Consumption of 100% Fruit Juice and Body Weight in Children and Adults: A Systematic Review and Meta-Analysis

Importance

Concerns have been raised that frequent consumption of 100% fruit juice may promote weight gain. Current evidence on fruit juice and weight gain has yielded mixed findings from both observational studies and clinical trials.

Objective

To synthesize the available evidence on 100% fruit juice consumption and body weight in children and adults.

Data Sources

MEDLINE, Embase, and Cochrane databases were searched through May 18, 2023.

Study Selection

Prospective cohort studies of at least 6 months and randomized clinical trials (RCTs) of at least 2 weeks assessing the association of 100% fruit juice with body weight change in children and adults were included. In the trials, fruit juices were compared with noncaloric controls.

Data Extraction and Synthesis

Data were pooled using random-effects models and presented as β coefficients with 95% CIs for cohort studies and mean differences (MDs) with 95% CIs for RCTs.

Main Outcomes and Measures

Change in body mass index (BMI; calculated as weight in kilograms divided by height in meters squared) was assessed in children and change in body weight in adults.

Results

A total of 42 eligible studies were included in this analysis, including 17 among children (17 cohorts; 0 RCTs; 45 851 children; median [IQR] age, 8 [1-15] years) and 25 among adults (6 cohorts; 19 RCTs; 268 095 adults; median [IQR] age among cohort studies, 48 [41-61] years; median [IQR] age among RCTs, 42 [25-59]). Among cohort studies in children, each additional serving per day of 100% fruit juice was associated with a 0.03 (95% CI, 0.01-0.05) higher BMI change. Among cohort studies in adults, studies that did not adjust for energy showed greater body weight gain (0.21 kg; 95% CI, 0.15-0.27 kg) than studies that did adjust for energy intake (-0.08 kg; 95% CI, -0.11 to -0.05 kg; P for meta-regression <.001). RCTs in adults found no significant association of assignment to 100% fruit juice with body weight but the CI was wide (MD, -0.53 kg; 95% CI, -1.55 to 0.48 kg).

Conclusion and Relevance

Based on the available evidence from prospective cohort studies, in this systematic review and meta-analysis, 1 serving per day of 100% fruit juice was associated with BMI gain among children. Findings in adults found a significant association among studies unadjusted for total energy, suggesting potential mediation by calories. Further trials of 100% fruit juice and body weight are desirable. Our findings support guidance to limit consumption of fruit juice to prevent intake of excess calories and weight gain.

Vegetable and Fruit Intake Variety and Cardiovascular Health and Mortality: A Systematic Review and Meta-Analysis of Observational Studies

INTRODUCTION

A multitude of evidence supports the consumption of a higher quantity of vegetables and fruits for their cardiovascular benefits. Nonetheless, the extent to which variety is associated with cardiovascular health remains unclear.

OBJECTIVE

To conduct a systematic review and meta-analysis of observational studies (prospective cohort and cross-sectional studies) assessing the role of a variety of vegetable and fruit consumption in cardiovascular morbidity and mortality in adults.

DATA SOURCES

MEDLINE-PubMed, Cochrane databases, and reference lists were searched through March 2023.

DATA EXTRACTION

Two independent reviewers extracted data and assessed the risk of bias (National Heart, Lung, and Blood Institute Tool and Newcastle-Ottawa Scale).

DATA ANALYSIS

Data were pooled (fixed and random [DerSimonian and Laird] effects for <5 and ≥5 study comparisons, respectively), and heterogeneity was assessed using the Cochran Q statistic and quantified (I2 statistic). The Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) was used to assess the overall certainty of the evidence. Five cross-sectional (n = 45,761) and seven prospective studies (n = 253,422) met the eligibility criteria. Greater variety of vegetable and fruit consumption was prospectively related to decreased all-cause mortality (risk ratio, 0.89 [95% CI, 0.82-0.97], seven study comparisons, n = 196,925), while no significant associations were observed with assessed cardiovascular-related mortality or morbidity. For all outcomes, the certainty of the evidence was graded as "low" or "very low" owing to inconsistency and/or imprecision.

CONCLUSIONS

Overall, this study shows that greater variety in vegetable and fruit consumption may reduce all-cause mortality and highlights the need for additional studies with a higher degree of evidence to better understand its role in cardiovascular health.

Fructose-containing food sources and blood pressure: A systematic review and meta-analysis of controlled feeding trials

Whether food source or energy mediates the effect of fructose-containing sugars on blood pressure (BP) is unclear. We conducted a systematic review and meta-analysis of the effect of different food sources of fructose-containing sugars at different levels of energy control on BP. We searched MEDLINE, Embase and the Cochrane Library through June 2021 for controlled trials ≥7-days. We prespecified 4 trial designs: substitution (energy matched substitution of sugars); addition (excess energy from sugars added); subtraction (excess energy from sugars subtracted); and ad libitum (energy from sugars freely replaced). Outcomes were systolic and diastolic BP. Independent reviewers extracted data. GRADE assessed the certainty of evidence. We included 93 reports (147 trial comparisons, N = 5,213) assessing 12 different food sources across 4 energy control levels in adults with and without hypertension or at risk for hypertension. Total fructose-containing sugars had no effect in substitution, subtraction, or ad libitum trials but decreased systolic and diastolic BP in addition trials (P<0.05). There was evidence of interaction/influence by food source: fruit and 100% fruit juice decreased and mixed sources (with sugar-sweetened beverages [SSBs]) increased BP in addition trials and the removal of SSBs (linear dose response gradient) and mixed sources (with SSBs) decreased BP in subtraction trials. The certainty of evidence was generally moderate. Food source and energy control appear to mediate the effect of fructose-containing sugars on BP. The evidence provides a good indication that fruit and 100% fruit juice at low doses (up to or less than the public health threshold of ~10% E) lead to small, but important reductions in BP, while the addition of excess energy of mixed sources (with SSBs) at high doses (up to 23%) leads to moderate increases and their removal or the removal of SSBs alone (up to ~20% E) leads to small, but important decreases in BP in adults with and without hypertension or at risk for hypertension. Trial registration: Clinicaltrials.gov: NCT02716870.

The Effect of Food is Medicine Interventions on Diabetes-related Health Outcomes Among Low-income and Food-insecure Individuals: A Systematic Review and Meta-analysis

OBJECTIVE

In this study, we aim to review the current evidence of Food is Medicine interventions on diabetes outcomes among low-income or food-insecure individuals.

METHODS

Seven databases were searched from January 1, 2000 to October 26, 2021 for full-text articles written in English. The studies included experimental studies of any duration and design which addressed the effect of Food is Medicine interventions on fruit and vegetable (F&V) intake and glycated hemoglobin (A1C) levels among low-income or food-insecure populations with prediabetes or diabetes of any age group. Only direction of effect of interventions on F&V intake were ascertained due to high variability in outcome measurement. A1C results were pooled using generic inverse variance with a fixed-effects model. Heterogeneity was assessed using Cochran's Q and quantified by I².

RESULTS

Sixteen studies were included. Five of the 8 studies reported a significant increase in F&V intake. Seven of the 14 studies reported a significant decrease in A1C levels. A meta-analysis of 5 randomized controlled trials (n=843) resulted in clinically meaningful reductions in A1C compared with control (mean difference, -0.47%; 95% confidence interval, -0.66 to -0.29, I²=88%, p<0.0001). Half (n=8) of the studies have a high risk of bias due to missing data, detection bias, and confounding.

CONCLUSIONS

Food is Medicine interventions are effective in increasing F&V intake and reducing A1C levels of the target population. More randomized controlled studies are needed to validate the results.

Abstract P521: Association Between Dietary Phytosterols and Risk of Cardiovascular Disease Mortality in US Adults: Findings From the Third National Health and Nutrition Examination Survey (NHANES III), 1988-1994

Introduction: Phytosterols (plant sterols) are naturally occurring components of plant food sources, including vegetable oils, nuts, cereals and legumes. Their chemical structure impedes intestinal cholesterol absorption and regular consumption has been related to lower serum low-density cholesterol (LDL-C), a causal risk factor for cardiovascular disease (CVD). The association between dietary plant sterol intake and CVD has yet to be determined.

Objective: We aimed to examine the association of phytosterol consumption in the diet with cardiovascular mortality in US adults the National Health & Nutrition Examination Survey III (NHANES III), 1988-1994.

Methods: We conducted a prospective cohort analysis on National Health and Nutrition Examination Survey (NHANES, 1988-1994 [III]), linked with the National Death Index mortality data (2015) to associate dietary phytosterol intake from 24h dietary recall data with CVD mortality. We included 13,004 adults aged ≥20 years who were non-pregnant, free of CVD at baseline and completed ≥1 24h dietary recall with plausible caloric intake data. We excluded individuals with death occurring within 1 year of baseline. We created a database quantifying the phytosterol content of foods in the 24h dietary recall data and estimated usual intake by quintiles using the NCI method. We determined the risk function by regression calibration and estimated CVD mortality risk between the 10 th (Q1) and 90 th (Q5) percentiles of usual intake. Data was adjusted for sex, age, smoking status and ethnicity.

