OBESITY   

Minerva Medica 2009 June;100(3):237-245

Copyright © 2009 EDIZIONI MINERVA MEDICA

language: Italian

The biological activity of beta-glucans

Rondanelli M., Opizzi A., Monteferrario F.

Dipartimento di Scienze Sanitarie Applicate e Psicocomportamentali Sezione di Scienza dell’Alimentazione e Nutrizione Umana Facoltà di Medicina e Chirurgia Servizio Endocrino-Nutrizionale Azienda di Servizi alla Persona di Pavia Università degli Studi di Pavia, Pavia, Italia

This review summarizes the recent knowledge about the positive effect of betaglucans on human health. Beta-glucans are polysaccharides occurring in the bran of cereal grains (barley and oats and to a much lesser degree in rye and wheat, in amounts of about 7%, 5%, 2% and less than 1%, respectively), the cell wall of baker’s yeast, certain types of fungi, and many kinds of mushrooms. The differences between soluble and insoluble beta-glucans are significant in regards to application, mode of action, and overall biological activity. A growing body of science indicates that beta-glucans promote health in a number of important ways. Beta-glucans have been studied for their hypocholesterolemic effects; these mechanisms include: reducing the intestinal absorption of cholesterol and bile acids by binding to glucans; shifting the liver from cholesterol syntheses to bile acid production; and fermentation by intestinal bacteria to short-chain fatty acids, which are absorbed and inhibit hepatic cholesterol syntheses. Several studies have also shown that oat beta-glucans blunt the glycemic and insulin response. Moreover, beta-1,3-glucans improve the body’s immune system defense against foreign invaders by enhancing the ability of macrophages, neutrophils and natural killer cells to respond to and fight a wide range of challenges such as bacteria, viruses, fungi, and parasites. Finally, there is renewed interest in the potential usefulness of beta-glucan as a radioprotective drug for chemotherapy, radiation therapy and nuclear emergencies, particularly because glucan can be used not only as a treatment, but also as a prophylactic.