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.
This systematic review and meta-analysis aimed to assess the effect of KJM on LDL cholesterol, non-HDL cholesterol, and apolipoprotein B.
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
statistic.
Twelve studies (
= 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.
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.
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 I
) 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.clinicaltrials.gov; Unique identifier: NCT03394339.
The utility of the disposition index as a measure of β‐cell compensatory capacity rests on the established hyperbolic relationship between its component insulin secretion and sensitivity measures as ...derived from the intravenous glucose tolerance test (IVGTT). If one is to derive an analogous measure of β‐cell compensation from the oral glucose tolerance test (OGTT), it is thus necessary to first establish the existence of this hyperbolic relationship between OGTT‐based measures of insulin secretion and insulin sensitivity. In this context, we tested five OGTT‐based measures of secretion (insulinogenic index, Stumvoll first phase, Stumvoll second phase, ratio of total area‐under‐the‐insulin‐curve to area‐under‐the‐glucose‐curve (AUCins/gluc), and incremental AUCins/gluc) with two measures of sensitivity (Matsuda index and 1/Homeostasis Model of Assessment for insulin resistance (HOMA‐IR)). Using a model of log(secretion measure) = constant + β × log(sensitivity measure), a hyperbolic relationship can be established if β is approximately equal to −1, with 95% confidence interval (CI) excluding 0. In 277 women with normal glucose tolerance (NGT), the pairing of total AUCins/gluc and Matsuda index was the only combination that satisfied these criteria (β = −0.99, 95% CI (−1.66, −0.33)). This pairing also satisfied hyperbolic criteria in 53 women with impaired glucose tolerance (IGT) (β = −1.02, (−1.72, −0.32)). In a separate data set, this pairing yielded distinct hyperbolae for NGT (n = 245) (β = −0.99, (−1.67, −0.32)), IGT (n = 116) (β = −1.18, (−1.84, −0.53)), and diabetes (n = 43) (β = −1.37, (−2.46, −0.29)). Moreover, the product of AUCins/gluc and Matsuda index progressively decreased from NGT (212) to IGT (193) to diabetes (104) (P < 0.001), consistent with declining β‐cell function. In summary, a hyperbolic relationship can be demonstrated between OGTT‐derived AUCins/gluc and Matsuda index across a range of glucose tolerance. Based on these findings, the product of these two indices emerges as a potential OGTT‐based measure of β‐cell function.
Body mass index (BMI) is widely used to assess risk for cardiovascular disease and type 2 diabetes. Cut points for the classification of obesity (BMI >30 kg/m2) have been developed and validated ...among people of European descent. It is unknown whether these cut points are appropriate for non-European populations. We assessed the metabolic risk associated with BMI among South Asians, Chinese, Aboriginals, and Europeans.
We randomly sampled 1078 subjects from 4 ethnic groups (289 South Asians, 281 Chinese, 207 Aboriginals, and 301 Europeans) from 4 regions in Canada. Principal components factor analysis was used to derive underlying latent or "hidden" factors associated with 14 clinical and biochemical cardiometabolic markers. Ethnic-specific BMI cut points were derived for 3 cardiometabolic factors. Three primary latent factors emerged that accounted for 56% of the variation in markers of glucose metabolism, lipid metabolism, and blood pressure. For a given BMI, elevated levels of glucose- and lipid-related factors were more likely to be present in South Asians, Chinese, and Aboriginals compared with Europeans, and elevated levels of the blood pressure-related factor were more likely to be present among Chinese compared with Europeans. The cut point to define obesity, as defined by distribution of glucose and lipid factors, is lower by approximately 6 kg/m2 among non-European groups compared with Europeans.
Revisions may be warranted for BMI cut points to define obesity among South Asians, Chinese, and Aboriginals. Using these revised cut points would greatly increase the estimated burden of obesity-related metabolic disorders among non-European populations.
Despite the widespread use of ginseng in the management of diabetes, supporting evidence of its anti-hyperglycemic efficacy is limited, necessitating the need for evidence-based recommendations for ...the potential inclusion of ginseng in diabetes management.
To elucidate the effect of ginseng on glycemic control in a systematic review and meta-analysis of randomized controlled trials in people with and without diabetes.
MEDLINE, EMBASE, CINAHL and the Cochrane Library (through July 3, 2013).
Randomized controlled trials ≥30 days assessing the glycemic effects of ginseng in people with and without diabetes.
Relevant data were extracted by 2 independent reviewers. Discrepancies were resolved by consensus. The Heyland Methodological Quality Score and the Cochrane risk of bias tool were used to assess study quality and risk of bias respectively.