Results: Over a mean±SD follow-up period of 21.2±5.1y, 949 CVD deaths occurred in a population with a mean±SD age of 44.2±14.3y, BMI 26.7±4.7 kg/m 2 and mean dietary plant sterol usual intake of 272.3 mg/day. The top sources of dietary phytosterols were from potatoes 23%), wheat and other grains (21%) and beans, legumes and nuts (13%). Mean usual intake plant intake in the 10 th (Q1) and 90 th (Q5) percentiles of the population was 150.1 and 414.0 mg/day. The estimated relative risk for CVD mortality between Q1 (ref) and Q5 was 0.972 (p<0.05).

Conclusions: Preliminary analyses suggest a CVD death risk reduction of 2.8% in the highest versus lowest intakes of dietary plant sterols in the US population. We plan to expand the multivariable model to include the Healthy Eating Index (diet quality) and assess stratification by healthful and unhealthful sources of phytosterols and linear and non-linear dose response analyses to determine the robustness of the association.

OSF Registration: osf.io/da4sg

Funding: Amgen Scholars Program, Canadian Institutes of Health Research (CIHR), Banting and Best Diabetes Centre (BBDC), Toronto 3D Knowledge Synthesis and Clinical Trials foundation

Important food sources of fructose-containing sugars and adiposity: A systematic review and meta-analysis of controlled feeding trials

BACKGROUND

Sugar-sweetened beverages (SSBs) providing excess energy increase adiposity. The effect of other food sources of sugars at different energy control levels is unclear.

OBJECTIVES

To determine the effect of food sources of fructose-containing sugars by energy control on adiposity.

METHODS

In this systematic review and meta-analysis, MEDLINE, Embase, and Cochrane Library were searched through April 2022 for controlled trials ≥2 wk. We prespecified 4 trial designs by energy control: substitution (energy-matched replacement of sugars), addition (energy from sugars added), subtraction (energy from sugars subtracted), and ad libitum (energy from sugars freely replaced). Independent authors extracted data. The primary outcome was body weight. Secondary outcomes included other adiposity measures. Grading of Recommendations Assessment, Development, and Evaluation (GRADE) was used to assess the certainty of evidence.

RESULTS

We included 169 trials (255 trial comparisons, n = 10,357) assessing 14 food sources at 4 energy control levels over a median 12 wk. Total fructose-containing sugars increased body weight (MD: 0.28 kg; 95% CI: 0.06, 0.50 kg; P_MD = 0.011) in addition trials and decreased body weight (MD: -0.96 kg; 95% CI: -1.78, -0.14 kg; P_MD = 0.022) in subtraction trials with no effect in substitution or ad libitum trials. There was interaction/influence by food sources on body weight: substitution trials [fruits decreased; added nutritive sweeteners and mixed sources (with SSBs) increased]; addition trials [dried fruits, honey, fruits (≤10%E), and 100% fruit juice (≤10%E) decreased; SSBs, fruit drink, and mixed sources (with SSBs) increased]; subtraction trials [removal of mixed sources (with SSBs) decreased]; and ad libitum trials [mixed sources (with/without SSBs) increased]. GRADE scores were generally moderate. Results were similar across secondary outcomes.

CONCLUSIONS

Energy control and food sources mediate the effect of fructose-containing sugars on adiposity. The evidence provides a good indication that excess energy from sugars (particularly SSBs at high doses ≥20%E or 100 g/d) increase adiposity, whereas their removal decrease adiposity. Most other food sources had no effect, with some showing decreases (particularly fruits at lower doses ≤10%E or 50 g/d). This trial was registered at clinicaltrials.gov as NCT02558920 (https://clinicaltrials.gov/ct2/show/NCT02558920).

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 (HbA_1c, 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%, p_Q<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], p_MD=0.05; substantial heterogeneity: I²=89%, p_Q<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.

The association between parents' stress and parental feeding practices and feeding styles: Systematic review and meta-analysis of observational studies

In the extended UNICEF framework of early childhood nutrition, parents' stress is associated with parental feeding style. However, no comprehensive review has examined the association between parents' stress and feeding styles and practices. The objective of our review was to synthesise the current literature examining the association between parents' stress and their feeding practices and/or styles, among parents of children ≤ 5 years old. We searched; MEDLINE, EMBASE, PSYCHINFO and CINAHL from 2019 to 2021. Two investigators independently extracted relevant data and assessed the study quality and the certainty of evidence. Data were pooled using generic inverse variance with fixed effects (<5 comparisons) or random effects (≥5 comparisons) and expressed as correlation coefficients with 95% confidence intervals (CI). Between study heterogeneity was assessed using Cochran's Q and quantified with I² . We identified 6 longitudinal and 11 cross-sectional studies, of which 4 studies provided sufficient data to be pooled. A very small correlation between general stress and restrictive feeding practices was observed (r = 0.06 [95% CI: 0.01-0.12]; no substantial heterogeneity (I²  = 0.00%, P_Q  < 0.85, very low certainty). No correlation between general stress and feeding pressure was identified (r = 0.06 [95% CI: -0.02 to 0.15]). Results showed that both general and parenting stress were associated with suboptimal breastfeeding practices and unresponsive feeding styles. Conclusion: This study demonstrated a low-to-moderate quality of literature for the inclusion of parents' stress in the extended UNICEF care model of child nutrition. Future research needs to explore this relationship longitudinally and in ethnic diverse populations to inform tailored interventions that promote responsive feeding practices.

Are all fibres created equal with respect to lipid lowering? Comparing the effect of viscous dietary fibre to non-viscous fibre from cereal sources: a systematic review and meta-analysis of randomised controlled trials

Although compelling evidence from observational studies supports a positive association between consumption of cereal fibre and CVD risk reduction, randomised controlled trials (RCT) often target viscous fibre type as the prospective contributor to lipid lowering to reduce CVD risk. The objective of our study is to compare the lipids-lowering effects of viscous dietary fibre to non-viscous, cereal-type fibre in clinical studies. RCT that evaluated the effect of viscous dietary fibre compared with non-viscous, cereal fibre on LDL cholesterol and alternative lipid markers, with a duration of ≥ 3 weeks, in adults with or without hypercholesterolaemia were included. Medline, EMBASE, CINAHL and the Cochrane Central Register were searched through October 19, 2021. Data were extracted and assessed by two independent reviewers. The generic inverse variance method with random effects model was utilised to pool the data which were expressed as mean differences (MD) with 95 % CI. Eighty-nine trials met eligibility criteria (n 4755). MD for the effect of viscous dietary fibre compared with non-viscous cereal fibre were LDL cholesterol (MD = -0·26 mmol/l; 95 % CI: -0·30, -0·22 mmol/l; P < 0·01), non-HDL cholesterol (MD = -0·33 mmol/l; 95 % CI: -0·39, -0·28 mmol/l; P < 0·01) and Apo-B (MD = -0·04 g/l; 95 % CI: -0·06, -0·03 g/l; P < 0·01). Viscous dietary fibre reduces LDL cholesterol and alternative lipid markers relative to the fibre from cereal sources, hence may be a preferred type of fibre-based dietary intervention targeting CVD risk reduction.

Important Food Sources of Fructose-Containing Sugars and Non-Alcoholic Fatty Liver Disease: A Systematic Review and Meta-Analysis of Controlled Trials

Background: Fructose providing excess calories in the form of sugar sweetened beverages (SSBs) increases markers of non-alcoholic fatty liver disease (NAFLD). Whether this effect holds for other important food sources of fructose-containing sugars is unclear. To investigate the role of food source and energy, we conducted a systematic review and meta-analysis of controlled trials of the effect of fructose-containing sugars by food source at different levels of energy control on non-alcoholic fatty liver disease (NAFLD) markers. Methods and Findings: MEDLINE, Embase, and the Cochrane Library were searched through 7 January 2022 for controlled trials ≥7-days. Four trial designs were prespecified: substitution (energy-matched substitution of sugars for other macronutrients); addition (excess energy from sugars added to diets); subtraction (excess energy from sugars subtracted from diets); and ad libitum (energy from sugars freely replaced by other macronutrients). The primary outcome was intrahepatocellular lipid (IHCL). Secondary outcomes were alanine aminotransferase (ALT) and aspartate aminotransferase (AST). Independent reviewers extracted data and assessed risk of bias. The certainty of evidence was assessed using GRADE. We included 51 trials (75 trial comparisons, n = 2059) of 10 food sources (sugar-sweetened beverages (SSBs); sweetened dairy alternative; 100% fruit juice; fruit; dried fruit; mixed fruit sources; sweets and desserts; added nutritive sweetener; honey; and mixed sources (with SSBs)) in predominantly healthy mixed weight or overweight/obese younger adults. Total fructose-containing sugars increased IHCL (standardized mean difference = 1.72 [95% CI, 1.08 to 2.36], p < 0.001) in addition trials and decreased AST in subtraction trials with no effect on any outcome in substitution or ad libitum trials. There was evidence of influence by food source with SSBs increasing IHCL and ALT in addition trials and mixed sources (with SSBs) decreasing AST in subtraction trials. The certainty of evidence was high for the effect on IHCL and moderate for the effect on ALT for SSBs in addition trials, low for the effect on AST for the removal of energy from mixed sources (with SSBs) in subtraction trials, and generally low to moderate for all other comparisons. Conclusions: Energy control and food source appear to mediate the effect of fructose-containing sugars on NAFLD markers. The evidence provides a good indication that the addition of excess energy from SSBs leads to large increases in liver fat and small important increases in ALT while there is less of an indication that the removal of energy from mixed sources (with SSBs) leads to moderate reductions in AST. Varying uncertainty remains for the lack of effect of other important food sources of fructose-containing sugars at different levels of energy control.

