Alcohol consumption and venous thromboembolism: friend or foe?

A light to moderate consumption of certain types of alcoholic beverages may exert a favorable effect on cardiovascular risk, but no conclusive information is available on the putative relationship between alcohol intake and the risk of venous thromboembolism (VTE). We performed an electronic search on Medline and Scopus, using the keywords "venous thromboembolism", "venous thrombosis" and "alcohol", to identify clinical studies linking alcohol intake and VTE risk. The literature search generated 16 studies, 4 of which are case-control, 1 cross-sectional and 11 prospective. Significant reduction of VTE associated with alcohol intake is observed in only 4/16 studies, and in all these the association is only meaningful for a moderate amount of alcohol (i.e., 2-4 glasses). Unlike these trials, two other studies observe that alcohol intake is associated with an increased risk of VTE, whereas the association is insignificant in the remainder. Binge drinking increases the VTE risk in one study but not in another. The consumption of beer is associated with a decreased VTE risk in one study but not in two others. We hence conclude that the relationship between intake of alcoholic beverages and increased or decreased risk of VTE is largely elusive.