metabolic effects.

An encompassing review of meta-analyses and systematic reviews of the effect of oats on all-cause mortality, cardiovascular risk, diabetes risk, body weight/adiposity and gut health

The ability of oats to reduce blood cholesterol is well established but there is increasing evidence that its health benefits extend well beyond that. The purpose of this review was to critically evaluate the state of the science of oats in relation to all-cause mortality, cardiovascular and diabetes risk and the effects of oats on blood lipids, blood glucose, blood pressure, weight management and gut health from meta-analyses and systematic reviews. Limited epidemiological data indicated a possible beneficial effect of oats on all-cause mortality and incident diabetes when high versus low oat consumers were compared, but its effect on cardiovascular events was not adequately discerned. Observational data also showed an inverse association between oat intake and blood cholesterol, blood pressure, body weight and obesity variables in different populations. Randomized controlled oat intervention studies demonstrated a significant reduction in postprandial blood glucose in both diabetic and non-diabetic subjects, fasting blood glucose in diabetic subjects, blood pressure in prehypertensive individuals, and body weight and adiposity in overweight individuals. Increased fecal bulk was observed but clinical data for a potential gut barrier effect is lacking. The mechanism of action of each health effect was reviewed. While beta-glucan viscosity was once considered the only mode of action, it is evident that the fermentation products of beta-glucan and the associated gut microbial changes, as well as other components in oats (i.e., avenanthramides etc.) also play an important role.

Effect of special types of bread with select herbal components on postprandial glucose levels in diabetic patients

BACKGROUND

Nutrition recommendations in patients with type 2 diabetes mellitus (T2DM) are to consume rye or integral bread instead of white bread. A positive effect on glucoregulation has been achieved by enriching food with various biologically active substances of herbal origin, so we formulated an herbal mixture that can be used as a supplement for a special type of bread (STB) to achieve better effects on postprandial glucose and insulin levels in patients with T2DM.

AIM

To compare organoleptic characteristics and effects of two types of bread on postprandial glucose and insulin levels in T2DM patients.

METHODS

This trial included 97 patients with T2DM. A parallel group of 16 healthy subjects was also investigated. All participants were given 50 g of rye bread and the same amount of a STB with an herbal mixture on 2 consecutive days. Postprandial blood glucose and insulin levels were compared at the 30th, 60th, 90th and 120th min. A questionnaire was used for subjective estimation of the organoleptic and satiety features of the two types of bread.

RESULTS

Compared to patients who consumed rye bread, significantly lower postprandial blood glucose and insulin concentrations were found in T2DM patients who consumed STB. No relevant differences were found among the healthy subjects. Subjectively estimated organoleptic and satiety characteristics are better for STB than for rye bread.

CONCLUSION

STB have better effects than rye bread on postprandial glucoregulation in T2DM patients. Subjectively estimated organoleptic and satiety characteristics are better for STB than for rye bread. Therefore, STB can be recommended for nutrition in T2DM patients.

Is breakfast consumption detrimental, unnecessary, or an opportunity for health promotion? A review of cardiometabolic outcomes and functional food choices

Breakfast consumption is generally considered a health-promoting habit for cardiometabolism, particularly with regard to chrononutrition. Glucose uptake is enhanced by proper insulin secretion triggered by the pancreatic clock, averting metabolic dysregulation related to insulin resistance. Breakfast skipping, in turn, is often considered a behaviour detrimental to health, in part due to putative inverse metabolic actions compared to breakfast consumption, such that breakfast skipping may promote circadian desynchrony. However, most ill health concerns about breakfast skipping are inferred from observational research, and recent well-controlled randomized clinical trials have shown benefits of breakfast skipping for cardiovascular risk factors. Accordingly, this review describes the effects of breakfast consumption versus breakfast skipping on cardiovascular risk factors (blood pressure and glycaemic and lipid indices). In addition, the view of breakfast consumption as an opportunity for functional food ingestion is considered to provide further insights into decision-making practice. Collectively, both breakfast consumption and breakfast skipping can be considered viable habits, but they depend on individual preferences, planning, and the specific foods being consumed or omitted. When consumed, breakfast should consist primarily of functional foods typical for this meal (e.g., eggs, dairy products, nuts, fruits, whole grains, coffee, tea, etc.). While breakfast consumption aligns with chrononutrition principles, breakfast skipping can contribute to a calorie deficit over time, which has the potential for widespread cardiometabolic benefits for patients with overweight/obesity. The concepts and practical considerations discussed in the present review may aid health care personnel in personalising breakfast consumption recommendations for diverse patient populations.

Effect of viscous soluble dietary fiber on glucose and lipid metabolism in patients with type 2 diabetes mellitus: a systematic review and meta-analysis on randomized clinical trials

Background

The effect of viscous soluble dietary fiber on glucose and lipid metabolism in type 2 diabetes mellitus (T2DM) remains controversial, and the dose-response relationship of its effect on blood glucose and blood lipid level is still unclear.

Methods

We conducted comprehensive searches in several databases up to 17 January 2023. We conducted a dose-response analysis of randomized controlled trials (RCTs) to investigate the effect of viscous dietary fiber on glucose and lipid metabolism in patients with T2DM.

Results

Statistical significance was observed in the decreases of glycosylated hemoglobin (HbA1c) (mean difference) [MD = -0.47; 95%CI: (-0.66, -0.27)], fasting blood glucose (FBG) [MD = -0.93; 95%CI: (-1.46, -0.41)], total cholesterol (TC) [MD = -0.33; 95%CI: (-0.46, -0.21)], and low-density lipoprotein and cholesterol (LDL-C) [MD = -0.24; 95%CI: (-0.35, -0.13)]. Contrarily, no difference was observed regarding the level of high-density lipoprotein cholesterol (HDL-C) or triglyceride (TG). In addition, the effect on fasting insulin remains unclear. Results from the subgroup analyses showed that an intervention duration longer than 6 weeks had a significant effect on the HbA1c level; a treatment dosage higher than 8.3 g/day had a significant effect on the FBG level.

Conclusions

Supplementation of viscous dietary fiber is beneficial to control blood glucose and blood lipid in T2DM.

Development of a Functional Acceptable Diabetic and Plant-Based Snack Bar Using Mushroom (Coprinus comatus) Powder

Consumers' growing concern about health and well-being has led to increased interest in functional foods. This research aims to evaluate the physicochemical and antioxidant properties of a functional plant-based (PB) snack bar enriched with Coprinus comatus powder. The snack bar formulations exhibited a wide range of flavor and textural characteristics. Two PB snack bars and four commercial bars were evaluated by a consumer panel of healthy volunteers (n = 20). The PB snack bar scored 'like extremely' on the 9-point hedonic scale. External preference mapping determined that sweetness, flavors, cohesiveness, gumminess, and adhesion had the greatest influence on consumer acceptability. Water content, ash, protein, fat, carbohydrate, reducing sugar, resistant starch, and dietary fiber were measured. Nutritional content was enhanced (omega 3, fiber and protein), and samples were shelf life stable (aw < 0.29; moisture content < 10%). In addition, the PB snack bar underwent simulated digestion according to the INFOGEST protocol, and from the comparative evaluation, the PB snack can be seen to control the post-prandial glycemic responses, as observed by the different degree of reducing sugars released via the matrix. The PB snack bar can be further functionally enhanced by the addition of their unique ingredients such as Coprinus comatus. Coprinus comatus powder is claimed to benefit glycemic control in diabetes and has attracted growing interest in terms of its potential use in natural products with possible health benefits.

