The relative risks of coronary heart disease (CHD) and overall mortality are reduced by moderate consumption of alcoholic beverages, particularly wine, which has major implications for public health. It appears likely that this beneficial effect of alcohol will soon be extended to some mental disorders. Although data on psychosis and mood and anxiety disorders are currently lacking, it appears that the relative risks of developing ischaemic stroke and Alzheimer's or vascular dementia are also lowered by moderate alcohol consumption. Such findings are still tentative because of the inherent methodological problems involved in population-based epidemiological studies, and it is unclear whether the benefit can be ascribed to alcohol itself or to other constituents specific to wine such as polyphenols. Plausible biological mechanisms have been advanced for the protective effect of alcohol and wine against CHD, many of which will also play roles in their protective actions against cerebrovascular disease and dementia. The specific antioxidant properties of wine polyphenols may be particularly important in preventing Alzheimer's disease. Because of the substantially unpredictable risk of progression to problem drinking and alcohol abuse, the most sensible advice to the general public is that heavy drinkers should drink less or not at all, that abstainers should not be indiscriminately encouraged to begin drinking for health reasons, and that light to moderate drinkers need not change their drinking habits for health reasons, except in exceptional circumstances.