Grapefruit helpt tegen overgewicht en diabetes*
Volgens een Canadese studie kan grapefruit effectief zijn in de strijd tegen
diabetes en overgewicht.
De kracht zou liggen in de bioactieve stof naringine, het bestanddeel van de grapefruit dat de vrucht zijn typische bittere smaak geeft. Deze bittere plantenvloeistof
die in het lichaam omgezet wordt in naringenine zou ervoor zorgen dat de lever vet gaat verbranden, in plaats van het op te slaan na een maaltijd. Bovendien zou de stof het insuline- en glucosegehalte reguleren.
Voor het onderzoek kregen twee groepen muizen een speciaal, Westers dieet om diabetes type 2 in de hand te werken. De ene groep muizen kregen
naringenine bij hun voeding, de andere groep niet.
In de groep die geen naringenine kreeg, ontwikkelden de muizen overgewicht en steeg het cholesterolgehalte en werden de muizen resistent voor insuline. De groep die wel naringenine kreeg, had hier geen last van.
De hoeveelheid die gebruikt werd is voor mensen redelijk hoog om gewoon uit de voeding te krijgen.
Study finds citrus-derived flavonoid prevents obesity
A flavonoid derived from citrus fruit has shown tremendous promise for preventing weight gain and other signs of metabolic syndrome which can lead to Type 2 Diabetes and increased risk of cardiovascular disease. The study, led by Murray Huff of the Robarts Research Institute at The University of Western Ontario looked at a flavonoid (plant-based bioactive molecule) called naringenin. The findings are published online in the journal Diabetes.
In the study one group of mice was fed a high-fat (western) diet to induce the symptoms of metabolic syndrome. A second group was fed the exact same diet and treated with naringenin. Naringenin corrected the elevations in triglyceride and cholesterol, prevented the development of insulin resistance and completely normalized glucose metabolism. The researchers found it worked by genetically reprogramming the liver to burn up excess fat, rather than store
it.
“Furthermore, the marked obesity that develops in these mice was completely prevented by naringenin,” says Huff, Director of the Vascular Biology Research Group at Robarts and Professor of Medicine and Biochemistry at the Schulich School of Medicine & Dentistry. “What was unique about the study was that the effects were independent of caloric intake, meaning the mice ate exactly the same amount of food and the same amount of fat. There was no suppression of appetite or decreased food intake, which are often the basis of strategies to reduce weight gain and its metabolic consequences.”
While grapefruit has long been linked to weight loss diets, the concentrations of the citrus-derived flavonoid being studied are at higher levels than you could get from dietary components. “We are examining the pharmacological properties of naringenin,” explains Huff. “The next step is to find out if naringenin prevents heart disease in animal models and to explore the feasibility of clinical trials to determine its safety and efficacy in humans.”
This study investigated naringenin’s preventative properties, but Huff is also investigating whether it can treat obesity and other existing metabolic problems. “These studies show naringenin, through its insulin-like properties, corrects many of the metabolic disturbances linked to insulin resistance and represents a promising therapeutic approach for metabolic
syndrome.”
The co-first authors on the paper are Erin Mulvihill and Emma Allister. The research was funded primarily by the Heart and Stroke Foundation of
Ontario.
Media contact: Kathy Wallis, Media Relations Officer, The University of Western Ontario, 519-661-2111 ext. 81136,
Kathy.wallis@schulich.uwo.ca (Juli
2009)