The Development of Nonalcoholic Fatty Liver Disease and Metabolic Syndromes in Diet-Induced Rodent Models

Dietary macronutrients are essential for metabolic regulation and insulin function. The present study examined the effects of different high-fat diets (HFDs) and high-carbohydrate diets (HCDs) on the development of non-alcoholic fatty liver disease and metabolic syndrome indices in healthy adult male Wistar albino rats. Forty-two rats were distributed into six groups (n = 7), which were fed the following for 22 weeks: (1) a control diet; (2) a high-carbohydrate, low-fat diet (HCD-LFD); (3) high-saturated-fat, low-carbohydrate diet (HSF-LCD); (4) a high-monounsaturated-fat diet (HMUSF); (5) a high medium-chain fat diet (HMCF); and a (6) a high-carbohydrate, high-fiber diet (HCHF). In comparison to the control, the body weight increased in all the groups. The HSF-LCD group showed the highest levels of cholesterol, triglyceride, low-density lipoprotein, hepatic enzyme, insulin resistance, and Homeostatic Model Assessment for Insulin Resistance. A liver histology analysis of the HSF-LCD group showed macrovesicular hepatic steatosis associated with large hepatic vacuolation. Additionally, it showed marked periportal fibrosis, especially around the blood vessels and blood capillaries. The lowest levels of fasting glycemia, insulin, and HOMA-IR were observed in the HCHF group. In conclusion, these findings show that dietary saturated fat and cholesterol are principal components in the development and progression of non-alcoholic fatty liver disease in rats, while fiber showed the greatest improvement in glycemic control.

Efficacy of multigrain supplementation in type 2 diabetes mellitus: A pilot study protocol for a randomized intervention trial

BACKGROUND

Uncontrolled type 2 diabetes mellitus (T2DM) may lead to microvascular complications (nephropathy, retinopathy, and neuropathy) and cardiovascular diseases. The beta-glucan content in grains has the potential to improve insulin sensitivity, lowering postprandial glucose response and reducing inflammation degrees. A proper combination of grains not only satisfies human body’s need, but also provides essential and reasonable nutritional contents. However, no trial has been conducted to evaluate the roles of multigrain in T2DM.

AIM

To determine the efficacy of multigrain supplementation among T2DM patients.

METHODS

From October 2020 to June 2021, a total of 50 adults living with T2DM, who were receiving standard diabetes care at Day Care Clinic, were randomized into either a supplementation group or a control group. The supplementation group received twice daily 30 g multigrain supplement (equivalent to 3.4 g beta-glucan) with standard medication for 12 wk, while the control group was prescribed with standard medication. Parameters such as glycemic control (HbA1c, FPG, and HOMO-IR), cardiometabolic profile (lipid profile, renal function test, and liver function test), oxidative stress status, nutritional status, and quality of life (QoL) were assessed at two time points: Baseline and the end of the treatment period (week 12).

RESULTS

The primary outcomes were the mean difference of glycated haemoglobin (%), fasting plasma glucose, and serum insulin as intervention effects. Secondary outcomes included the measurement of cardiometabolic profile, antioxidative and oxidative stress status, nutritional status indices, and QoL. Tertiary outcomes involved the determination of safety and tolerability, and supplementation compliance.

CONCLUSION

The present clinical trial will reveal the effectiveness of multigrain supplementation among T2DM patients for the improvement of diabetes management.

Mediating effect of BMI on the relation of dietary patterns and glycemic control inT2DM patients: results from China community-based cross-sectional study

OBJECTIVE

To analyze the effects of different dietary types on in type 2 diabetes mellitus (T2DM) and determine the mediating effects of Body Mass Index (BMI) on dietary type with Fasting Plasma Glucose (FPG), Glycosylated Hemoglobin (HbA1c) on the associations in T2DM.

METHODS

Data of community-based cross-sectional study with 9602 participants including 3623 men and 5979 women were collected from the project 'Comprehensive Research in prevention and Control of Diabetes mellitus (CRPCD)' conducted by Jiangsu Center for Disease Control and Prevention in 2018. The dietary data were collected from a food frequency qualitative questionnaire (FFQ) and dietary patterns were derived through Latent Class Analysis (LCA). Then, Logistics regression analyses were used to evaluate the associations of FPG, HbA1c with different dietary patterns. The BMI (BMI = height/weight²) was used as a moderator to estimate the mediating effect. Mediation analysis was performed using hypothetical variables, the mediation variables, to identify and explain the observed mechanism of association between the independent and dependent variables while the moderation effect was tested with multiple regression analysis with interaction terms.

RESULTS

After completing Latent Class Analysis (LCA), the dietary patterns were divided into three categories: TypeI, TypeII, TypeIII. After adjusting for confounding factors such as gender, age, education level, marital status, family income, smoking, drinking, disease course, HDL-C, LDL-C, TC, TG, oral hypoglycemic drugs, insulin therapy, Hypertension, Coronary heart disease, Stroke, Type III were all significantly associated with HbA1c compared to those with Type I (P < 0.05), and the research showed the patients with Type III had High glycemic control rate. Taking type I as the reference level, the 95% Bootstrap confidence intervals of the relative mediating effect of TypeIII on FPG were (-0.039, -0.005), except 0, indicating that the relative mediating effect was significant (α_III = 0.346*, β_IIIFPG = -0.060*). The mediating effect analysis was performed to demonstrate that BMI was used as a moderator to estimate the moderation effect.

CONCLUSIONS

Our findings demonstrate that consuming Type III dietary patterns associates with good glycemic control in T2DM and the BMI associations would be playing a two-way effect between diet and FPG in Chinese population with T2DM, indicated that Type III could not only directly affect FPG, but also affect FPG through the mediating effect of BMI.

Whole grains-derived functional ingredients against hyperglycemia: targeting hepatic glucose metabolism

Type 2 diabetes mellitus (T2DM) is characterized by the dysregulation of glucose homeostasis, resulting in hyperglycemia. However, concerns have been raised about the safety and efficacy of current hypoglycemic drugs due to undesirable side effects. Increasing studies have shown that whole grains (WG) consumption is inversely associated with the risk of T2DM and its subsequent complications. Thus, dietary strategies involving functional components from the WG provide an intriguing approach to restoring and maintaining glucose homeostasis. This review provides a comprehensive understanding of the major functional components derived from WG and their positive effects on glucose homeostasis, demonstrates the underlying molecular mechanisms targeting hepatic glucose metabolism, and discusses the unclear aspects according to the latest viewpoints and current research. Improved glycemic response and insulin resistance were observed after consumption of WG-derived bioactive ingredients, which are involved in the integrated, multi-factorial, multi-targeted regulation of hepatic glucose metabolism. Promotion of glucose uptake, glycolysis, and glycogen synthesis pathways, while inhibition of gluconeogenesis, contributes to amelioration of abnormal hepatic glucose metabolism and insulin resistance by bioactive components. Hence, the development of WG-based functional food ingredients with potent hypoglycemic properties is necessary to manage insulin resistance and T2DM.

The separate effects of whole oats and isolated beta-glucan on lipid profile: A systematic review and meta-analysis of randomized controlled trials

BACKGROUND & AIMS

It is well known that dietary fiber positively impacts the microbiome and health as a whole. However, the health effects of β-glucan, a dietary fiber extracted from oats, have been questioned when administered alone or incorporated into other foods. The purpose of this systematic review and meta-analysis was to evaluate the impact of oats or β-glucan supplements on the lipid profile.

METHODS

Randomized controlled trials with parallel-arm or crossover blinded interventions at least two weeks in duration, for hyperlipidemic or non-hyperlipidemic men and women ≥18 years of age were selected. Only single (participants blinded) or double-blinded studies that compared oat or isolated β-glucan with a placebo/control group were considered for this review. The databases EMBASE, PubMed, Web of science and CINHAL were searched, from the earliest indexed year available online to the end of January 2022. Random-effects models were used to combine the estimated effects extracted from individual studies, and data were summarized as standardized mean difference (SMD) and 95% confidence interval (95%CI).