Effect of coadministration of enriched Korean Red Ginseng (Panax ginseng) and American ginseng (Panax quinquefolius L) on cardiometabolic outcomes in type-2 diabetes: A randomized controlled trial

Background

Diabetes mellitus and hypertension often occur together, amplifying cardiovascular disease (CVD) risk and emphasizing the need for a multitargeted treatment approach. American ginseng (AG) and Korean Red Ginseng (KRG) species could improve glycemic control via complementary mechanisms. Additionally, a KRG-inherent component, ginsenoside Rg3, may moderate blood pressure (BP). Our objective was to investigate the therapeutic potential of coadministration of Rg3-enriched Korean Red Ginseng (Rg3-KRG) and AG, added to standard of care therapy, in the management of hypertension and cardiometabolic risk factors in type-2 diabetes.

Methods

Within a randomized controlled, parallel design of 80 participants with type-2 diabetes (HbA1c: 6.5–8%) and hypertension (systolic BP: 140–160 mmHg or treated), supplementation with either 2.25 g/day of combined Rg3-KRG + AG or wheat-bran control was assessed over a 12-wk intervention period. The primary endpoint was ambulatory 24-h systolic BP. Additional endpoints included further hemodynamic assessment, glycemic control, plasma lipids and safety monitoring.

Results

Combined ginseng intervention generated a mean ± SE decrease in primary endpoint of 24-h systolic BP (−3.98 ± 2.0 mmHg, p = 0.04). Additionally, there was a greater reduction in HbA1c (−0.35 ± 0.1% [–3.8 ± 1.1 mmol/mol], p = 0.02), and change in blood lipids: total cholesterol (−0.50 ± 0.2 mmol/l, p = 0.01), non-HDL-C (−0.54 ± 0.2 mmol/l, p = 0.01), triglycerides (−0.40 ± 0.2 mmol/l, p = 0.02) and LDL-C (−0.35 ± 0.2 mmol/l, p = 0.06) at 12 wks, relative to control. No adverse safety outcomes were observed.

Conclusion

Coadministration of Rg3-KRG + AG is an effective addon for improving BP along with attaining favorable cardiometabolic outcomes in individuals with type 2 diabetes. Ginseng derivatives may offer clinical utility when included in the polypharmacy and lifestyle treatment of diabetes.

Clinical trial registration

Clinicaltrials.gov identifier, NCT01578837;

Neither low salivary amylase activity, cooling cooked white rice, nor single nucleotide polymorphisms in starch-digesting enzymes reduce glycemic index or starch digestibility: a randomized, crossover trial in healthy adults

BACKGROUND

It was suggested that low salivary-amylase activity (SAA) and cooling or stir-frying cooked starch decreases its digestibility and glycemic index.

OBJECTIVE

We determined the effects of SAA, cooling, and single-nucleotide polymorphisms (SNPs) in the salivary amylase (AMY1), pancreatic amylase (AMY2A, AMY2B), maltase-glucoamylase (MGAM), and sucrase-isomaltase (SI) genes on starch digestibility and glycemic index of cooked polished rice.

METHODS

Healthy subjects [pilot, n = 12; main, n = 20 with low-SAA (<50 U/mL), and n = 20 with high-SAA (>105 U/mL)] consumed test meals containing 25 g (pilot) or 50 g (main) available carbohydrate at a contract research organization using open-label (pilot) or assessor-blinded (main), randomized, crossover, Latin-square designs (trial registration: NCT03667963). Pilot-trial test meals were dextrose, freshly cooked polished rice, cooked rice cooled overnight, stir-fried hot rice, or stir-fried cold rice. Main-trial test meals were dextrose, dextrose plus 10 g lactulose, plain hot rice, or plain cold rice. In both trials, blood glucose was measured fasting and at intervals over 2 h. In the main trial, breath hydrogen was measured fasting and hourly for 6 h to estimate in vivo starch digestibility. Data were analyzed by repeated-measures ANOVA for the main effects of temperature and stir-frying (pilot trial) or the main effects of SAA and temperature (main trial) and their interactions. Effects of 24 single nucleotide polymorphisms (SNPs) were assessed separately. Means were considered to be equivalent if the 95% CI of the differences were within ±20% of the comparator mean for glucose response/glycemic index or ±7% for digestibility.

RESULTS

Pilot: neither temperature nor stir-frying significantly affected glucose incremental AUC (primary endpoint, n = 12). Main: mean ± SEM glycemic index (primary endpoint, n = 40) was equivalent for low-SAA compared with high-SAA (73 ± 3 vs. 75 ± 4) and cold rice compared with hot rice (75 ± 3 vs. 70 ± 3). Estimated starch digestibility (n = 39) was equivalent for low-SAA compared with high-SAA (95% ± 1% vs. 92% ± 1%) and hot rice compared with cold rice (94% ± 1% vs. 93% ± 1%). No meaningful associations were observed between genotypes and starch digestibility or glycemic index for any of the SNPs.

CONCLUSIONS

The results do not support the hypotheses that low-SAA, cooling, and common genetic variations in starch-digesting enzymes affect the glycemic index or in vivo carbohydrate digestibility of cooked polished rice. This trial was registered at clinicaltrials.gov as NCT03667963.

Different Food Sources of Fructose-Containing Sugars and Fasting Blood Uric Acid Levels: A Systematic Review and Meta-Analysis of Controlled Feeding Trials

BACKGROUND

Although fructose as a source of excess calories increases uric acid, the effect of the food matrix is unclear.

OBJECTIVES

To assess the effects of fructose-containing sugars by food source at different levels of energy control on uric acid, we conducted a systematic review and meta-analysis of controlled trials.

METHODS

MEDLINE, Embase, and the Cochrane Library were searched (through 11 January 2021) for trials ≥ 7 days. We prespecified 4 trial designs by energy control: substitution (energy-matched replacement of sugars in diets); addition (excess energy from sugars added to diets); subtraction (energy from sugars subtracted from diets); and ad libitum (energy from sugars freely replaced in diets) designs. Independent reviewers (≥2) extracted data and assessed the risk of bias. Grading of Recommendations, Assessment, Development, and Evaluation was used to assess the certainty of evidence.

RESULTS

We included 47 trials (85 comparisons; N = 2763) assessing 9 food sources [sugar-sweetened beverages (SSBs), sweetened dairy, fruit drinks, 100% fruit juice, fruit, dried fruit, sweets and desserts, added nutritive sweetener, and mixed sources] across 4 energy control levels in predominantly healthy, mixed-weight adults. Total fructose-containing sugars increased uric acid levels in substitution trials (mean difference, 0.16 mg/dL;  95% CI:  0.06-0.27 mg/dL;  P = 0.003), with no effect across the other energy control levels. There was evidence of an interaction by food source: SSBs and sweets and desserts increased uric acid levels in the substitution design, while SSBs increased and 100% fruit juice decreased uric acid levels in addition trials. The certainty of evidence was high for the increasing effect of SSBs in substitution and addition trials and the decreasing effect of 100% fruit juice in addition trials and was moderate to very low for all other comparisons.

CONCLUSIONS

Food source more than energy control appears to mediate the effects of fructose-containing sugars on uric acid. The available evidence provides reliable indications that SSBs increase and 100% fruit juice decreases uric acid levels. More high-quality trials of different food sources are needed. This trial was registered at clinicaltrials.gov as NCT02716870.

Effect of Oats and Oat-Fiber on Glycemic Control in Diabetes: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

Objectives

Current approved health claims in Canada, US and Europe 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 to update the evidence of the effect of oats and oat-fiber on markers of glycemic control in people with and without diabetes. Here we present data for the subgroup with diabetes.

Methods

MEDLINE, EMBASE and the Cochrane Central Register of Controlled Trials were searched through September 23rd, 2020. We included randomized controlled trials of ≥ 2-weeks of sources of oat ß-glucan and measures of glycemic control in diabetes. Two independent reviewers extracted relevant data and assessed the risk of bias (Cochrane Risk of Bias 2.0 Tool). The outcomes were fasting plasma glucose (FPG), 2h-plasma glucose (2h-PG) from a 75 g-oral glucose tolerance test, HbA1c and fasting

plasma insulin (FPI). Data were pooled using the generic inverse variance method. Heterogeneity was assessed (Cochran Q statistic) and quantified (I2 statistic). Pooled estimates were expressed as mean differences with 95% confidence intervals (CI). GRADE assessed the certainty of the evidence.

