The relationship between alcohol consumption and health outcomes has a long history and has generated much research. Heavy drinking is detrimental to health; however, there is considerable and convincing evidence from both short-term biochemical experimental studies and observational studies of a beneficial association with certain health outcomes related to atherosclerotic processes. This beneficial association is most important for an average alcohol intake of one to two drinks per day. Important factors in determining the magnitude or direction of effects have been identified. Most criticisms based on methodological issues have been dismissed in recent years from an epidemiological point of view. However, important questions remain about the circumstances of such a beneficial association. The net effect of alcohol consumption on health outcomes is detrimental overall, owing to the negative effect of cancers, infectious disease, gastrointestinal diseases, alcohol-use disorders and injuries.