RESULTS

A total of 811 articles were screened for eligibility, and relevant data were extracted from 28 studies, totaling 1494 subjects. Oat interventions TC (-0.61, 95%CI: -0.84;-0.39, p < 0.00001, and -0.70, 95%CI: -1.07;-0.34, p = 0.0002, respectively) and LDL (-0.51, 95%CI: -0.71;-0.31, p < 0.00001, and -0.38, 95%CI: -0.60;-0.15, p = 0.001, respectively). Moreover, isolated β-glucan interventions from parallel-arm studies decreased TC (-0.73, 95%CI: -1.01;-0.45, p < 0.00001), LDL (-0.58, 95%CI: -0.85;-0.32, p < 0.0001) and triglycerides (-0.30, 95%CI: -0.49;-0.12, p = 0.001). HDL was not altered by either oat or isolated β-glucan (p > 0.05).

CONCLUSION

Overall, this review showed that both oat and isolated β-glucan interventions improved lipid profiles. Furthermore, the ingestion of oats or isolated β-glucan supplements are effective tools to combat dyslipidemia and should be considered in cardiovascular disease prevention.

Chronic consumption of probiotics, oats, and apples has differential effects on postprandial bile acid profile and cardiometabolic disease risk markers compared with an isocaloric control (cornflakes): a randomized trial

BACKGROUND

Dietary components that impact the gut microbiota may beneficially affect cardiometabolic health, possibly by altered bile acid metabolism. However, impacts of these foods on postprandial bile acids, gut microbiota, and cardiometabolic risk markers are unclear.

OBJECTIVES

The aim of this study was to determine the chronic effects of probiotics, oats, and apples on postprandial bile acids, gut microbiota, and cardiometabolic health biomarkers.

METHODS

Using an acute within chronic parallel design, 61 volunteers (mean ± SD: age 52 ± 12 y; BMI 24.8 ± 3.4 kg/m²) were randomly assigned to consume 40 g cornflakes (control), 40 g oats or 2 Renetta Canada apples each with 2 placebo capsules per day or 40 g cornflakes with 2 Lactobacillus reuteri capsules (>5 × 10⁹ CFU) per day, for 8 wk. Fasting and postprandial serum/plasma bile acids and cardiometabolic health biomarkers, fecal bile acids, and gut microbiota composition were determined.

RESULTS

At week 0, oats and apples significantly decreased postprandial serum insulin [area under the curve (AUC): 25.6 (17.4, 33.8) and 23.4 (15.4, 31.4) vs. 42.0 (33.7, 50.2) pmol/L × min and incremental AUC (iAUC): 17.8 (11.6, 24.0) and 13.7 (7.7, 19.8) vs. 29.6 (23.3, 35.8) pmol/L × min] and C-peptide responses [AUC: 599 (514, 684) and 550 (467, 632) vs. 750 (665, 835) ng/mL × min], whereas non-esterified fatty acids were increased [AUC 135 (117, 153) vs. 86.3 (67.9, 105) and iAUC 96.2 (78.8, 114) vs. 60 (42.1, 77.9) mmol/L × min] after the apples vs. control (P ≤ 0.05). Postprandial unconjugated [AUC: predicted means (95% CI) 1469 (1101, 1837) vs. 363 (-28, 754) μmol/L × min and iAUC: 923 (682, 1165) vs. 22.0 (-235, 279) μmol/L × min)] and hydrophobic [iAUC: 1210 (911, 1510) vs. 487 (168, 806) μmol/L × min] bile acid responses were increased after 8 wk probiotic intervention vs. control (P ≤ 0.049). None of the interventions modulated the gut microbiota.

CONCLUSIONS

These results support beneficial effects of apples and oats on postprandial glycemia and the ability of the probiotic Lactobacillus reuteri to modulate postprandial plasma bile acid profiles compared with control (cornflakes), with no relationship evident between circulating bile acids and cardiometabolic health biomarkers.

[Nutrition for diabetic patients (Update 2023)]

All patients with diabetes require individual and personalized nutritional consultation with professionals. The patient's needs should be the primary focus of the dietary therapy, taking their lifestyle and the type of diabetes into consideration. With the recommendations to the patient's diet, there need to be specific metabolic goals to reduce the disease's progression and to avoid long term health effects. Therefore, practical guidelines such as portion size and meal planning tips should be the main focus.According to the latest national and international standards, patients suffering from diabetes should have access to nutrition consulting and nutritional training. During consultation they can be supported on- how to manage their health condition and choosing food and beverage to improve their health.These practical recommendations sum up the latest literature on nutritional aspects of diabetes treatment.

Nordic dietary patterns and cardiometabolic outcomes: a systematic review and meta-analysis of prospective cohort studies and randomised controlled trials

AIMS/HYPOTHESIS

Nordic dietary patterns that are high in healthy traditional Nordic foods may have a role in the prevention and management of diabetes. To inform the update of the EASD clinical practice guidelines for nutrition therapy, we conducted a systematic review and meta-analysis of Nordic dietary patterns and cardiometabolic outcomes.

METHODS

We searched MEDLINE, EMBASE and The Cochrane Library from inception to 9 March 2021. We included prospective cohort studies and RCTs with a follow-up of ≥1 year and ≥3 weeks, respectively. Two independent reviewers extracted relevant data and assessed the risk of bias (Newcastle-Ottawa Scale and Cochrane risk of bias tool). The primary outcome was total CVD incidence in the prospective cohort studies and LDL-cholesterol in the RCTs. Secondary outcomes in the prospective cohort studies were CVD mortality, CHD incidence and mortality, stroke incidence and mortality, and type 2 diabetes incidence; in the RCTs, secondary outcomes were other established lipid targets (non-HDL-cholesterol, apolipoprotein B, HDL-cholesterol, triglycerides), markers of glycaemic control (HbA1c, fasting glucose, fasting insulin), adiposity (body weight, BMI, waist circumference) and inflammation (C-reactive protein), and blood pressure (systolic and diastolic blood pressure). The Grading of Recommendations, Assessment, Development and Evaluation (GRADE) approach was used to assess the certainty of the evidence.

RESULTS

We included 15 unique prospective cohort studies (n=1,057,176, with 41,708 cardiovascular events and 13,121 diabetes cases) of people with diabetes for the assessment of cardiovascular outcomes or people without diabetes for the assessment of diabetes incidence, and six RCTs (n=717) in people with one or more risk factor for diabetes. In the prospective cohort studies, higher adherence to Nordic dietary patterns was associated with 'small important' reductions in the primary outcome, total CVD incidence (RR for highest vs lowest adherence: 0.93 [95% CI 0.88, 0.99], p=0.01; substantial heterogeneity: I2=88%, pQ<0.001), and similar or greater reductions in the secondary outcomes of CVD mortality and incidence of CHD, stroke and type 2 diabetes (p<0.05). Inverse dose-response gradients were seen for total CVD incidence, CVD mortality and incidence of CHD, stroke and type 2 diabetes (p<0.05). No studies assessed CHD or stroke mortality. In the RCTs, there were small important reductions in LDL-cholesterol (mean difference [MD] -0.26 mmol/l [95% CI -0.52, -0.00], pMD=0.05; substantial heterogeneity: I2=89%, pQ<0.01), and 'small important' or greater reductions in the secondary outcomes of non-HDL-cholesterol, apolipoprotein B, insulin, body weight, BMI and systolic blood pressure (p<0.05). For the other outcomes there were 'trivial' reductions or no effect. The certainty of the evidence was low for total CVD incidence and LDL-cholesterol; moderate to high for CVD mortality, established lipid targets, adiposity markers, glycaemic control, blood pressure and inflammation; and low for all other outcomes, with evidence being downgraded mainly because of imprecision and inconsistency.

CONCLUSIONS/INTERPRETATION

Adherence to Nordic dietary patterns is associated with generally small important reductions in the risk of major CVD outcomes and diabetes, which are supported by similar reductions in LDL-cholesterol and other intermediate cardiometabolic risk factors. The available evidence provides a generally good indication of the likely benefits of Nordic dietary patterns in people with or at risk for diabetes.

REGISTRATION

ClinicalTrials.gov NCT04094194.

FUNDING

Diabetes and Nutrition Study Group of the EASD Clinical Practice.