Results

Eligibility criteria were met by 5 trial comparisons (N = 359) in type 2 diabetes. No trials were identified in type 1 diabetes. Consumption of oat ß-glucan sources reduced FPG (MD = −0.37 mmol/L [95% CI: −0.70, −0.05 mmol/L], P = 0.03, I2 = 0.00%, PQ = 0.76) and 2h-PG (MD = −1.24 mmol/L [95% CI: −1.97, −0.51 mmol/L], P = 0.00, I2 = 0.00%, PQ = 0.56). There were non-significant reductions in HbA1c (MD = −0.12%, [95% CI: −0.26, 0.01%], P = 0.07, I2 = 0.00%, PQ = 1.00) and FPI (MD = −4.59 pmol/L, [95% CI: −14.71, 5.52 pmol/L], P = 0.37, I2 = 40.84%, PQ = 0.19). The certainty of evidence was high for 2h-PG and moderate for FPG, HbA1c and FPI (single downgrades for imprecision in each case).

Conclusions

Current evidence provides a good indication that consumption of oat ß-glucan results in small improvements of glycemic control in type 2 diabetes. More high quality randomized trials are required to improve the precision of the pooled estimates. (ClinicalTrials.gov identifier, NCT04631913)

Funding Sources

Quaker Oats Center of Excellence, Diabetes Canada, Banting & Best Diabetes Centre, Toronto 3D foundation

The Effect of Oat β-Glucan on Postprandial Blood Glucose and Insulin Responses: A Systematic Review and Meta-Analysis

Objectives

The efficacy of oat beta-glucan (OBG), a viscous soluble fibre, on postprandial glycemic outcomes may depend on the nature of the control and the dose and molecular weight (MW) utilized. We undertook a systematic review and meta-analysis of acute clinical trials to determine whether these features mediate the glycemic and insulinaemic responses to OBG.

Methods

MEDLINE, EMBASE, and the Cochrane Central Register of Controlled Trials were searched through October 27, 2020. We included acute, single-meal feeding, controlled trials investigating the effect of OBG (concentrate or oat bran) added to a carbohydrate-containing meal compared to a comparable meal (matched control) or a different carbohydrate-containing meal (unmatched control). Two reviewers extracted the data and assessed the risk of bias and certainty of

evidence (GRADE). The primary outcome was incremental area under the curve (iAUC) for blood glucose. Data were pooled using the generic-inverse variance method with random effects model and expressed as ratio of means with [95% Cis].

Results

One hundred and three  trial comparisons (N = 538) were included. OBG reduced glucose iAUC and iPeak by 23% (0.77 [0.74, 0.81]) and 28% (0.72 [0.64, 0.76]) and insulin by 22% (0.78 [0.72, 0.85]) and 24% (0.76 [0.65, 0.88]), respectively. Dose, molecular-weight and comparator were significant effect modifiers of glucose iAUC and iPeak. Significant linear dose-response relationships were observed for all outcomes. OBG molecular-weight &gt; 300 kg/mol significantly reduced glucose iAUC and iPeak, whereas, molecular-weight &lt; 300 kg/mol did not.  Reductions in glucose iAUC (27 vs 20%, p = 0.03) and iPeak (39 vs 25%, p &lt; 0.01) were significantly larger with different vs comparable control-meals. Outcomes were similar in participants with and without diabetes. All outcomes had high certainty-of-evidence.

Conclusions

Current evidence indicates that the addition of OBG to carbohydrate-containing meals reduces the postprandial glycemic and insulinaemic responses. However, the magnitude of glucose reduction depends on OBG dose, molecular-weight and the comparator.

Funding Sources

INQUIS Clinical Research Ltd. (formerly GI Labs), and PepsiCo Global R&D

Effect of Important Food Sources of Fructose-Containing Sugars on Non-alcoholic Fatty Liver Disease: A Systematic Review and Meta-Analysis of Controlled Trials

Objectives

Fructose as a source of excess calories increases non-alcoholic fatty liver disease (NAFLD) markers. Whether this effect is mediated by the food matrix is unknown. We thus conducted a systematic review and meta-analysis of controlled feeding trials assessing the effect of important food sources of fructose-containing sugars at different energy control levels on NAFLD markers.

Methods

MEDLINE, Embase, and Cochrane Library were searched through January 18, 2021 for controlled trials ≥7-days. Four trial designs were prespecified based on energy control: substitution (energy-matched replacement of sugars by other macronutrients); addition (excess energy from sugars added to diets); subtraction (energy from sugars subtracted from diets); and ad libitum (energy from sugars freely replaced by other macronutrients). The primary outcome was intrahepatocellular lipid (IHCL). Secondary outcomes were alanine aminotransferase (ALT) and aspartate aminotransferase (AST). Independent reviewers extracted data and assessed risk of bias. Certainty of evidence was assessed by GRADE.

Results

We included 44 trials (65 trial comparisons, n = 1941) assessing the effect of 8 food sources (sugar-sweetened beverages [SSBs]; sweetened dairy alternative [soy]; fruit juice; fruit; dried fruit; baked goods, desserts and sweets; added nutritive sweetener; and mixed sources) across 4 energy levels. Total fructose-containing sugars increased IHCL in addition trials (standardized mean difference = 1.69 [95% CI, 1.00–2.37], P &lt; 0.001), but no effect in substitution, subtraction and ad libitum trials. There was evidence of interaction by food source in addition trials with SSBs increasing IHCL and ALT, and mixed sources increasing AST. The overall certainty of evidence was high for SSBs on IHCL and ALT in addition trials and high to very low for all other comparisons.

Conclusions

Energy control and food source appear to mediate the effect of fructose-containing sugars on NAFLD markers. High certainty evidence suggests that SSBs providing excess energy increase NAFLD markers, while the evidence is less certain that mixed sources share the same effect and other food sources do not. More high-quality randomized trials of different food sources are needed to improve our estimates (ClinicalTrials.gov identifier, NCT02716870).

Funding Sources

Primary funding: Diabetes Canada.

Relation of Food Sources of Fructose Containing Sugars With Incident Obesity Outcomes: A Systematic Review and Meta-Analysis of Prospective Cohort Studies

Objectives

Sugars have been implicated in the epidemic of obesity. It is unclear whether food sources of fructose-containing sugars other than sugar-sweetened beverages (SSBs) are associated with increased risk of obesity. To assess the evidence of the relation of food sources of fructose-containing sugars with incident overweight or obesity, we undertook a systematic review and meta-analysis of prospective cohort studies.

Methods

We searched MEDLINE, EMBASE and Cochrane Library through Aug 2019. We included prospective cohort studies of ≥1 year. Two reviewers extracted data and assessed the risk of bias. The primary outcome was incident overweight/obesity. Data were pooled using generic-inverse variance method (random effects) and expressed as relative risks (RR) for incident outcomes and ß-coefficients for WC with 95% confidence intervals (CI). GRADE assessed the certainty of evidence

Results

We included 12 and 8 prospective cohorts involving 181,295 adults and 31,717 children, respectively. Four food sources of fructose-containing sugars were identified: SSBs, 100% fruit juice, fruit and yogurt. There was no data available in children for yogurt or WC. SSBs were associated with increased incident overweight/obesity in children (RR, 1.22 [95% CI, 1.03 to 1.44] but not in adults and increased incident abdominal obesity in both children (3.78 [1.08 to 13.25]) and adults (1.51 [1.11 to 2.06]), but there was no association with change in WC in adults. Fruit juice was associated with increased incident overweight/obesity in children (1.28 [1.07 to 1.53]) but not in adults, and there was no association with incident abdominal obesity in either children or adults or WC in adults. Fruit was associated with decreased incident overweight/obesity (0.87 [0.82 to 0.92]) and decreased WC (ß, −0.23 cm [−0.33 to −0.13]) in adults. Yogurt was associated with decreased incident abdominal obesity (0.65 [0.47 to 0.90]) in adults with no data available on WC. The certainty of the evidence was graded as “very low” to “moderate”.

Conclusions

Current evidence indicates that the relation between fructose-containing sugars and obesity outcomes differs by food sources. More research of more food sources of sugars is needed to improve our certainty in the evidence. (ClinicalTrials.gov, NCT02558920)

Funding Sources

ASN, Diabetes Canada, Banting and Best Diabetes Centre.

Important Food Sources of Fructose-Containing Sugars and Fasting Serum Uric Acid Levels: A Systematic Review and Meta-Analysis of Controlled Feeding Trials

Objectives

Fructose as a source of excess calories increases uric acid. Whether this effect is mediated by the food matrix at different levels of energy is unknown. We aim to conduct a systematic review and meta-analysis of controlled feeding trials on the effect of food sources of fructose-containing sugars at different energy levels on uric acid (NCT02716870).

Methods

MEDLINE, Embase and the Cochrane Library were searched through January 27, 2020 for controlled trials ≥7-days assessing the effect of food sources of fructose-containing sugars on uric acid. Trial designs were prespecified based on energy control: substitution (energy matched replacement of sugars by other macronutrients); addition (excess energy from sugars added to diets); subtraction (energy from sugars subtracted from diets); and ad libitum (energy from sugars freely replaced by other macronutrients) trials. Independent reviewers extracted data and assessed risk of bias. Certainty of evidence was assessed using the GRADE approach.

