No abstract

Background: Studies suggest that honey has less influence on serum glucose concentrations than monosaccharides and disaccharides. Previous studies, however, have only analysed glucose metabolism. Methods: This study investigated the influence of two types of honey (rapeseed and acacia) on the serum levels of glucose, fructose, insulin and C-peptide values in healthy subjects. The results were compared with honey-comparable glucose-fructose solutions. All solutions contained 75 g of glucose and/or fructose. Results: We found significantly higher fructose serum levels with rapeseed honey after 2 h but no such differences for acacia honey. C-peptide levels were significantly higher after administration of both honeys after 1 and 2 h.

BackgroundThe amount and quality of dietary fatty acids can modulate the fat metabolism.ObjectiveThis dietary intervention is based on the different metabolic pathways of long-chain saturated fatty acids (LCFA), which are mostly stored in adipocytic triacylglycerols, medium-chain fatty acids (MCFA) which are preferentially available for hepatic mitochondrial β-oxidation and n-3 long-chain polyunsaturated fatty acids (n-3 LCPUFA) suggested to modulate fat oxidation and storage by stimulating the peroxisomal β-oxidation. Combined dietary MCFA and n-3 LCPUFA without LCFA may synergistically stimulate fatty acid oxidation resulting in blood lipid clearance and LCFA release from adipocytes.DesignIn a short term, parallel, randomized, double-blind trial effects on the fatty acid metabolism of 10 healthy volunteers (Body Mass Index 25–30) of a formula containing 72% MCFA and 22% n-3 LCPUFA without LCFA (intake: 1.500 kcal/day; fat: 55.5% of energy) were measured in comparison to an isoenergetic formula with equal fat amount and LCFA dominated lipid profile.ResultsThe plasma triacylglycerol (p < 0.1) and cholesterol (p < 0.05) content decreased in the test group. The n-3/n-6 LCPUFA (≥ C 20) ratio increased (p < 0.0001) after 4 days treatment. The LCFA content was similar in both groups despite missing LCFA in the test formula indicating LCFA release from adipocytes into the plasma. Both groups significantly reduced body weight considerably 4 kg (p < 0.01) and fat mass up to 50% of weight loss (p < 0.05).ConclusionCombined dietary 72% MCFA and 22% n-3 LCPUFA without LCFA stimulate the fatty acid oxidation and release from adipocytes without affecting any safety parameters measured.

Earlier biological investigations have shown that royal jelly has insulin-like activity. However, there have so far been no clinical trials to support these findings. The objective of the present study was to study the effect of royal jelly ingestion on the glucose metabolism of healthy humans. Twenty volunteers underwent the standardized oral glucose tolerance test (OGTT) and afterwards a second OGTT after ingestion of 20 g of royal jelly. Serum glucose levels after 2 hours and the area under the curve for glucose were significantly lower (P = .041) after royal jelly administration. Substances originating from the pharyngeal glands of the honey bee with insulin-like activity are likely to have caused this effect and may thus be, at least partially, responsible for the lowering impact of honey on blood glucose levels. The identification of the substances that seem to act even after passage through the human stomach could lead to the development of new concepts in diabetology.

Background Progranulin represents an adipokine putatively mediating insulin resistance and inflammation. Data in humans are sparse, and the source of circulating progranulin in obesity is unknown. Objectives Serum progranulin concentrations and subcutaneous (sc) as well as visceral (vis) adipose tissue (AT) progranulin expression were quantified in a large cohort of patients with obesity undergoing bariatric surgery (BS) (n = 153) or a low‐calorie diet (LCD) (n = 121). Cohorts and methods Paired serum and AT mRNA samples were obtained from patients with severe obesity undergoing BS (ROBS cohort; Research in Obesity and Bariatric Surgery). Serum progranulin was measured by ELISA in both cohorts, and AT mRNA expression was analysed by quantitative real‐time PCR in bariatric patients. Results There was no gender‐specific effect in serum progranulin or AT progranulin expression. Importantly, circulating progranulin was independent from adipose tissue gene expression in paired samples. sc AT progranulin expression was higher than in vis AT (P = 0.027), and there was a positive correlation between sc AT and vis AT gene expression (P < 0.001; r = +0.34). Serum progranulin strongly and rapidly increased after BS within 3 days and remained elevated up to 12 months. Serum progranulin was strongly correlated with serum CTRP‐3 levels. Conclusions The present study provides detailed progranulin gene expression data in sc and vis AT in a large, prospective and observational cohort of patients with severe obesity. Serum progranulin concentrations are not predicted by sc or vis AT progranulin gene expression. Thus, AT seems not to be the main source of circulating progranulin levels in obesity.