Wholegrain fermentation affects gut microbiota composition, phenolic acid metabolism and pancreatic beta cell function in a rodent model of type 2 diabetes

The intestinal microbiota plays an important role in host metabolism via production of dietary metabolites. Microbiota imbalances are linked to type 2 diabetes (T2D), but dietary modification of the microbiota may promote glycemic control. Using a rodent model of T2D and an in vitro gut model system, this study investigated whether differences in gut microbiota between control mice and mice fed a high-fat, high-fructose (HFHFr) diet influenced the production of phenolic acid metabolites following fermentation of wholegrain (WW) and control wheat (CW). In addition, the study assessed whether changes in metabolite profiles affected pancreatic beta cell function. Fecal samples from control or HFHFr-fed mice were fermented in vitro with 0.1% (w/v) WW or CW for 0, 6, and 24 h. Microbiota composition was determined by bacterial 16S rRNA sequencing and phenolic acid (PA) profiles by UPLC-MS/MS. Cell viability, apoptosis and insulin release from pancreatic MIN6 beta cells and primary mouse islets were assessed in response to fermentation supernatants and selected PAs. HFHFr mice exhibited an overall dysbiotic microbiota with an increase in abundance of proteobacterial taxa (particularly Oxalobacteraceae) and Lachnospiraceae, and a decrease in Lactobacillus. A trend toward restoration of diversity and compositional reorganization was observed following WW fermentation at 6 h, although after 24 h, the HFHFr microbiota was monodominated by Cupriavidus. In parallel, the PA profile was significantly altered in the HFHFr group compared to controls with decreased levels of 3-OH-benzoic acid, 4-OH-benzoic acid, isoferulic acid and ferulic acid at 6 h of WW fermentation. In pancreatic beta cells, exposure to pre-fermentation supernatants led to inhibition of insulin release, which was reversed over fermentation time. We conclude that HFHFr mice as a model of T2D are characterized by a dysbiotic microbiota, which is modulated by the in vitro fermentation of WW. The differences in microbiota composition have implications for PA profile dynamics and for the secretory capacity of pancreatic beta cells.

Effect of oats and oat ß-glucan on glycemic control in diabetes: a systematic review and meta-analysis of randomized controlled trials

Introduction

Current health claims recognize the ability of oat ß-glucan to lower blood cholesterol; however, its ability to improve glycemic control is less certain. We undertook a systematic review and meta-analysis of randomized controlled trials (RCTs) to update the evidence on the effect of oats and oat ß-glucan on glycemic control in individuals with diabetes.

Research design and methods

MEDLINE, EMBASE and Cochrane were searched (June 2021) for RCTs of ≥2 weeks investigating the effect of oat ß-glucan on glycemic control in diabetes. The outcomes were hemoglobin A1c (HbA1c), fasting glucose, 2-hour postprandial glucose (2h-PG) from a 75 g oral glucose tolerance test, homeostatic model assessment of insulin resistance (HOMA-IR) and fasting insulin. Independent reviewers extracted the data and assessed the risk of bias. Data were pooled using the generic inverse variance method. Heterogeneity was assessed (Cochran Q) and quantified (I2). Pooled estimates were expressed as mean difference (MD) with 95% CI. The certainty of evidence was assessed using the Grading of Recommendations, Assessment, Development and Evaluations approach.

Results

Eight trial comparisons (n=407) met the eligibility criteria. All trials were in adults with type 2 diabetes who were predominantly middle-aged, overweight and treated by antihyperglycemic medications or insulin. A median dose of 3.25 g of oat ß-glucan for a median duration of 4.5 weeks improved HbA1c (MD, −0.47% (95% CI −0.80 to −0.13), pMD=0.006), fasting glucose (−0.75 mmol/L (−1.20 to –0.31), pMD<0.001), 2h-PG (−0.42 mmol/L (−0.70 to –0.14), pMD=0.003) and HOMA-IR (−0.88 (−1.55 to –0.20), pMD=0.011). There was a non-significant reduction in fasting insulin (−4.30 pmol/L (−11.96 to 3.35), pMD=0.271). The certainty of evidence was high for fasting glucose, moderate for HOMA-IR and fasting insulin (downgraded for imprecision), and low for HbA1c and 2h-PG (downgraded for imprecision and inconsistency).

Conclusions

Consumption of oats and oat ß-glucan results in generally small improvements in established markers of fasting and postprandial glycemic control beyond concurrent therapy in adults with type 2 diabetes. The current evidence provides a very good indication for reductions in fasting glucose and less of an indication for reductions in HbA1c, 2h-PG, fasting insulin and HOMA-IR in this population.

Trial registration number

NCT04631913.

The inhibition of intestinal glucose absorption by oat-derived avenanthramides

Avenanthramides are phenolic compounds unique to oats and may contribute to health-promoting properties associated with oat consumption. This study used Xenopus laevis oocytes expressing the glucose transporters, glucose transporter 2 (GLUT2) or sodium-glucose transport protein 1 (SGLT1) and human Caco-2 cells models to investigate the effect of oat avenanthramides on human intestinal glucose transporters. The presence of avenanthramide reduced the glucose uptake in a dose-dependent manner in Caco-2 cells. Glucose uptake in oocytes expressing either GLUT2 or SGLT1 was nullified by oat avenanthramide. There was no significant difference between the inhibition potencies of avenanthramides C and B. Thus, our results suggest that avenanthramides may contribute to the antidiabetic properties of oats. PRACTICAL APPLICATIONS: The present research focus on the antidiabetic properties of avenanthramides, which are unique phenolic compounds found in oats. Inhibiting the activities of the glucose transport proteins expressed in the small intestine is a known strategy to improve the control of postprandial glucose level. We therefore examined the inhibitory effects of avenanthramides on two glucose transporters, glucose transporter 2 and sodium-glucose transport protein 1, predominantly found in the small intestine using the human small intestinal cell model Caco-2 cell line and by heterologously expressing these two transporters in the Xenopus laevis oocytes. Based on our results, we have confirmed for the first time that the glucose uptake is indeed inhibited by the presence of avenanthramides, suggesting the possibility of incorporating avenanthramides in foods to enhance postprandial glucose response, and ultimately improve the management of diabetes. Therefore, future research could consider utilizing this evidence in the development of diabetic-friendly functional foods or nutraceuticals containing avenanthramides.

Ameliorative and Antioxidative Potential of Lactobacillus plantarum-Fermented Oat (Avena sativa) and Fermented Oat Supplemented with Sidr Honey against Streptozotocin-Induced Type 2 Diabetes in Rats

The ameliorative and antioxidative stress effects of probiotic-enriched fermented oat (FOE) or fermented oat with honey (HFOE) extracts on streptozotocin-induced diabetes in rats were examined. The total phenolic content (TPC) and antioxidant activity (AOA) were increased in FOE and HFOE after 72 h of fermentation, and γ-aminobutyric acid (GABA) reached 7.35 mg 100 g-1 in FOE and 8.49 mg 100 g-1 in HFOE. The β-glucan levels were slightly decreased to 2.45 g 100 g-1 DW in FOE and 2.63 g 100 g-1 DW in HFOE. The antidiabetic and hypolipidemic properties of FOE and HFOE were studied in a designed animal model with seven treated groups for 6 weeks. Groups were treated as follows: group 1 (negative group, NR) and group 2 (diabetic rats, DR) were administered 7 mL distilled water orally per day; group 3 (DR + MET) rats were orally administered 50 mg standard drug Metformin kg-1 daily; group 4 (DR + FOE1) diabetic rats were orally administered 3.5 mL FOE daily; group 5 (DR + FOE2) rats were orally administered 7 mL FOE daily; group 6 (DR + HFOE1) rats were orally administered 3.5 mL HFOE daily; and group 7 (DR + HFOE2) rats were orally administered 7 mL HFOE daily. The HFOE at the high dose had a synergistic effect, lowering random blood glucose (RBG) and fasting blood glucose (FBG). The hypolipidemic potential of HFOE at the high dose was indicated by significant reductions in triglycerides (TG), total cholesterol (CHO), high- and low-density lipoproteins (HDL and LDL), and very-low-density lipoproteins (VLDL). In addition, 7 mL of HFOE improved liver and kidney function more effectively than other fermented extracts or Metformin. As well as the antioxidant enzyme activity, reduced glutathione (GSH), catalase (CAT), superoxide dismutase (SOD), and malonaldehyde (MDA) were significantly enhanced after the administration of HFOE at 7 mL by 68.6%, 71.5%, 55.69%, and 15.98%, respectively, compared to the DR group. In conclusion, administration of L. plantarum-fermented oats supplemented with honey demonstrated antidiabetic effects and a potential approach for controlling glucose levels and lipid profiles, and protecting against oxidative stress.

