1.
Effect of pasta in the context of low-glycaemic index dietary patterns on body weight and markers of adiposity: a systematic review and meta-analysis of randomised controlled trials in adults.
Chiavaroli, L, Kendall, CWC, Braunstein, CR, Blanco Mejia, S, Leiter, LA, Jenkins, DJA, Sievenpiper, JL
BMJ open. 2018;(3):e019438
Abstract
OBJECTIVE Carbohydrate staples such as pasta have been implicated in the obesity epidemic. It is unclear whether pasta contributes to weight gain or like other low-glycaemic index (GI) foods contributes to weight loss. We synthesised the evidence of the effect of pasta on measures of adiposity. DESIGN Systematic review and meta-analysis using the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) approach. DATA SOURCES MEDLINE, Embase, CINAHL and the Cochrane Library were searched through 7 February 2017. ELIGIBILITY CRITERIA FOR SELECTING STUDIES We included randomised controlled trials ≥3 weeks assessing the effect of pasta alone or in the context of low-GI dietary patterns on measures of global (body weight, body mass index (BMI), body fat) and regional (waist circumference (WC), waist-to-hip ratio (WHR), sagittal abdominal diameter (SAD)) adiposity in adults. DATA EXTRACTION AND SYNTHESIS Two independent reviewers extracted data and assessed risk of bias. Data were pooled using the generic inverse-variance method and expressed as mean differences (MDs) with 95% CIs. Heterogeneity was assessed (Cochran Q statistic) and quantified (I2 statistic). GRADE assessed the certainty of the evidence. RESULTS We identified no trial comparisons of the effect of pasta alone and 32 trial comparisons (n=2448 participants) of the effect of pasta in the context of low-GI dietary patterns. Pasta in the context of low-GI dietary patterns significantly reduced body weight (MD=-0.63 kg; 95% CI -0.84 to -0.42 kg) and BMI (MD=-0.26 kg/m2; 95% CI -0.36 to -0.16 kg/m2) compared with higher-GI dietary patterns. There was no effect on other measures of adiposity. The certainty of the evidence was graded as moderate for body weight, BMI, WHR and SAD and low for WC and body fat. CONCLUSIONS Pasta in the context of low-GI dietary patterns does not adversely affect adiposity and even reduces body weight and BMI compared with higher-GI dietary patterns. Future trials should assess the effect of pasta in the context of other 'healthy' dietary patterns. TRIAL REGISTRATION NUMBER NCT02961088; Results.
2.
Co-administration of a konjac-based fibre blend and American ginseng (Panax quinquefolius L.) on glycaemic control and serum lipids in type 2 diabetes: a randomized controlled, cross-over clinical trial.
Jenkins, AL, Morgan, LM, Bishop, J, Jovanovski, E, Jenkins, DJA, Vuksan, V
European journal of nutrition. 2018;(6):2217-2225
Abstract
PURPOSE Use of polypharmacy in the treatment of diabetes is the norm; nonetheless, optimal control is often not achieved. Konjac-glucomannan-based fibre blend (KGB) and American ginseng (AG) have individually been shown to improve glycaemia and CVD risk factors in type 2 diabetes. The aim of this study was to determine whether co-administration of KGB and AG could improve diabetes control beyond conventional treatment. METHOD Thirty-nine participants with type 2 diabetes (6.5 > A1c < 8.4%) were enrolled between January 2002 and May 2003 at the Risk Factor Modification Centre at St Michaels Hospital in a randomized, placebo-controlled, crossover trial with each intervention lasting 12-weeks. Medications, diet and lifestyle were kept constant. Interventions consisted of 6 g of fibre from KGB together with 3 g of AG (KGB and AG) or wheat bran-based, fibre-matched control. Primary endpoint was the difference in HbA1c levels at week 12. RESULTS Thirty participants (18M:12F; age: 64 ± 7 years; BMI: 28 ± 5 kg/m2; HbA1c: 7.0 ± 1.0%) completed the study, and consumed 5.5 and 4.9 g/day of fibre from KGB and wheat bran control, respectively, and 2.7 g/day of AG. At week 12, HbA1c levels were 0.31% lower on the KGB and AG compared to control (p = 0.011). Mean (±SEM) plasma lipids decreased on the KGB and AG vs control by 8.3 ± 3.1% in LDL-C (p = 0.002), 7.5 ± 2.4% in non-HDL-C (p = 0.013), 5.7 ± 1.9% in total-C (p = 0.012), 4.1 ± 2.1% in total-C:HDL-C ratio (p = 0.042), 9.0 ± 2.3% in ApoB (p = 0.0005) and 14.6 ± 4.2% in ApoB:ApoA1 ratio (p = 0.049). CONCLUSIONS Co-administration of KGB and AG increases the effectiveness of conventional therapy through a moderate but clinically meaningful reduction in HbA1c and lipid concentrations over 12 weeks in patients with type 2 diabetes. CLINICAL TRIALS REGISTRATION NCT02806349 ( https://clinicaltrials.gov/ ).