Results

Eligibility was met by 41 trials (72 trial comparisons, N = 2109) assessing the effect of 9 food sources (sugar-sweetened beverages [SSBs], sweetened dairy, fruit drink [lemonade], 100% fruit juice, fruit, dried fruit [raisins], baked goods desserts and sweets, added nutritive [caloric] sweetener and mixed sources) across the 4 energy levels. Total fructose-containing sugars increased uric acid in substitution trials (mean difference, 0.15 mg/dL [95% confidence interval, 0.03 to 0.27 mg/dL], P = 0.012) with no effect in addition, subtraction or ad libitum trials. There was evidence of interaction by food source with SSBs and baked goods, desserts and sweets increasing uric acid in substitution and SSBs increasing and 100% fruit juice decreasing uric acid in addition trials. The overall certainty of evidence was moderate for the increasing effect of SSBs in substitution and addition trials and low to very low for all other comparisons.

Conclusions

Food source more than energy control mediate the effect of fructose-containing sugars on uric acid. SSBs and baked goods, desserts and sweets appear to increase, and 100% fruit juice appear to decrease uric acid. More high-quality trials of different food sources of fructose-containing sugars are needed to improve our estimates.

Funding Sources

Diabetes Canada.

Important Food Sources of Fructose-Containing Sugars and Postprandial Lipids: A Systematic Review and Meta-Analysis of Controlled Feeding Trials

Objectives

Fructose providing excess calories has been shown to increase postprandial triglycerides (TAG). Whether this effect holds for different food sources of fructose-containing sugars is unclear. We conducted a systematic review and meta-analysis of controlled feeding trials on the effect of different food sources of fructose-containing sugars at different levels of energy control on postprandial blood lipids (NCT02716870).

Methods

MEDLINE, EMBASE, and Cochrane Library were searched through June 1st, 2020 for controlled feeding trials ≥7-days assessing the effect of food sources of fructose-containing sugars on postprandial lipids. Trial designs were prespecified based on energy control: substitution (energy matched replacement of sugars by other macronutrients); addition (excess energy from sugars added to diets); subtraction (energy from sugars subtracted from diets); and ad libitum (energy from sugars freely replaced by other macronutrients) trials. Independent reviewers extracted data and assessed risk of bias. Outcomes were postprandial TAG and apoB48. Certainty of evidence was assessed using GRADE.

Results

We included 29 trials (60 trial comparisons, N = 943) assessing 5 food sources (SSBs, fruit, sweets and desserts, added caloric sweetener and mixed sources) across 4 levels of energy control. Total fructose-containing sugars increased postprandial TAG in substitution (MD: 0.17 mmol/L [95% CI: 0.05, 0.30], P = 0.007), addition (0.38 mmol/L [0.13, 0.62], P = 0.003), and ad libitum (0.17 mmol/L [0.02, 0.31], P = 0.024) trials and increased apoB48 in addition trials (0.12 g/L [0.07, 0.18], P &lt; 0.001).There was evidence of interaction by food source with SSBs increasing postprandial TAG and apoB48 in addition trials and mixed sources increasing postprandial TAG in ad libitum trials. The certainty of the evidence was “moderate” for SSBs increasing TAG in addition trials and mixed sources increasing TAG in ad libitum trials and “low” for all other comparisons.

Conclusions

Food source more than energy control appears to mediate fructose-containing sugars on postprandial lipids. Good evidence suggests that SSBs and mixed sources increase postprandial lipids while evidence is less certain for the lack of effect of other food sources. More high-quality trials of different food sources are needed.

Funding Sources

Primary: Diabetes Canada.

Acute glycemic and insulin response of Fossence™ alone, or when substituted or added to a carbohydrate challenge: A three-phase, acute, randomized, cross-over, double blind clinical trial

Short chain fructo-oligosaccharides (scFOS) are well-recognized prebiotic fibers. Fossence™ (FOSS) is a scFOS that has been produced from sucrose via a proprietary fermentation process and has not been tested for its digestibility or glucose/insulin response (GR and IR, respectively). The present randomized, controlled, cross-over study was conducted in 3 phases to explore GR and IR to ingestion of FOSS, when replaced by/added to available-carbohydrates (avCHO) among 25 healthy adults (40 ± 14years). In each phase GR and IR elicited by 3-4 test-meals were measured among the fasted recruited subjects. The interventional test meals were as follows: Phase-1, water alone or 10g FOSS or 10g Dextrose in 250ml water; Phase-2, 250ml water containing Dextrose:FOSS (g:g) in the content as 50:0 or 50:15 or 35:0 or 35:15; Phase-3 portions of white-bread (WB) containing avCHO:FOSS (g:g) in the content as 50:0 or 50:15 or 35:0 or 35:15. Blood samples (finger prick method) were collected at fasting and 15, 30, 45, 60, 90 and 120 min after start of test meal ingestion. Plasma glucose and serum insulin were analyzed utilizing standard methods. The primary endpoint was differences in glucose IAUC. All subjects provided their written consent to participate in the study (ClinicalTrials.gov: NCT03755232). The results demonstrated that FOSS, when consumed alone, showed no raise in glycaemia or insulinemia and was statistically equivalent to response of water alone. GR and IR elicited by dextrose:FOSS and WB:FOSS test-meals of Phase 2 and Phase 3, were statistically equivalent to the respective test-meals without FOSS. Result of the 3 phases support the hypothesis that FOSS is resistant to breakdown and is indigestible in the human small-intestine, and therefore can be classified as an unavailable carbohydrate that does not raise post prandial blood glucose or insulin. FOSS, being sweet to taste, may be an acceptable sugar replacer in beverages without compromising their taste and sensory qualities.

The effect of oat β-glucan on postprandial blood glucose and insulin responses: a systematic review and meta-analysis

To determine the effect of oat β‑glucan (OBG) on acute glucose and insulin responses and identify significant effect modifiers we searched the MEDLINE, EMBASE, and Cochrane databases through October 27, 2020 for acute, crossover, controlled feeding trials investigating the effect of adding OBG (concentrate or oat-bran) to carbohydrate-containing test-meals compared to comparable or different carbohydrate-matched control-meals in humans regardless of health status. The primary outcome was glucose incremental area-under-the-curve (iAUC). Secondary outcomes were insulin iAUC, and glucose and insulin incremental peak-rise (iPeak). Two reviewers extracted the data and assessed risk-of-bias and certainty-of-evidence (GRADE). Data were pooled using generic inverse-variance with random-effects model and expressed as ratio-of-means with [95% CIs]. We included 103 trial comparisons (N = 538). OBG reduced glucose iAUC and iPeak by 23% (0.77 [0.74, 0.81]) and 28% (0.72 [0.64, 0.76]) and insulin by 22% (0.78 [0.72, 0.85]) and 24% (0.76 [0.65, 0.88]), respectively. Dose, molecular-weight, and comparator were significant effect modifiers of glucose iAUC and iPeak. Significant linear dose-response relationships were observed for all outcomes. OBG molecular-weight >300 kg/mol significantly reduced glucose iAUC and iPeak, whereas molecular-weight <300 kg/mol did not. Reductions in glucose iAUC (27 vs 20%, p = 0.03) and iPeak (39 vs 25%, p < 0.01) were significantly larger with different vs comparable control-meals. Outcomes were similar in participants with and without diabetes. All outcomes had high certainty-of-evidence. In conclusion, current evidence indicates that adding OBG to carbohydrate-containing meals reduces glycaemic and insulinaemic responses. However, the magnitude of glucose reduction depends on OBG dose, molecular-weight, and the comparator.

Co-administration of viscous fiber, Salba-chia and ginseng on glycemic management in type 2 diabetes: a double-blind randomized controlled trial

PURPOSE

Viscous dietary fiber, functional seeds and ginseng roots have individually been proposed for the management of diabetes. We explored whether their co-administration would improve glycemic control in type 2 diabetes beyond conventional therapy.

METHODS

In a randomized, double-blind, controlled trial conducted at two academic centers (Toronto, Canada and Zagreb, Croatia), individuals with type 2 diabetes were assigned to either an active intervention (10 g viscous fiber, 60 g white chia seeds, 1.5 g American and 0.75 g Korean red ginseng extracts), or energy and fiber-matched control (53 g oat bran, 25 g inulin, 25 g maltodextrose and 2.25 g wheat bran) intervention for 24 weeks, while on conventional standard of care. The prespecified primary endpoint was end difference at week 24 in HbA1c, following an intent-to-treat analysis adjusted for center and baseline.

RESULTS

Between January 2016 and April 2018, 104 participants (60M:44F; mean ± SEM age 59 ± 0.8 years; BMI 29.0 ± 0.4 kg/m²; HbA1c 7.0 ± 0.6%) managed with antihyperglycemic agent(s) (n = 98) or lifestyle (n = 6), were randomized (n = 52 test; n = 52 control). At week 24, HbA1c levels were 0.27 ± 0.1% lower on test compared to control (p = 0.03). There was a tendency towards an interaction by baseline HbA1c (p = 0.07), in which a greater reduction was seen in participants with baseline HbA1c > 7% vs ≤ 7% (- 0.56 ± 0.2% vs 0.03 ± 0.2%). Diet and body weight remained unchanged. The interventions were well tolerated with no related adverse events and with high retention rate of 84%.

CONCLUSIONS

Co-administration of selected dietary and herbal therapies was well-tolerated and may provide greater glycemic control as add-on therapy in type 2 diabetes. Registration: Clinicaltrials.gov NCT02553382 (registered on September 17, 2015).