The Impact of Cereal Grain Composition on the Health and Disease Outcomes

Whole grains are a pivotal food category for the human diet and represent an invaluable source of carbohydrates, proteins, fibers, phytocompunds, minerals, and vitamins. Many studies have shown that the consumption of whole grains is linked to a reduced risk of cancer, cardiovascular diseases, and type 2 diabetes and other chronic diseases. However, several of their positive health effects seem to disappear when grains are consumed in the refined form. Herein we review the available literature on whole grains with a focus on molecular composition and health benefits on many chronic diseases with the aim to offer an updated and pragmatic reference for physicians and nutrition professionals.

Genotypic and environmental variations in phenolic acid and avenanthramide content of Canadian oat (Avena sativa)

Phenolic compounds (PC) in oat may possess health promoting properties. This study evaluated the effect of genotype, environment, and their interaction on the phenolic acid and avenanthramide (AVN) concentration in Canadian oat. Six cultivars were grown at eight locations across Canada in a randomised complete block design with three field replicates. Free PCs were extracted from oat groat flour and analysed using a UPLC-PDA system. The cumulative concentration of free PCs and AVN ranged from 58 to 350 and 9 to 244 µg/g, respectively. The effect of environment was significant (p < 0.0001) for the concentration of all PCs. Cultivar differences significantly influenced the concentration of all PCs but AVNs A and B. The growing location explained > 68% of the variation in the concentration of AVN. Thus understanding the genotypic and environmental triggers of individual PCs may help agronomists and breeders strategize in selecting and growing oat cultivars of interest.

Multifunctional Eco-Friendly Synthesis of ZnO Nanoparticles in Biomedical Applications

This work describes an environmental-friendly preparation of ZnO nanoparticles using aqueous oat extract. The advanced electrochemical and optical features of green synthesized ZnONPs displayed excellent antibacterial activity and exhibited an important role in pharmaceutical determinations. The formation of nanoscale ZnO was confirmed using various spectroscopic and microscopic investigations. The formed nanoparticles were found to be around 100 nm. The as-prepared ZnONPs were monitored for their antibacterial potential against different bacterial strains. The inhibition zones for ZnONPs were found as Escherichia coli (16 mm), Pseudomonas aeruginosa (17 mm), Staphylococcus aureus (12 mm) and Bacillus subtilis (11 mm) using a 30-µg mL-1 sample concentration. In addition, ZnONPs exhibited significant antioxidant effects, from 58 to 67%, with an average IC50 value of 0.88 ± 0.03 scavenging activity and from 53 to 71% (IC50 value of 0.73 ± 0.05) versus the scavenging free radicals DPPH and ABTS, respectively. The photocatalytic potential of ZnONPs for Rhodamine B dye degradation under UV irradiation was calculated. The photodegradation process was carried out as a function of time-dependent and complete degradation (nearly 98%), with color removal after 120 min. Conclusively, the synthesized ZnONPs using oat biomass might provide a great promise in the future for biomedical applications.

Recent advances of cereal β-glucan on immunity with gut microbiota regulation functions and its intelligent gelling application

β-glucan from cereals such as wheat, barley, oats and rye are a water-soluble dietary fiber, which are composed of repeating (1→4)-β-bond β-D-glucopyranosyl units and a single (1→3)-β-D-bond separated unit. β-glucan has a series of physicochemical properties (such as viscosity, gelling properties, solubility, etc.), which can be used as a food gel and fat substitute. Its structure endows the healthy functions, including anti-oxidative stress, lowering blood glucose and serum cholesterol, regulating metabolic syndrome and exerting gut immunity via gut microbiota. Due to their unique structural properties and efficacy, cereal β-glucan are not only applied in food substrates in the food industry, but also in food coatings and packaging. This article reviewed the applications of cereal β-glucan in hydrogels, aerogels, intelligent packaging systems and targeted delivery carriers in recent years. Cereal β-glucan in edible film and gel packaging applications are becoming more diversified and intelligent in recent years. Those advances provide a potential solution based on cereal β-glucan as biodegradable substances for immune regulation delivery system and intelligent gelling material in the biomedicine field.

Fortifying a meal with oyster mushroom powder beneficially affects postprandial glucagon-like peptide-1, non-esterified free fatty acids and hunger sensation in adults with impaired glucose tolerance: a double-blind randomized controlled crossover trial

Purpose

Impaired glucose tolerance (IGT) is a pathophysiological condition characterized by insulin resistance with known metabolic consequences such as postprandial hyperglycemia and hypertriglyceridemia. We hypothesized that fortifying a meal with mushrooms rich in β-glucans may diminish glucose and triglyceride responses by improving postprandial gastrointestinal hormone release.

Methods

In a randomized controlled crossover study, 22 subjects with IGT ingested a meal either enriched with 20 g powder (8.1 g β-glucans) of oven-dried Pleurotus ostreatus (enriched meal, EN) or without enrichment (control meal, CON). Blood was collected before and repeatedly within 4 h after the meal to determine AUC of glucose (primary outcome), insulin, triglycerides, non-esterified free fatty acids (NEFAs), glucagon-like peptide-1 (GLP-1), gastric inhibitory polypeptide (GIP) and ghrelin. Appetite sensations (hunger, satiety, fullness, and desire to eat) were assessed before and after meal consumption by visual analog scales.

Results

Postprandial glucose, insulin, triglycerides, GIP and ghrelin concentrations as well as the corresponding AUCs did not differ between EN and CON. NEFAs-AUC was 14% lower (P = 0.026) and GLP-1-AUC 17% higher (P = 0.001) after EN compared to CON. Appetite ratings did not differ between treatments, except for hunger (AUC 22% lower after EN vs. CON; P = 0.031).

Conclusion

The observed immediate postprandial metabolic changes indicate that an easily manageable fortification of a single meal with powder from dried oyster mushrooms as β-glucan source may improve postprandial metabolism. If the effect is preserved long term, this measure can diminish the risk for further development of overweight/obesity and type 2 diabetes in subjects with IGT.

Clinical trial registration

German Clinical Trial Register on 09/08/2018; trial-ID: DRKS00015244.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00394-021-02674-1.

Application of metabolomics for revealing the interventional effects of functional foods on metabolic diseases

Metabolomics is an important branch of systems biology, which can detect changes in the body's metabolism before and after the intervention of functional foods, identify effective metabolites, and predict the interventional effects and the mechanism. This review summarizes the latest research outcomes regarding interventional effects of functional foods on metabolic diseases via metabolomics analysis. Since metabolomics approaches are powerful strategies for revealing the changes in bioactive compounds of functional foods during processing and storage, we also discussed the effects of these parameters on functional food metabolites using metabolomics approaches. To date, a number of endogenous metabolites related to the metabolic diseases after functional foods intervention have been discovered. Unfortunately, the mechanisms of metabolic disease-related molecules are still unclear and require further studies. The combination of metabolomics with other omics technologies could further promote its ability to fully understand the precise biological processes of functional food intervention on metabolic diseases.

