Honigeinlagerung

Der Wassergehalt des von den Pflanzen produzierten Nektars kann variieren. Um seine Konservierung in den Waben zu gewährleisten, darf er nicht gären. Deshalb wird er von den Bienen in Honig umgewandelt, indem sie seinen Wassergehalt senken und folglich den Zuckergehalt erhöhen. Dies verhindert die Entwicklung der Mikroorganismen. In der Dunkelheit des Bienenstocks ist es schwierig, den Herstellungsprozess des Honigs zu beobachten. Aus diesem Grund ist er auch nur wenig erforscht. Um die Umwandlung von Nektar in Honig zu untersuchen, haben wir die Technik der Tomographie eingesetzt. Sie ermöglicht es, den Zuckergehalt des eingelagerten Nektars sehr präzise zu messen, ohne den Bienenstock öffnen zu müssen und das Bienenvolk zu stören.

Polyphenol supplementation did not affect insulin sensitivity and fat deposition during one-month overfeeding in randomized placebo-controlled trials in men and in women.

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Segrestin B., Delage P., Nemeth A., Seyssel K., Disse E., Nazare J.-A., Lambert-Porcheron S., Meiller L., Sauvinet V., Chanon S., Simon C., Ratiney H., Beuf O., Pralong F., Yassin N.-a.-H., Boizot A., Gachet M., Pimentel K. J., Vidal H., Meugnier E., Vionnet N., Laville M.

Polyphenol supplementation did not affect insulin sensitivity and fat deposition during one-month overfeeding in randomized placebo-controlled trials in men and in women.

Frontiers in Nutrition, 9, 2022, 1-13.

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Résumé:

Two randomized placebo-controlled double-blind paralleled trials (42 men in Lyon, 19 women in Lausanne) were designed to test 2 g/day of a grape polyphenol extract during 31 days of high calorie-high fructose overfeeding. Hyperinsulinemic-euglycemic clamps and test meals with [1,1,1-13C3]-triolein were performed before and at the end of the intervention. Changes in body composition were assessed by dual-energy X-ray absorptiometry (DEXA). Fat volumes of the abdominal region and liver fat content were determined in men only, using 3D-magnetic resonance imaging (MRI) and magnetic resonance spectroscopy (MRS) at 3T. Adipocyte's size was measured in subcutaneous fat biopsies. Bodyweight and fat mass increased during overfeeding, in men and in women. While whole body insulin sensitivity did not change, homeostasis model assessment of insulin resistance (HOMA-IR) and the hepatic insulin resistance index (HIR) increased during overfeeding. Liver fat increased in men. However, grape polyphenol supplementation did not modify the metabolic and anthropometric parameters or counteract the changes during overfeeding, neither in men nor in women. Polyphenol intake was associated with a reduction in adipocyte size in women femoral fat. Grape polyphenol supplementation did not counteract the moderated metabolic alterations induced by one month of high calorie-high fructose overfeeding in men and women. The clinical trials are registered under the numbers NCT02145780 and NCT02225457 at ClinicalTrials.gov and available at https://clinicaltrials.gov/ct2/show/NCT02145780 and https://clinicaltrials.gov/ct2/show/NCT02225457.

ISSN Print 2296-861X
ISSN en ligne: 2296-861X
Digital Object Identifier (DOI): https://doi.org/10.3389/fnut.2022.854255
ID publication (Code web): 49288 Envoyer par e-mail

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Honigeinlagerung

Polyphenol supplementation did not affect insulin sensitivity and fat deposition during one-month overfeeding in randomized placebo-controlled trials in men and in women.