Lead author Scott Ballinger exposed mice to smoky air in a laboratory enclosure and fed a liquid diet containing ethanol -- the intoxicating ingredient in alcohol. The mice exposed to smoke and alcohol had a an almost five-fold increase in artery lesions, compared to mice that breathed filtered air and ate a normal solid diet. Artery lesions are common among heavy smokers and a key sign of advancing cardiovascular disease, Ballinger said.

The study, published in the journal Free Radical Biology & Medicine, shows that exposure to cigarette smoke when combined with alcohol consumption caused the greatest degree of cardiovascular disease development compared to either action or exposure alone.

Blood-alcohol concentrations in the mice were equivalent to a 150-pound adult consuming two drinks per hour. Cigarette smoke exposure was similar to being in an automobile with a chain smoker with the windows closed.