Oat Intake and Risk of Type 2 Diabetes, Cardiovascular Disease and All-Cause Mortality: A Systematic Review and Meta-Analysis

Cardiovascular disease (CVD) and type 2 diabetes (T2D) remain the top disease and mortality burdens worldwide. Oats have been shown to benefit cardiovascular health and improve insulin resistance. However, the evidence linking oat consumption with CVD, T2D and all-cause mortality remains inconclusive. We conducted a comprehensive systematic review and meta-analysis of prospective cohort studies to evaluate the associations between oat consumption and risks of T2D, CVD and all-cause mortality in the general population. Five electronic databases were searched until September, 2020. Study specific relative risks (RR) were meta-analyzed using random effect models. Of 4686 relevant references, we included 9 articles, based on 8 unique studies and 471,157 participants. Comparing oat consumers versus non-consumers, RRs were 0.86 (95% CI 0.72–1.03) for T2D incidence and 0.73 (95% CI 0.5–1.07) for combined CVD incidence. Comparing participants with highest versus lowest oat intake, RRs were 0.78 (95% CI 0.74–0.82) for T2D incidence, 0.81 (95% CI 0.61–1.08) for CHD incidence and 0.79 (95% CI 0.59–1.07) for stroke. For all-cause mortality one study based on three cohorts found RR for men and women were 0.76 (95% CI 0.69–0.85) and 0.78 (95% CI 0.70–0.87), respectively. Most studies (n = 6) were of fair to good quality. This meta-analysis suggests that consumption of oat could reduce the risk for T2D and all-cause mortality, while no significant association was found for CVD. Future studies should address a lack of standardized methods in assessing overall oat intake and type of oat products, and investigate a dose-dependent response of oat products on cardiometabolic outcomes in order to introduce oat as preventive and treatment options for the public.

Do Bioactive Food Compound with Avena sativa L., Linum usitatissimum L. and Glycine max L. Supplementation with Moringa oleifera Lam. Have a Role against Nutritional Disorders? An Overview of the In Vitro and In Vivo Evidence

Functional clinical nutrition is an integrative science; it uses dietary strategies, functional foods and medicinal plants, as well as combinations thereof. Both functional foods and medicinal plants, whether associated or not, form nutraceuticals, which can bring benefits to health, in addition to being included in the prevention and treatment of diseases. Some functional food effects from Avena sativa L. (oats), Linum usitatissimum L. (brown flaxseed), Glycine max L. (soya) and Moringa oleifera have been proposed for nutritional disorders through in vitro and in vivo tests. A formulation called a bioactive food compound (BFC) showed efficiency in the association of oats, flaxseed and soy for dyslipidemia and obesity. In this review, we discuss the effects of BFC in other nutritional disorders, as well as the beneficial effects of M. oleifera in obesity, cardiovascular disease, diabetes mellitus type 2, metabolic syndrome, intestinal inflammatory diseases/colorectal carcinogenesis and malnutrition. In addition, we hypothesized that a BFC enriched with M. oleifera could present a synergistic effect and play a potential benefit in nutritional disorders. The traditional consumption of M. oleifera preparations can allow associations with other formulations, such as BFC. These nutraceutical formulations can be easily accepted and can be used in sweet preparations (fruit and/or vegetable juices, fruit and/or vegetable vitamins, porridges, yogurt, cream, mousses or fruit salads, cakes and cookies) or savory (vegetable purees, soups, broths and various sauces), cooked or not. These formulations can be low-cost and easy-to-use. The association of bioactive food substances in dietary formulations can facilitate adherence to consumption and, thus, contribute to the planning of future nutritional interventions for the prevention and adjuvant treatment of the clinical conditions presented in this study. This can be extended to the general population. However, an investigation through clinical studies is needed to prove applicability in humans.

Potential Health Risk Associated with Mycotoxins in Oat Grains Consumed in Spain

Spain is a relevant producer of oats (Avena sativa), but to date there has been no study on the occurrence/co-occurrence of mycotoxins in oats marketed in Spain. The present study is addressed to overcome this lack of knowledge. One hundred oat kernel samples were acquired across different Spanish geographic regions during the years 2015-2019 and analyzed for mycotoxin content using an ultra-high performance liquid chromatography electrospray ionization tandem mass spectrometry (UPLC-ESI-MS/MS) method and matrix-matched calibration. The focus was on the regulated mycotoxins although other relevant mycotoxins were considered. The percentage of incidence (levels ≥ limit of detection), mean and range (ng/g) of mycotoxins were as follows: zearalenone (66%, mean 39.1, range 28.1-153), HT-2 toxin (47%, mean 37.1, range 4.98-439), deoxynivalenol, (34%, mean 81.4, range 19.1-736), fumonisin B1 (29%, mean 157.5, range 63.2-217.4), and T-2 toxin, (24%, mean 49.9, range 12.3-321). Fumonisin B2, 3-acetyldeoxynivalenol, aflatoxins B1, B2, and G2, and ochratoxin A were also detected at low levels, but aflatoxin G1 was not. The maximum limits established by the European Commission for unprocessed oats were not exceeded, except for zearalenone (in one sample), and the sum of aflatoxins (in two samples). Mycotoxin co-occurrence at quantifiable levels in the same sample (two to five combinations) was found in 31% of samples. The most common mixtures were those of HT-2 + T-2 toxins alone or together with deoxynivalenol and/or zearalenone.

Polyphenols and avenanthramides extracted from oat (Avena sativa L.) grains and sprouts modulate genes involved in glucose and lipid metabolisms in 3T3 L1 adipocytes

This study aimed to evaluate the effect of polyphenol (PE) and avenanthramide (AE) extracts from oat grains (OG) and sprouts (OS) on genes related to glucose and lipid metabolisms in 3T3 L1 adipocytes. The AE-OS exerted the greatest effect on genes involved in glucose metabolism, increasing Glut4, Irs1, and Pi3k expression by 3.0- to 3.9-fold. Conversely, the PE-OS exerted the greatest effect on genes involved in lipid metabolism, decreasing Fasn and Acaca expression by 0.2- to 0.3-fold, and increasing Cpt1a and Acadm expression by 2.7- to 3.0-fold. These effects were mainly related to their high content of avenanthramides A (2p), B (2f), and C (2c), quercetin 3-O-rutinoside, kaempferol, sinapoylquinic acid, and apigenin and luteolin derivatives according to the chemometric analysis. In conclusion, this study demonstrated that oat sprouts extract exerts a greater effect than oat grains on the regulation of genes involved in glucose and lipid metabolisms in adipocytes. PRACTICAL APPLICATIONS: This study demonstrates that polyphenols and avenanthramides extracted from oat (Avena sativa L.) grains and sprouts modulate key genes involved in glucose and lipid metabolisms in adipocytes and that oat sprouts exert a greatest health beneficial effect than oat grains due to their higher content of bioactive compounds. In addition, the chemometric analysis identified the bioactive compounds that can be associated with the beneficial effects of oat grains and sprouts, which can be further used for the identification of oat varieties and oat-derived products with high content of these bioactive compounds and, thus, with high nutraceutical potential.

Global review of heart health claims for oat beta-glucan products

Coronary heart disease (CHD) is the leading cause of death globally. Consumption of whole grains and cereal fiber, as part of a healthy diet, can lower the risk of CHD. Health claims on food products are effective in helping consumers select healthful diets. The US Food and Drug Administration was the first to approve a health claim, in 1997, between beta-glucan soluble fiber from whole oats, oat bran, and whole oat flour and reduced risk of CHD. Only a few countries have approved similar claims. Since 1997, a significant amount of additional evidence has been published on the relationship between oat beta-glucan and CHD. To assist other jurisdictions in potentially utilizing this claim, the full extent of data that supports this claim (ie, the evidence utilized by the US Food and Drug Administration to substantiate the claim, as well as the results of 49 clinical trials published since 1997) are reviewed here. The complexities involved in authoring evidence-based health claims, including the impact of processing on beta-glucan cholesterol-lowering efficacy in approving eligible beta-glucan products, are also discussed.

