Cinetica dell'alcol etilico: fattori di variabilità in relazione agli effetti benefici e tossici

Wine and alcoholic beverages have a social and symbolic value which is ingrained in the Italian culture, despite the potential adverse effects induced by their consumption. This paper describes the kinetics of alcohol: absorption, distribution, and elimination of ethanol determine the time-course of alcohol concentrations in blood after intake of alcoholic beverages and the degree of exposure of organs to their effects. Most ethanol is eliminated by oxidation to acetaldehyde and acetate, catalysed principally by alcohol dehydrogenase (ADH) and aldehyde dehydrogenase (ALDH). Other ethanol oxidation pathways include catalase and cytochrome P450 2E1. Besides being a substrate of CYP2E1, ethanol is also a potent inducer of this enzyme. There is large inter- and intra-individual variability in alcohol metabolism, due to genetic and environmental factors. In particular, gender influences kinetics: in comparison with men, women reach higher concentrations of alcohol in blood after drinking equivalent amounts of alcohol. The difference is partly due to a smaller first-pass metabolism and a lower volume of distribution in women.Immoderate, acute or chronic consumption of alcohol is a well-recognized risk for many diseases. Recent epidemiological studies have given new insights into the public health significance of moderate alcohol consumption: there is evidence that moderate, regular intake of alcohol, particularly red wine, is associated with benefits. The data available in the literature are not conclusive and, in addition, do not adequately assess potential alcohol addiction, which is closely related to detrimental social behaviour and is a risk factor promoting various diseases. The consumption of alcohol cannot be viewed as a benefit for health: it is also important to stress the need for very moderate usage of alcoholic beverages, giving preference to ones containing small quantities of ethanol.