Relation of Different Fruit and Vegetable Sources With Incident Cardiovascular Outcomes: A Systematic Review and Meta-Analysis of Prospective Cohort Studies

Background Public health policies reflect concerns that certain fruit sources may not have the intended benefits and that vegetables should be preferred to fruit. We assessed the relation of fruit and vegetable sources with cardiovascular outcomes using a systematic review and meta-analysis of prospective cohort studies. Methods and Results MEDLINE, EMBASE, and Cochrane were searched through June 3, 2019. Two independent reviewers extracted data and assessed study quality (Newcastle-Ottawa Scale). Data were pooled (fixed effects), and heterogeneity (Cochrane-Q and I2) and certainty of the evidence (Grading of Recommendations Assessment, Development, and Evaluation) were assessed. Eighty-one cohorts involving 4 031 896 individuals and 125 112 cardiovascular events were included. Total fruit and vegetables, fruit, and vegetables were associated with decreased cardiovascular disease (risk ratio, 0.93 [95% CI, 0.89-0.96]; 0.91 [0.88-0.95]; and 0.94 [0.90-0.97], respectively), coronary heart disease (0.88 [0.83-0.92]; 0.88 [0.84-0.92]; and 0.92 [0.87-0.96], respectively), and stroke (0.82 [0.77-0.88], 0.82 [0.79-0.85]; and 0.88 [0.83-0.93], respectively) incidence. Total fruit and vegetables, fruit, and vegetables were associated with decreased cardiovascular disease (0.89 [0.85-0.93]; 0.88 [0.86-0.91]; and 0.87 [0.85-0.90], respectively), coronary heart disease (0.81 [0.72-0.92]; 0.86 [0.82-0.90]; and 0.86 [0.83-0.89], respectively), and stroke (0.73 [0.65-0.81]; 0.87 [0.84-0.91]; and 0.94 [0.90-0.99], respectively) mortality. There were greater benefits for citrus, 100% fruit juice, and pommes among fruit sources and allium, carrots, cruciferous, and green leafy among vegetable sources. No sources showed an adverse association. The certainty of the evidence was "very low" to "moderate," with the highest for total fruit and/or vegetables, pommes fruit, and green leafy vegetables. Conclusions Fruits and vegetables are associated with cardiovascular benefit, with some sources associated with greater benefit and none showing an adverse association. Registration URL: https://www.clini​caltr​ials.gov; Unique identifier: NCT03394339.

Relation of Food Sources of Fructose Containing Sugars with Incident Obesity Outcomes: A Systematic Review and Meta-Analysis of Prospective Cohort Studies

Objectives

Sugars have been implicated in the epidemic of obesity. It is unclear whether food sources of fructose-containing sugars other than sugar-sweetened beverages (SSBs) are associated with increased risk of obesity. To assess the evidence of the relation of food sources of fructose-containing sugars with incident overweight or obesity, we undertook a systematic review and meta-analysis of prospective cohort studies.

Methods

We searched MEDLINE, EMBASE and Cochrane Library through Oct 2018. We included prospective cohort studies of ≥1 year. Two reviewers extracted data and assessed the risk of bias (Newcastle-Ottawa Scale). The primary outcome was incident overweight/obesity. Data were pooled using generic-inverse variance method with random effects model and expressed as relative risks (RR) with 95% confidence intervals (CI). GRADE assessed the certainty of evidence.

Results

We included 20 prospective cohort studies: 9 (n = 25,422; 2614 events) and 6 (n = 119,137; 24,123 events) of incident overweight/obesity and 1 (n = 424; 47 events) and 7 (n = 29,166; 4255 events) of incident abdominal obesity in children and adults, respectively. Three food sources of fructose-containing sugars were identified: SSBs, fruit juice, and yogurt. SSBs were associated with increased incident overweight/obesity in children (RR, 1.22 [95% CI, 1.03 to 1.44] but not in adults and increased incident abdominal obesity in both children (3.78 [1.08 to 13.25]) and adults (1.51 [1.11 to 2.06]). Fruit juice was associated with increased incident overweight/obesity in children (1.28 [1.07 to 1.53]) but not in adults, and there was no association with incident abdominal obesity in either children or adults. Yogurt was associated with decreased incident abdominal obesity (0.65 [0.47 to 0.90]) in adults with no data available for any outcome in children. The certainty of the evidence was graded as very low to low.

Conclusions

Current evidence indicates that the relation between fructose-containing sugars and obesity outcomes differs by food sources. Further research of different food sources of sugars is needed to improve our certainty in the evidence. (ClinicalTrials.gov, NCT02558920)

Funding Sources

American Society for Nutrition Foundation (commissioned and funded), Diabetes Canada.

Comparison of the Acute Glycemic and Insulinemic Response of Fossence™, a Short Chain Fructo-Oligosaccharide, Taken Alone, Added or Substituted into a Carbohydrate Load

Objectives

To explore the physiological response to ingestion of FossenceTM, a short chain fructo-oligosaccharide, when taken alone or when added or substituted into a carbohydrate load.

Methods

In a randomized, controlled, cross-over design, 25 healthy subjects completed three phases (phase 1: 13M:12F; 41 ± 14y; 24.4 ± 2.2 kg/m²; phase 2: 13M:12F; 40 ± 14y; 24.5 ± 2.4 kg/m²; phase 3: 13M:12F; 41 ± 14y; 24.3 ± 2.6 kg/m²; Mean ± SD). On separate days, each subject received in Phase 1: 10 g FossenceTM(10FOS), 10 g Dextrose (10Dex) or a water control (Control); Phase 2: 50 g Dextrose alone (50Dex), Dextrose with 15 g FossenceTM(50Dex + 15FOS), 35 g Dextrose alone (35Dex) or Dextrose with 15 g FossenceTM(35Dex + 15FOS); and Phase 3 received: 50 g available carbohydrate (avCHO) from white bread alone (50WB) or with 15 g FossenceTM(50WB + 15FOS), 35 g avCHO from white bread alone (35WB) or with 15 g FossenceTM(35WB + 15FOS). Blood samples were collected at fasting and over 2 hours after the start of the test meal and analyzed for glucose and insulin levels. The primary endpoint was differences in glucose IAUC. (ClinicalTrials.gov: NCT03755232).

Results

Phase 1: The glucose IAUC was significantly lower after 10FOS and Control compared to 10Dex (P &lt; 0.0001). Similarly, the insulin IAUC was significantly lower after Control and 10FOS compared to 10Dex (P &lt; 0.0001). Phase 2: The glucose IAUC was significantly lower after 35Dex and 35Dex + 15FOS compared to 50Dex (P &lt; 0.0001). Insulin IAUC was significantly lower after 35Dex compared to 50Dex and 50Dex + 15FOS, the IAUC of 35Dex + 15FOS was significantly lower than 50Dex (P &lt; 0.0003). Phase 3: The glucose IAUC was significantly lower after 35WB and 35WB + 15FOS compared to 50WB and 50WB + 15FOS (P &lt; 0.00001). Insulin IAUC was significantly lower after 35WB and 35WB + 15FOS compared to 50WB and 50WB + 15FOS (P &lt; 0.00001).

Conclusions

These studies demonstrate that FossenceTM, when consumed alone, does not increase postprandial glucose and insulin levels, indicating it is resistant to breakdown. When added to a carbohydrate load, no increase in postprandial glucose or insulin levels is observed while substitution of 30% of glycemic carbohydrate by FossenceTMsignificantly decreased postprandial glucose and insulin levels. FossenceTM, being sweet to taste, may be advised to individuals on restricted sugar intake.

Funding Sources

Tata Chemicals Ltd, India.

Effect of soluble-viscous dietary fibre on coronary heart disease risk score across 3 population health categories: data from randomized, double-blind, placebo-controlled trials

We applied the Framingham risk equation in healthy, metabolic syndrome, and diabetes populations, following treatment with viscous fibre from konjac-based blend (KBB). KBB yielded reduction in estimated risk score by 16% (1.04 ± 0.03 vs. 0.87 ± 0.04, p < 0.01) in type 2 diabetes, 24% (1.08 ± 0.01 vs. 0.82 ± 0.02, p < 0.01) in metabolic syndrome, and 25% (1.09 ± 0.05 vs. 0.82 ± 0.06, p < 0.01) in healthy individuals. Drivers for decreased risk were improvements in blood cholesterol and systolic blood pressure. The composite coronary heart disease risk across populations was reduced 22% (p < 0.01). Novelty Viscous fibre from konjac-xanthan reduced 10-year relative coronary heart disease using Framingham Risk Score across the glycemic status spectrum.

Effect of high-carbohydrate or high-monounsaturated fatty acid diets on blood pressure: a systematic review and meta-analysis of randomized controlled trials

Context

Current dietary guidelines for cardiovascular disease risk management recommend restricting intake of saturated fatty acids (SFAs). However, the optimal macronutrient profile, in the context of a low-SFA diet, remains controversial. The blood-pressure effect of replacing SFAs in diets with monounsaturated fatty acids (MUFAs) compared with carbohydrate has not been quantified to date.

