Search

Purpose: Consumption of the algae spirulina (Arthrospira platensis or maxima) and wakame (Undaria pinnatifida) has been shown to lower LDL cholesterol concentrations in animals and humans, possibly due to the inhibition of intestinal cholesterol absorption. This mechanism, however, has never been investigated in humans. Therefore, we examined in non-hypercholesterolemic men and women the effects of spirulina and wakame consumption on serum markers for intestinal cholesterol absorption., Methods: Thirty-five healthy men and women without hypercholesterolemia consumed in a random order daily 4.8 g spirulina, wakame or placebo for 17 days, separated by 14-day washouts. After 17 days, serum cholesterol-standardized campesterol, sitosterol and cholestanol, and lathosterol concentrations were measured as markers for intestinal cholesterol absorption and cholesterol synthesis, respectively. Concentrations of serum total cholesterol, LDL and HDL cholesterol, triacylglycerol, and plasma glucose, and blood pressure were measured as well., Results: Compared with placebo, spirulina or wakame did not affect serum cholesterol-standardized campesterol (CI - 0.23 to 0.10 μmol/mmol, P = 0.435 and CI - 0.14 to 0.19 μmol/mmol, P = 0.729, respectively), sitosterol (P = 0.314 and P = 0.112), cholestanol (P = 0.610 and P = 0.809), or lathosterol (P = 0.388 and P = 0.102) concentrations. In addition, serum lipid and plasma glucose concentrations, and blood pressure were not changed., Conclusions: Daily consumption of 4.8 g spirulina or wakame for 17 days did not affect plasma markers for intestinal cholesterol absorption or cholesterol synthesis in non-hypercholesterolemic men and women. Serum lipid and glucose concentrations, and blood pressure were also not altered.

Backgound: Theobromine, a component of cocoa, may favorably affect conventional lipid-related cardiovascular risk markers, but effects on flow-mediated dilation (FMD) and other vascular function markers are not known., Objective: To evaluate the effects of 4-week theobromine consumption (500 mg/day) on fasting and postprandial vascular function markers., Design: In a randomized, double-blind crossover study, 44 apparently healthy overweight (N = 30) and obese (N = 14) men and women with low HDL-C concentrations, consumed daily 500 mg theobromine or placebo for 4 weeks. After 4 weeks, FMD, peripheral arterial tonometry (PAT), augmentation index (AIx), pulse wave velocity (PWV), blood pressure (BP) and retinal microvasculature measurements were performed. These measurements were carried out under fasting conditions and 2.5 h after a high-fat mixed meal challenge., Results: 4-week theobromine consumption did not change fasting vascular function markers, except for a decrease in central AIx (cAIx, - 1.7 pp, P = 0.037) and a trend towards smaller venular calibers (- 2 µm, P = 0.074). Consuming a high-fat mixed meal decreased FMD (0.89 pp, P = 0.002), reactive hyperemia index (RHI, - 0.30, P < 0.001), peripheral systolic BP (SBP, - 3 mmHg, P ≤ 0.001), peripheral diastolic BP (DBP, - 2 mmHg, P ≤ 0.001), central SBP (- 6 mmHg, P ≤ 0.001) and central DBP (- 2 mmHg, P ≤ 0.001), but increased heart rate (HR, 2 bpm, P < 0.001). Theobromine did not modify these postprandial effects, but increased postprandially the brachial artery diameter (0.03 cm, P = 0.015), and decreased the cAIx corrected for a HR of 75 (cAIx75, - 5.0 pp, P = 0.004) and peripheral AIx (pAIx, - 6.3 pp, P = 0.017)., Conclusion: Theobromine consumption did not improve fasting and postprandial endothelial function, but increased postprandial peripheral arterial diameters and decreased the AIx. These findings do not suggest that theobromine alone contributes to the proposed cardioprotective effects of cocoa. This trial was registered on clinicaltrials.gov under study number NCT02209025.

Background and Aim: Increasing energy expenditure is an effective strategy for the prevention of obesity. In this respect, Lycium barbarum (goji berry) is of interest, as it has been shown to increase postprandial oxygen consumption. Although this suggests that energy expenditure was also increased, energy expenditure and substrate oxidation can only be assessed accurately when both oxygen consumption and carbon dioxide production are measured. We therefore investigated the effects of a single dose of Lycium barbarum fruit on postprandial energy expenditure and substrate oxidation in a randomized, double-blind crossover trial. In addition, markers of lipid and glucose metabolism were measured., Methods: Seventeen healthy, overweight men received in a random order a meal containing 25 grams of dried Lycium barbarum fruit or a control meal matched for caloric content and macronutrient composition. Energy expenditure and the respiratory quotient were determined using indirect calorimetry before and up to 4 hours after meal intake. Blood was sampled before and after meal intake at regular intervals for analyses of plasma glucose, serum triacylglycerol, and free fatty acid concentrations., Results: Energy expenditure significantly increased after the Lycium barbarum and control meal, but no differences were found between the meals ( p =0.217). Postprandial changes in respiratory quotient ( p =0.719) and concentrations of glucose ( p =0.663), triacylglycerol ( p =0.391), and free fatty acids ( p =0.287) were also not affected by Lycium barbarum intake., Conclusions: A single dose of Lycium barbarum does not affect postprandial energy expenditure, substrate oxidation, and markers for lipid and glucose metabolism in healthy, overweight men.

Cold exposure may be a potential therapy for diabetes by increasing brown adipose tissue (BAT) mass and activity. Here we report that 10 d of cold acclimation (14-15 °C) increased peripheral insulin sensitivity by ∼43% in eight type 2 diabetes subjects. Basal skeletal muscle GLUT4 translocation markedly increased, without effects on insulin signaling or AMP-activated protein kinase (AMPK) activation and only a minor increase in BAT glucose uptake.