Viscosity rather than quantity of dietary fibre predicts cholesterol-lowering effect in healthy individuals.

The well-documented lipid-lowering effects of fibre may be related to its viscosity, a phenomenon that has been understudied, especially when fibre is given against the background of a typical North American (NA) diet. In this three-arm experiment, we compared the lipid-lowering effect of low-viscosity wheat bran (WB), medium-viscosity psyllium (PSY) and a high-viscosity viscous fibre blend (VFB), as part of a fibre intervention aimed at increasing fibre intake to recommended levels within the context of a NA diet in apparently healthy individuals. Using a randomised cross-over design, twenty-three participants (twelve males and eleven females; age 35 (SD 12) years; LDL-cholesterol (C) 2.9 (SEM 0.6) mmol/l) consuming a typical NA diet received a standard, fibre-enriched cereal, where approximately one-third of the fibre was either a low-viscosity (570 centipoise (cP)) WB, medium-viscosity (14,300 cP) PSY or a high-viscosity (136,300 cP) novel VFB, for 3 weeks separated by washout periods of ≥ 2 weeks. There were no differences among the treatments in the amount of food consumed, total dietary fibre intake, reported physical activity and body weight. Final intake of the WB, PSY and VFB was 10.8, 9.0 and 5.1 g, respectively. Reduction in LDL-C was greater with the VFB compared with the medium-viscosity PSY (-12.6 (SEM 3.5) %, P = 0.002) and low-viscosity WB (-14.6 (SEM 4.2) %, P = 0.003). The magnitude of LDL-C reduction showed a positive association with fibre apparent viscosity (r - 0.41, P = 0.001). Despite the smaller quantity consumed, the high-viscosity fibre lowered LDL-C to a greater extent than lower-viscosity fibres. These data support the inclusion of high-viscosity fibre in the diet to reduce plasma lipids among apparently healthy individuals consuming a typical NA diet.

Pharmacotherapy and weight-loss supplements for treatment of paediatric obesity.

Childhood obesity has become the most common paediatric disorder in the developed world. Treatment of obesity in children may include lifestyle interventions, pharmacotherapy and weight-loss supplements. The outcome of lifestyle interventions, which classically include dietary modifications, increased activity and behavioural modifications, remains insufficient and the adjuvant role of pharmacological agents has been proposed. Among the group of weight-loss medications, orlistat is the only pharmaceutical approved by the US FDA for the treatment of overweight and obese adolescents. The role of metformin needs to be established in larger studies and sibutramine remains an experimental product because of its potential adverse events. Weight-loss supplements lack sufficient data supporting their efficacy and safety, even in adults, and cannot be recommended at this time for adolescents. Preliminary data suggest that the use of fibre supplements, such as glucomannan, provides additional weight loss in individuals receiving a lifestyle intervention. No single approach will successfully treat obesity, and lifestyle modification presently remains the main pillar of any intervention aiming at decreasing bodyweight.

Safety considerations and potential interactions of vitamins: should vitamins be considered drugs?

OBJECTIVE: To examine adverse effects, adverse events, and potential interactions of vitamins in light of their current prevalence of use, and to discuss whether vitamins should be considered over-the-counter drugs or natural health products/dietary supplements. DATA SOURCES: We performed a MEDLINE/PubMed search, explored 4 online databases (Medline Plus, Drug Digest, Natural Medicine Comprehensive Database, and the database of the University of Maryland), and examined reference lists of included studies published from 1966 through October 2009. STUDY SELECTION AND DATA EXTRACTION: The studies were reviewed, with an emphasis on randomized controlled clinical trials. We included articles with the most clinically important information with regard to adverse events and interactions. DATA SYNTHESIS: Vitamins are used by over one third of the North American population. Vitamins have documented adverse effects and toxicities, and most have documented interactions with drugs. While some vitamins (biotin, pantothenic acid, riboflavin, thiamine, vitamin B(12), vitamin K) have minor and reversible adverse effects, others, such as fat-soluble vitamins (A, E, D), can cause serious adverse events. Two water-soluble vitamins, folic acid and niacin, can also have significant toxicities and adverse events. CONCLUSIONS: Our recommendation is that vitamins A, E, D, folic acid, and niacin should be categorized as over-the-counter medications. Labeling of vitamins, especially those intended for children and other vulnerable groups, should include information on possible toxicities, dosing, recommended upper intake limits, and concurrent use with other products. Vitamin A should be excluded from multivitamin supplements and food fortificants.

Supplementation of conventional therapy with the novel grain Salba (Salvia hispanica L.) improves major and emerging cardiovascular risk factors in type 2 diabetes: results of a randomized controlled trial.

OBJECTIVE: To determine whether addition of Salba (Salvia hispanica L.), a novel whole grain that is rich in fiber, alpha-linolenic acid (ALA), and minerals to conventional treatment is associated with improvement in major and emerging cardiovascular risk factors in individuals with type 2 diabetes. RESEARCH DESIGN AND METHODS: Using a single-blind cross-over design, subjects were randomly assigned to receive either 37 +/- 4 g/day of Salba or wheat bran for 12 weeks while maintaining their conventional diabetes therapies. Twenty well-controlled subjects with type 2 diabetes (11 men and 9 women, aged 64 +/- 8 years, BMI 28 +/- 4 kg/m2, and A1C 6.8 +/- 0.9%) completed the study. This study was set in the outpatient clinic of the Risk Factor Modification Center, St. Michael's Hospital, Toronto, Canada. RESULTS: Compared with the control treatment, Salba reduced systolic blood pressure (SBP) by 6.3 +/- 4 mmHg (P < 0.001), high-sensitivity C-reactive protein (hs-CRP) (mg/l) by 40 +/- 1.6% (P = 0.04), and vonWillebrand factor (vWF) by 21 +/- 0.3% (P = 0.03), with significant decreases in A1C and fibrinogen in relation to the Salba baseline but not with the control treatment. There were no changes in safety parameters including liver, kidney and hemostatic function, or body weight. Both plasma ALA and eicosapentaenoic polyunsaturated fatty acid levels were increased twofold (P < 0.05) while consuming Salba. CONCLUSIONS: Long-term supplementation with Salba attenuated a major cardiovascular risk factor (SBP) and emerging factors (hs-CRP and vWF) safely beyond conventional therapy, while maintaining good glycemic and lipid control in people with well-controlled type 2 diabetes.