Objective

To synthesize the evidence for the effect of substituting a high-carbohydrate (high-CHO) diet for a high-monounsaturated fatty acid (high-MUFA) diet on blood pressure, a systematic review and meta-analysis of randomized clinical trials in a population without health restrictions was conducted.

Data Sources

MEDLINE, EMBASE, and Cochrane Central Register of Controlled Clinical Trials were searched through June 7, 2017. Randomized controlled trials of > 3 weeks duration that assessed the effect of high-MUFA diets in isocaloric substitution for high-CHO diets on systolic blood pressure (SBP) and diastolic blood pressure (DBP) were included.

Data Extraction

Data were pooled using the generic-inverse variance method with random effects models and expressed as mean differences (MDs) with 95% confidence intervals (CIs). Heterogeneity was assessed by Cochran Q statistic and quantified by the I2 statistic. The quality of the evidence was assessed with the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) system.

Results

Fourteen trials (n = 980 participants) were included in the analysis. Comparatively, the high-MUFA diets in isocaloric substitution for high-CHO diets did not demonstrate a greater reduction in blood pressure (SBP: MD, -0.08 mmHg [95%CI, -1.01 to 0.84], P = 0.86; DBP: MD = 0.01 mmHg [95%CI, -0.73 to 0.75], P = 0.98). The overall quality of the evidence was assessed as moderate.

Conclusions

In the context of low SFAs, high-MUFA diets in isocaloric substitution for high-CHO diets did not affect blood pressure in individuals with and without hypertension. Large-scale trials achieving higher MUFA targets are required to support these findings.

ClinicalTrials.gov ID

NCT02626325.

Vascular effects of combined enriched Korean Red ginseng (Panax Ginseng) and American ginseng (Panax Quinquefolius) administration in individuals with hypertension and type 2 diabetes: A randomized controlled trial

BACKGROUND

Type 2 diabetes is known to abrogate the vascular response. Combination of two commonly consumed ginseng species, American ginseng (AG) and a Korean Red ginseng (KRG), enriched with ginsensoide Rg3, was shown to concomitantly improve glucemic control and blood pressure. We evaluated the hypothesis that improvements in central hemodynamics, vascular function and stiffness markers are involved in observed benefits of co-administration.

METHODS

In this randomized, placebo controlled, two-center trial, patients with type 2 diabetes and hypertension were assigned to either 2.25 g ginsenoside Rg3-enriched KRG&AG co-administration or a control 3 times daily for 12-weeks, treated by standard of care. The effects on central hemodynamics, pulse wave velocity (PWV) and endothelial function over the 12-week administration were analyzed.

RESULTS

In intent-to-treat analysis of 80 individuals, a reduction in central systolic BP (-4.69 ± 2.24 mmHg, p = 0.04) was observed with co-administration of Rg3-KRG + AG relative to control at 12-weeks, which was characterized by a decrease in end-systolic pressure (-6.60 ± 2.5 mmHg, p = 0.01) and area under the systolic/diastolic BP curve (-132.80 ± 65.1, p = 0.04, 220.90 ± 91.1, p = 0.02, respectively). There was no significant change in reactive hyperemia index (0.09 ± 0.11, p = 0.44), PWV (-0.40 ± 0.28 %, p = 0.17), and other related pulse wave analysis components.

CONCLUSION

Co-administration of complementary ginseng species improved central systolic BP and components of pulse waveform without a direct effect on endothelial function, when added to background pharmacotherapy in individuals with diabetes. These data support potential utility of ginseng for modest blood pressure benefit to broaden its role in diabetes management.

Should Viscous Fiber Supplements Be Considered in Diabetes Control? Results From a Systematic Review and Meta-analysis of Randomized Controlled Trials

OBJECTIVE

Evidence from randomized controlled trials (RCTs) suggests that viscous dietary fiber may offer beneficial effects on glycemic control and, thus, an improved cardiovascular disease risk profile. Our purpose was to conduct a systematic review and meta-analysis of RCTs to synthesize the therapeutic effect of viscous fiber supplementation on glycemic control in type 2 diabetes.

RESEARCH DESIGN AND METHODS

MEDLINE, Embase, and Cochrane Central Register of Controlled Trials were searched through 15 June 2018. We included RCTs ≥3 weeks in duration that assessed the effects of viscous fiber on markers of glycemic control in type 2 diabetes. Two independent reviewers extracted data. Data were pooled using the generic inverse variance method and expressed as mean differences (MD) with 95% CIs. Heterogeneity was assessed (Cochran Q statistic) and quantified (I ² statistic). The Grading of Recommendations Assessment, Development, and Evaluation (GRADE) approach was used to evaluate the overall certainty of the evidence.

RESULTS

We identified 28 eligible trial comparisons (n = 1,394). Viscous fiber at a median dose of ∼13.1 g/day significantly reduced HbA_1c (MD -0.58% [95% CI -0.88, -0.28]; P = 0.0002), fasting blood glucose (MD -0.82 mmol/L [95% CI -1.32, -0.31]; P = 0.001), and HOMA-insulin resistance (IR) (MD -1.89 [95% CI -3.45, -0.33]; P = 0.02) compared with control and in addition to standard of care. The certainty of evidence was graded moderate for HbA_1c, fasting glucose, fasting insulin, and HOMA-IR and low for fructosamine.

CONCLUSIONS

Viscous fiber supplements improve conventional markers of glycemic control beyond usual care and should be considered in the management of type 2 diabetes.

Effect of psyllium (Plantago ovata) fiber on LDL cholesterol and alternative lipid targets, non-HDL cholesterol and apolipoprotein B: a systematic review and meta-analysis of randomized controlled trials

Background

Studies have identified viscous dietary fiber as potentially attenuating cholesterol, including psyllium, which reduces LDL cholesterol and thus may complement cardiovascular disease (CVD) treatment.

Objectives

The aims of this study were to update evidence on the effect of psyllium on LDL cholesterol and to provide an assessment of its impact on alternate markers: non-HDL cholesterol and apolipoprotein B (apoB).

Design

Medline, EMBASE, CINAHL, and the Cochrane Central Register of Controlled Trials were searched through 3 October 2017. Independent reviewers extracted relevant data and assessed risk of bias. We included randomized controlled trials with a duration of ≥3 wk that assessed the effect of psyllium on blood lipids in individuals with or without hypercholesterolemia. Data were pooled by using the generic inverse variance method with random-effects models and expressed as mean differences (MDs) with 95% CIs. Heterogeneity was assessed by Cochran's Q statistic and quantified by the I2 statistic. Overall quality of the evidence was assessed by using the GRADE (Grading of Recommendations Assessment, Development, and Evaluation) approach.

Results

We included 28 trials in our analysis (n = 1924). Supplementation of a median dose of ∼10.2 g psyllium significantly reduced LDL cholesterol (MD = -0.33 mmol/L; 95% CI: -0.38, -0.27 mmol/L; P < 0.00001), non-HDL cholesterol (MD = -0.39 mmol/L; 95% CI: -0.50, -0.27 mmol/L; P < 0.00001), and apoB (MD = -0.05 g/L; 95% CI: -0.08, -0.03 g/L; P < 0.0001). Effect estimates for LDL cholesterol and non-HDL cholesterol were graded as moderate quality on the basis of downgrades for inconsistency and graded as high quality for apoB.

Conclusion

Psyllium fiber effectively improves conventional and alternative lipids markers, potentially delaying the process of atherosclerosis-associated CVD risk in those with or without hypercholesterolemia. This trial is registered at www.clinicaltrials.gov as NCT03346733.

Acute effect of equicaloric meals varying in glycemic index and glycemic load on arterial stiffness and glycemia in healthy adults: a randomized crossover trial

BACKGROUND/OBJECTIVES

Dietary carbohydrate quality and quantity fluctuate but it is unknown which attribute takes precedence in vascular health preservation. We investigated all four permutations of glycemic index (GI) and glycemic load (GL) on acute vascular and glycemic responses.

SUBJECTS/METHODS

Twenty-one healthy adults were screened for this crossover trial. Seventeen (8 M:9 F; 26.7 ± 12.3 y; BMI 22.2 ± 2.8 kg/m²) entered randomization and completed the study, receiving four isocaloric meals, varying in GI and GL, in random order at least 3 days apart. The four meals included either chickpeas (GI = 28, GL = 14, 50 g available carbohydrates (CHO)), a small potato portion (GI = 85, GL = 14, CHO = 17 g), pasta (GI = 45, GL = 42, CHO = 94 g) or a large potato portion (GI = 85, GL = 42, CHO = 50 g) as the source of carbohydrate. Augmentation index (AIx) and central and peripheral blood pressure were measured fasting, 1, 2, 3, and 4 h post-consumption. Capillary blood glucose was analyzed fasting, 15, 30, 45, 60, 90, 120, 180, and 240 min.

RESULTS

A reduction in AIx from baseline was observed 4 h following the chickpeas (low GI-low GL) (p = 0.046). The incremental area under blood glucose curves were significantly higher 2 h post-consumption following high compared with low GL meals (p < 0.001). Despite doubling carbohydrates, there was no difference in glycemic response between the large potato (high GI-high GL) and the pasta (low GI-high GL) meals. No significant differences in AIx or blood pressure were seen between meals.