Sixteen trials were included, in which 16 fasting blood glucose (n = 770), 10 fasting plasma insulin (n = 349), 9 glycated hemoglobin (n = 264), and 7 homeostasis model assessment of insulin resistance (n = 305) comparisons were reported. Ginseng significantly reduced fasting blood glucose compared to control (MD = -0.31 mmol/L 95% CI: -0.59 to -0.03, P = 0.03). Although there was no significant effect on fasting plasma insulin, glycated hemoglobin, or homeostasis model assessment of insulin resistance, a priori subgroup analyses did show significant reductions in glycated hemoglobin in parallel compared to crossover trials (MD = 0.22% 95%CI: 0.06 to 0.37, P = 0.01).
Most trials were of short duration (67% trials<12wks), and included participants with a relatively good glycemic control (median HbA1c non-diabetes = 5.4% 2 trials; median HbA1c diabetes = 7.1% 7 trials).
Ginseng modestly yet significantly improved fasting blood glucose in people with and without diabetes. In order to address the uncertainty in our effect estimates and provide better assessments of ginseng's anti-diabetic efficacy, larger and longer randomized controlled trials using standardized ginseng preparations are warranted.
ClinicalTrials.gov NCT01841229.
Background
Dietary fiber has played a consistent role in weight management, with efficacy potentially attributed to increased viscous fiber consumption.
Purpose
To summarize the effects of viscous ...fiber on body weight and other anthropometric parameters, along with a calorie-deficient diet, through a systematic review and meta-analysis.
Methods
MEDLINE, EMBASE, and the Cochrane library were searched through July 24, 2019 for randomized controlled trials that assessed the effect of viscous fiber supplementation as part of a restricted calorie diet for ≥ 4 weeks relative to comparator diets. Data were pooled using the generic inverse-variance method with random-effects models and expressed as mean differences with 95% confidence intervals. Inter-study heterogeneity was assessed using Cochran’s
Q
and quantified with
I
2
. The Grading of Recommendations Assessment, Development, and Evaluation (GRADE) approach was used to evaluate the overall certainty of evidence.
Results
Findings from 15 studies (
n
= 1347) showed viscous fiber supplementation significantly decreased body weight (− 0.81 kg − 1.20, − 0.41;
p
< 0.0001), BMI (− 0.25 kg/m
2
− 0.46, − 0.05;
p
= 0.01), and body fat (− 1.39% − 2.61, − 0.17;
p
= 0.03), compared to control. No effect on waist circumference was found. The certainty of evidence was graded as “moderate” for body weight, BMI, and body fat based on downgrades for imprecision. Waist circumference was graded “low” for downgrades of inconsistency and imprecision.
Conclusion
Viscous fiber within a calorie-restricted diet significantly improved body weight and other markers of adiposity in overweight adults and those with additional risk factors for cardiovascular disease. This trial is registered at
www.clinicaltrials.gov
as NCT03257449.
Registration
ClinicalTrials.gov identifier: NCT03257449
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/m
2
; 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).
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.
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.
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.
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.
Clinicaltrials.gov identifier, NCT01578837;
Dear Editor, We read with interest the article published in the 16 February 2017 issue of The Journal, titled “Effect of Fibre Supplementation on Body Weight and Composition, Frequency of Eating and ...Dietary Choice in Overweight Individuals” by Solah VA et al. 1....
Ginsenoside Rg3, present in steamed ginseng (Panax Ginseng C.A. Meyer), is thought to be a potent modulator of vascular function. Our objective was to clinically evaluate acute effects of ginsenoside ...Rg3-enriched Korean red ginseng (Rg3-KRG) on measures of arterial stiffness and peripheral and central blood pressure (BP) parameters in healthy volunteers. Using a double-blind, randomized, crossover design, 23 individuals (9 males:14 females; age, 25 ± 2 years; body mass index, 22 ± 0.6 kg/m(2); systolic BP/diastolic BP, 113 ± 3/70 ± 2 mm Hg) were administered 400-mg Rg3-KRG extract or 400-mg wheat bran control on two separate visits with a 7-day washout period. Aortic augmentation index and central BP were measured using applanation tonometry by radial pulse wave analysis, and peripheral BP was evaluated oscillometrically. Measurements were taken at baseline and at 1, 2, and 3 hours after intervention. Compared with control, there were significant reductions in augmentation index (-4.3 ± 8.9%, P = .03), central (-4.8 ± 6.8 mm Hg, P = .01) and brachial mean arterial pressure (-4.4 ± 6.6 mm Hg, P = .01), central systolic (-5.0 ± 7.9 mm Hg, P = .01) and diastolic BP (-3.9 ± 6.6 mm Hg, P = .01), and brachial systolic (-4.4 ± 10.0 mm Hg, P = .048) and diastolic BP (-3.6 ± 6.4 mm Hg, P = .01) at 3 hours after intervention compared with control. This study is the first to demonstrate Rg3-KRG extract acutely lowers central and peripheral arterial pressures in healthy adults. Further clinical evaluation is desired to quantify efficacy in higher risk individuals and in long-term settings.
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