Incorporation of oat flour into wheat flour noodle and evaluation of its physical, chemical and sensory attributes

Abstract Noodles are popular food and fortified noodles with vital nutrients may build a healthy food habit among people. Oat is a cereal with high nutritional value. Therefore, the current research was undertaken to increase the nutrient content of noodles using oat flour and to evaluate the effects of oat flour on the physicochemical properties and sensory attributes of the noodles. The noodles were prepared following five different formulations (oats: wheat flour in the ratio of 0:100, 20:80, 25:75, 30:70 and 35:65). Other ingredients like table salt, carboxymethyl cellulose (CMC), corn starch, and water were equal in each formulation. To evaluate the best formulation, proximate analysis, functional characteristics and sensory assay were conducted on samples. The formulation having 70% of wheat flour and 30% of oat flour showed the best performance in proximate analysis and sensory evaluation. This formulation of noodles has 13.03% of protein, 1.51% of fat, 1.46% of total ash, 0.76% of fibre, 73.87% of carbohydrate, 361.19 kcal of energy and also a good amount of important minerals. The formulation regarding wheat flour 70% and oat flour 30% may be suggested to the large population who are habituated to consume noodles regularly as the main diet.

The effect of beta-glucan supplementation on glycemic control and variability in adolescents with type 1 diabetes mellitus

AIMS

This study aimed to investigate whether supplemental soluble fiber, oat β-glucan, has any effect on glycemic control and variability of adolescents with type 1 diabetes mellitus.

METHODS

This study was conducted in 30 adolescents with type 1 diabetes mellitus and it consisted of three phases lasting one week. At Phase I, all subjects followed a standard diet program. For Phase II and Phase III, the subjects continued their standard diet program and added natural oat flakes containing 3 g/day and 6 g/day β-glucan, respectively. Glucose levels were monitored by continuous glucose monitoring (CGM). The maximal, minimal, mean and daytime and night blood glucose levels, percentages of glucose values in a target range and below and above a target values were calculated for each of the phases. Premeal, postmeal, peak blood glucose values and peak times of meals were evaluated for each of the phases. Glycemic variability was measured via SD, CV, MAGE, IQR, MODD, LBGI, HBGI, and CONGA parameters.

RESULTS

The maximal, mean and daytime and night blood glucose levels were the lowest at Phase III (p < 0.05). Minimal blood glucose levels were the highest at Phase III (p < 0.05). Phase I, II, and III showed similar durations elapsed for Level 2 and Level 1 hypoglycemia, euglycemia, Level 1 and Level 2 hyperglycemia (p > 0.05). Premeal and postmeal blood glucose levels were lowest at Phase III for breakfast, lunch, and overall (p < 0.05). The lowest peak blood glucose levels were detected at Phase III for breakfast, lunch, dinner and overall (p < 0.05). Phase III also showed delayed peaks for all time-points (p < 0.05 for each) compared to other phases. Phase III had significantly lower levels of SD, CV, LBGI, and CONGA levels than those in either Phase I or Phase II (p < 0.05 for each).

CONCLUSION

6 g/day oat β-glucan have favorable outcomes in glycemic control and variability in adolescents with type 1 diabetes mellitus.

Recent progress in the use of functional foods for older adults: A narrative review

The number and proportion of older adults are increasing globally, and it is predicted that in 2020, there will be 723 million people worldwide aged 66 and older. In recent decades, numerous studies showed that healthy eating is positively associated with better nutritional status and quality of life, and the decreased incidence of noncommunicable diseases. As older adults become health conscious, the demand for foods and beverages rich in nutrients and bioactive compounds has increased. The increased demand for healthy food stimulated a recent rapid increase in designing, producing, and marketing functional foods to prevent or correct nutrient deficiencies and to improve the nutritional status of older adults. These functional products contain and/or are enriched with dietary fiber; omega-3 polyunsaturated fatty acids; phytoestrogens; polyphenols; carotenoids such as alpha- and beta-carotene; lutein and zeaxanthin; pre-, pro-, and synbiotics; and plant sterols and stanols. A limited number of publications have thoroughly addressed the effect of functional foods on the nutritional status of older adults. The goal of this review was to review existing recent research on the role of functional foods in healthy and active aging.

Bile Acids in Patients with Uncontrolled Type 2 Diabetes Mellitus - The Effect of Two Days of Oatmeal Treatment

BACKGROUND

Beta-glucans are effective in binding bile acids (BA) thereby lowering cholesterol concentration. This might contribute to the beneficial effects of the consumption of β-glucan-rich foods like oatmeal on glucose homeostasis.

OBJECTIVE

We measured BA serum concentrations in patients with uncontrolled type 2 diabetes (T2DM) to investigate the effect of two days of oatmeal treatment on BA concentration as compared to a conventional T2DM-adapted diet.

METHODS

The OatMeal And Insulin Resistance study was performed as a randomized, open label crossover dietary intervention study with consecutive inclusion of 15 patients in an inpatient clinical setting. Bile acids were measured by high-resolution mass spectrometry. For statistical analysis, the differences in the concentration of serum BA and laboratory parameters between the fifth day and the third day of each inpatient stay were calculated and the effect compared between both phases by using the Wilcoxon test.

RESULTS

Whereas there was a mean decrease in total BA following oatmeal treatment (-0.82±1.14 µmol/l), there was no decrease following the control treatment. Glycocholic acid was lower after oatmeal treatment but higher following control treatment (-0.09±0.17 vs. 0.05±0.11 µmol/l). The reduction in total BA was directly correlated with a decrease in proinsulin during the oatmeal phase. Decreases in blood lipids or apolipoproteins were mostly greater after oatmeal treatment, but these differences were not statistically significant.

CONCLUSION

Two days of oatmeal diet led to significant reductions in total BA as compared to a diabetes-adapted control diet. The magnitude of BA reduction was directly correlated with a decrease in proinsulin.

Hypocaloric, plant-based oatmeal interventions in the treatment of poorly-controlled type 2 diabetes: A review

BACKGROUND

Lifestyle interventions, including dietary modifications, play a key role in the treatment of type 2 diabetes. By the second half of the last century, dietary oatmeal interventions had frequently been used in patients with diabetes; however, with the widespread introduction of insulin, this practice gradually fell into disuse. Within the last decades, the original oatmeal intervention, first described in 1903, has been modified towards a hypocaloric, low-fat, and plant-based intervention.

AIM

The aim of this review was to investigate the current role of these adapted short-term dietary oatmeal interventions in the treatment of patients suffering from poorly-controlled type 2 diabetes. A special focus was put on opportunities for and barriers to its clinical implementation and its potential mechanisms of action.

METHODS

The electronic databases of PubMed and Google Scholar were searched using the keywords "oat," "oats," "oatmeal," and "diabetes."

RESULTS

While there are a limited number of clinical studies including hypocaloric short-term dietary oatmeal interventions, there is evidence that these interventions may lead to a significant decrease in mean blood glucose levels and a significant reduction of insulin dosage in patients suffering from poorly-controlled type 2 diabetes.

CONCLUSION

Modified short-term dietary oatmeal interventions are an effective and economical tool in the treatment of patients suffering from poorly-controlled type 2 diabetes.

Carbon Nanoparticles Inhibit Α-Glucosidase Activity and Induce a Hypoglycemic Effect in Diabetic Mice

New, improved therapies to reduce blood glucose are required for treating diabetes mellitus (DM). Here, we investigated the use of a new nanomaterial candidate for DM treatment, carbon nanoparticles (CNPs). CNPs were prepared by carbonization using a polysaccharide from Arctium lappa L. root as the carbon source. The chemical structure and morphology of the CNPs were characterized using Fourier-transform infrared spectroscopy, X-ray photoelectron spectroscopy, elemental analysis, and transmission electron microscopy. CNPs were spherical, 10-20 nm in size, consisting of C, H, O, and N, and featuring various functional groups, including C=O, C=C, C–O, and C–N. In vitro, the as-prepared CNPs could inhibit α-glucosidase with an IC₅₀ value of 0.5677 mg/mL, which is close to that of the reference drug acarbose. Moreover, in vivo hypoglycemic assays revealed that the CNPs significantly reduced fasting blood-glucose levels in mice with diabetes induced by high-fat diet and streptozocin, lowering blood glucose after intragastric administration for 42 days. To the best of our knowledge, this is the first report of CNPs exhibiting α-glucosidase inhibition and a hypoglycemic effect in diabetic mice. These findings suggest the therapeutic potential of CNPs for diabetes.