CONCLUSIONS

Low GI, low-carbohydrate meals may support a healthy vascular tone. Varying meal GI and GL results in different glycemic profiles, which are not necessarily predicted by carbohydrate content. Further investigations on cardiometabolic profiles to meals varying in GI and GL are warranted.

The effect of viscous soluble fiber on blood pressure: A systematic review and meta-analysis of randomized controlled trials

AIMS

Dietary fiber intake, especially viscous soluble fiber, has been established as a means to reduce cardiometabolic risk factors. Whether this is true for blood pressure remains controversial. A systematic review and meta-analysis of randomized controlled trials (RCTs) was conducted to investigate the effects of viscous soluble fiber supplementation on blood pressure and quantify the effect of individual fibers.

DATA SYNTHESIS

MEDLINE, Embase, and Cochrane databases were searched. We included RCTs of ≥4-weeks in duration assessing viscous fiber supplementation from five types: β-glucan from oats and barley, guar gum, konjac, pectin and psyllium, on systolic blood pressure (SBP) and diastolic blood pressure (DBP). Study data were pooled using the generic inverse variance method with random effects models and expressed as mean differences (MD) with 95% confidence intervals (CIs). Twenty-two (N = 1430) and twenty-one RCTs (N = 1343) were included in the final analysis for SBP and DBP, respectively. Viscous fiber reduced SBP (MD = -1.59 mmHg [95% CI: -2.72,-0.46]) and DBP (MD = -0.39 mmHg [95% CI: -0.76,-0.01]) at a median dose of 8.7 g/day (1.45-30 g/day) over a median follow-up of 7-weeks. Substantial heterogeneity in SBP (I² = 72%, P < 0.01) and DBP (I² = 67%, P < 0.01) analysis occurred. Within the five fiber types, SBP reductions were observed only for supplementation using psyllium fiber (MD = -2.39 mmHg [95% CI: -4.62,-0.17]).

CONCLUSION

Viscous soluble fiber has an overall lowering effect on SBP and DBP. Inclusion of viscous fiber to habitual diets may have additional value in reducing CVD risk via improvement in blood pressure.

PROTOCOL REGISTRATION

ClinicalTrials.gov identifier-NCT02670967.

A systematic review and meta-analysis of randomized controlled trials of the effect of konjac glucomannan, a viscous soluble fiber, on LDL cholesterol and the new lipid targets non-HDL cholesterol and apolipoprotein B

Background: Evidence from randomized controlled trials (RCTs) suggests the consumption of konjac glucomannan (KJM), a viscous soluble fiber, for improving LDL-cholesterol concentrations. It has also been suggested that the cholesterol-lowering potential of KJM may be greater than that of other fibers. However, trials have been relatively scarce and limited in sample size and duration, and the effect estimates have been inconsistent. The effect of KJM on new lipid targets of cardiovascular disease (CVD) risk is also unknown.Objective: This systematic review and meta-analysis aimed to assess the effect of KJM on LDL cholesterol, non-HDL cholesterol, and apolipoprotein B.Design: Medline, Embase, CINAHL, and the Cochrane Central databases were searched. We included RCTs with a follow-up of ≥3 wk that assessed the effect of KJM on LDL cholesterol, non-HDL cholesterol, or apolipoprotein B. Data were pooled by using the generic inverse-variance method with random-effects models and expressed as mean differences (MDs) with 95% CIs. Heterogeneity was assessed by the Cochran Q statistic and quantified by the I² statistic.Results: Twelve studies (n = 370), 8 in adults and 4 in children, met the inclusion criteria. KJM significantly lowered LDL cholesterol (MD: -0.35 mmol/L; 95% CI: -0.46, -0.25 mmol/L) and non-HDL cholesterol (MD: -0.32 mmol/L; 95% CI: -0.46, -0.19 mmol/L). Data from 6 trials suggested no impact of KJM on apolipoprotein B.Conclusions: Our findings support the intake of ∼3 g KJM/d for reductions in LDL cholesterol and non-HDL cholesterol of 10% and 7%, respectively. The information may be of interest to health agencies in crafting future dietary recommendations related to reduction in CVD risk. This study was registered at clinicaltrials.gov as NCT02068248.

Salba-chia (Salvia hispanica L.) in the treatment of overweight and obese patients with type 2 diabetes: A double-blind randomized controlled trial

BACKGROUND AND AIM

Preliminary findings indicate that consumption of Salba-chia (Salvia hispanica L.), an ancient seed, improves management of type 2 diabetes and suppresses appetite. The aim of this study was to assesse the effect of Salba-chia on body weight, visceral obesity and obesity-related risk factors in overweight and obese adults with type 2 diabetes.

METHODS

A double-blind, randomized, controlled trial with two parallel groups involved 77 overweight or obese patients with type 2 diabetes (HbA_1c: 6.5-8.0%; BMI: 25-40 kg/m²). Both groups followed a 6-month calorie-restricted diet; one group received 30 g/1000 kcal/day of Salba-chia, the other 36 g/1000 kcal/day of an oat bran-based control. Primary endpoint was change in body weight over 6-months. Secondary endpoints included changes in waist circumference, body composition, glycemic control, C-reactive protein, and obesity-related satiety hormones.

RESULTS

At 6-months, participants on Salba-chia had lost more weight than those on control (1.9 ± 0.5 kg and 0.3 ± 0.4 kg, respectively; P = 0.020), accompanied by a greater reduction in waist circumference (3.5 ± 0.7 cm and 1.1 ± 0.7 cm, respectively; P = 0.027). C-reactive protein was reduced by 1.1 ± 0.5 mg/L (39 ± 17%) on Salba-chia, compared to 0.2 ± 0.4 mg/L (7 ± 20%) on control (P = 0.045). Plasma adiponectin on the test intervention increased by 6.5 ± 0.7%, with no change observed on control (P = 0.022).

CONCLUSIONS

The results of this study, support the beneficial role of Salba-chia seeds in promoting weight loss and improvements of obesity related risk factors, while maintaining good glycemic control. Supplementation of Salba-chia may be a useful dietary addition to conventional therapy in the management of obesity in diabetes. REGISTRATION: clinicaltrials.gov identifier: NCT01403571.

Effect of Spinach, a High Dietary Nitrate Source, on Arterial Stiffness and Related Hemodynamic Measures: A Randomized, Controlled Trial in Healthy Adults

Diets rich in fruits and vegetables reduce risk of adverse cardiovascular events. However, the constituents responsible for this effect have not been well established. Lately, the attention has been brought to vegetables with high nitrate content with evidence that this might represent a source of vasoprotective nitric oxide. We hypothesized that short-term consumption of spinach, a vegetable having high dietary nitrate content, can affect the arterial waveform indicative of arterial stiffness, as well as central and peripheral blood pressure (BP). Using a placebo-controlled, crossover design, 27 healthy participants were randomly assigned to receive either a high-nitrate (spinach; 845 mg nitrate/day) or low-nitrate soup (asparagus; 0.6 mg nitrate/day) for 7 days with a 1-week washout period. On days 1 and 7, profiles of augmentation index, central, and brachial BP were obtained over 180 min post-consumption in 4 fasted visits. A postprandial reduction in augmentation index was observed at 180 min on high-nitrate compared to low-nitrate intervention (-6.54 ± 9.7% vs. -0.82 ± 8.0%, p = 0.01) on Day 1, and from baseline on Day 7 (-6.93 ± 8.7%, p < 0.001; high vs. low: -2.28 ± 12.5%, p = 0.35), suggesting that the nitrate intervention is not associated with the development of tolerance for at least 7 days of continued supplementation. High vs. low-nitrate intervention also reduced central systolic (-3.39 ± 5.6 mmHg, p = 0.004) and diastolic BP (-2.60 ± 5.8 mmHg, p = 0.028) and brachial systolic BP (-3.48 ± 7.4 mmHg, p = 0.022) at 180 min following 7-day supplementation only. These findings suggest that dietary nitrate from spinach may contribute to beneficial hemodynamic effects of vegetable-rich diets and highlights the potential of developing a targeted dietary approach in the management of elevated BP.

Carbohydrates and endothelial function: is a low-carbohydrate diet or a low-glycemic index diet favourable for vascular health?

Low-carbohydrate diets have become increasingly popular in both media and clinical research settings. Although they may improve some metabolic markers, their effects on arterial function remain unclear. Endothelial dysfunction is the well-established response to cardiovascular risk factors and a pivotal feature that precedes atherosclerotic diseases. It has been demonstrated that a high carbohydrate-induced hyperglycemia and subsequent oxidative stress acutely worsen the efficacy of the endothelial vasodilatory system. Thus, in theory, a carbohydrate restricted diet may preserve the integrity of the arterial system. This review attempts to provide insight on whether low-carbohydrate diets have a favorable or detrimental impact on vascular function, or it is perhaps the quality of carbohydrate that should direct dietary recommendations. Research to date suggests that diets low in carbohydrate amount may negatively impact vascular endothelial function. Conversely, it appears that maintaining recommended carbohydrate intake with utilization of low glycemic index foods generates a more favorable vascular profile. Understanding these relationships will aid in deciphering the diverging role of modulating quantity and quality of carbohydrates on cardiovascular risk.