Volatile Profiles from Traditional Chinese Oat Meal Varied Significantly from Oat Porridge and Differed with Cultivars and Locations

Volatile profiles of oat-based foods are mainly analyzed on the oat flakes and porridge as snack or breakfast, whereas the volatile characteristics of the traditional Chinese oat meal (TCOM), a popular main food in some regions of northern China, with special strong aroma, are not known. Here, we compared the volatile profiles from headspace solid phase microextraction gas chromatography-mass spectrometry analysis of oat porridge (OP) and TCOM, which were of different processing and cooking methods, from those of different cultivars, and analyzed the effect of cultivation locations on oat volatile features. Apart from the 35 volatiles shared by OP and TCOM, there were 23 and 24 volatiles specific to OP and TCOM, respectively, with the later showing more toasting and frying-related volatiles due to the dry frying process of the grains before milling. Principle component analysis of the volatiles of OP and TCOM from 16 cultivars showed that they were clustered into two groups, and four cultivars were clustered together, independent of processing and cooking methods. The oat volatile profiles of cultivars grown in three regions of north China were dependent on the cultivation locations rather than cultivars, regardless of OP or TCOM, with those from Datong of Shanxi Province and Zhangjiakou of Hebei Province clustered together. The location effect could be due to significant less precipitation in the two regions above than the other region Ulanqab of Inner Mongolia. PRACTICAL APPLICATION: The volatile compounds in oat are closely related to cultivation regions, which could be applied as a key factor by oat producers for marketing. The four cultivars showed similar and stable volatile profiles, which could be used as reference cultivars for breeding of high-quality oat with better flavor.

Oatmeal interventions in severe insulin resistance on the intensive care unit: A case report

OBJECTIVES

To report on the potential effectiveness of hypocaloric, plant-based short-term dietary oatmeal interventions in the treatment of insulin resistance in critically ill patients on the intensive care unit.

CLINICAL FEATURES AND OUTCOME

A 67-year-old female with type 2 diabetes was admitted to our hospital with suspected pneumonia. The patient developed acute hypoxemic respiratory failure and was diagnosed with pneumogenic sepsis requiring invasive ventilation and an immediate transfer to our medical intensive care unit. Within 48 h the patient developed severe to extreme insulin resistance and required more than 200 units of insulin per day. Based on the "Noorden diet" described in 1903, a modified hypocaloric (700 kcal) and plant-based dietary oatmeal intervention was performed to "break" insulin resistance and to improve glycaemic control. For two days, the patient received a low-fat diet that restricted carbohydrates to whole-grain oats (180 g) and included small amounts of vegetables (60 g). Enteral feeding was done via nasogastric tube. During and after the intervention, glycaemic control improved significantly. A significant reduction in total daily insulin requirements was achieved during and after the intervention.

CONCLUSIONS

Hypocaloric, plant-based short-term dietary oatmeal interventions significantly reduced mean blood glucose levels and mean required daily insulin doses in a critically ill and septic patient on the intensive care unit.

Nutritional strategies in managing postmeal glucose for type 2 diabetes: A narrative review

Medical Nutrition Therapy (MNT) plays an essential role in overall glycemic management. Less focus is given on managing postmeal hyperglycemia despite the facts that, it is a common feature of Type 2 Diabetes (T2D). The purpose of this narrative review is to provide a comprehensive understanding of the existing literature on the nutritional approaches to improve postmeal hyperglycemia in patients with T2D. We searched multiple databases for the studies examining the nutritional approaches to manage postmeal glucose in patients with T2D. We included studies that involve human trials that were published in English for the past 10 years. Our review of the current literature indicates that the postmeal hyperglycemia can be improved with four nutritional approaches. These approaches include (i) utilizing the appropriate amount and selecting the right type of carbohydrates, (ii) using specific types of dietary protein, (iii) manipulating the meal timing and orders and (iv) others (promoting postmeal physical activity, incorporating diabetes-specific formula and certain functional foods). The potential mechanisms underlying these approaches are discussed and the identified gaps warranted further research. This array of nutritional strategies provide a set of options for healthcare professionals to facilitate patients with T2D in achieving the optimal level of postmeal glucose.

DASH Dietary Pattern and Cardiometabolic Outcomes: An Umbrella Review of Systematic Reviews and Meta-Analyses

BACKGROUND

The Dietary Approaches to Stop Hypertension (DASH) dietary pattern, which emphasizes fruit, vegetables, fat-free/low-fat dairy, whole grains, nuts and legumes, and limits saturated fat, cholesterol, red and processed meats, sweets, added sugars, salt and sugar-sweetened beverages, is widely recommended by international diabetes and heart association guidelines.

OBJECTIVE

To summarize the available evidence for the update of the European Association of the Study of Diabetes (EASD) guidelines, we conducted an umbrella review of existing systematic reviews and meta-analyses using the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) approach of the relation of the DASH dietary pattern with cardiovascular disease and other cardiometabolic outcomes in prospective cohort studies and its effect on blood pressure and other cardiometabolic risk factors in controlled trials in individuals with and without diabetes.

METHODS

MEDLINE and EMBASE were searched through 3 January 2019. We included systematic reviews and meta-analyses assessing the relation of the DASH dietary pattern with cardiometabolic disease outcomes in prospective cohort studies and the effect on cardiometabolic risk factors in randomized and non-randomized controlled trials. Two independent reviewers extracted relevant data and assessed the risk of bias of individual studies. The primary outcome was incident cardiovascular disease (CVD) in the prospective cohort studies and systolic blood pressure in the controlled trials. Secondary outcomes included incident coronary heart disease, stroke, and diabetes in prospective cohort studies and other established cardiometabolic risk factors in controlled trials. If the search did not identify an existing systematic review and meta-analysis on a pre-specified outcome, then we conducted our own systematic review and meta-analysis. The evidence was summarized as risk ratios (RR) for disease incidence outcomes and mean differences (MDs) for risk factor outcomes with 95% confidence intervals (95% CIs). The certainty of the evidence was assessed using GRADE.

RESULTS

We identified three systematic reviews and meta-analyses of 15 unique prospective cohort studies (n = 942,140) and four systematic reviews and meta-analyses of 31 unique controlled trials (n = 4,414) across outcomes. We conducted our own systematic review and meta-analysis of 2 controlled trials (n = 65) for HbA1c. The DASH dietary pattern was associated with decreased incident cardiovascular disease (RR, 0.80 (0.76⁻0.85)), coronary heart disease (0.79 (0.71⁻0.88)), stroke (0.81 (0.72⁻0.92)), and diabetes (0.82 (0.74⁻0.92)) in prospective cohort studies and decreased systolic (MD, -5.2 mmHg (95% CI, -7.0 to -3.4)) and diastolic (-2.60 mmHg (-3.50 to -1.70)) blood pressure, Total-C (-0.20 mmol/L (-0.31 to -0.10)), LDL-C (-0.10 mmol/L (-0.20 to -0.01)), HbA1c (-0.53% (-0.62, -0.43)), fasting blood insulin (-0.15 μU/mL (-0.22 to -0.08)), and body weight (-1.42 kg (-2.03 to -0.82)) in controlled trials. There was no effect on HDL-C, triglycerides, fasting blood glucose, HOMA-IR, or CRP. The certainty of the evidence was moderate for SBP and low for CVD incidence and ranged from very low to moderate for the secondary outcomes.

CONCLUSIONS

Current evidence allows for the conclusion that the DASH dietary pattern is associated with decreased incidence of cardiovascular disease and improves blood pressure with evidence of other cardiometabolic advantages in people with and without diabetes. More research is needed to improve the certainty of the estimates.