Researchers have identified the precise mechanisms by which binge drinking contributes to clogs in arteries that lead to heart attack and stroke. The study adds to a growing body of evidence that drinking patterns are just as much as a risk, if not more, for cardiovascular disease than the total amount consumed.

According to the National Institute on Alcohol Abuse and Alcoholism (NIAAA), going on a “binge” means having five or more drinks for men, and four or more drinks for women, in two hours.

Many studies suggest that an irregular pattern of heavy drinking doubles the risk for a fatal heart attack, even as moderate drinking has been shown to reduce risk of heart disease (the red wine effect).

About 65 percent of Americans drink alcohol, with 15 percent reporting binge patterns in a national survey of problem drinkers.

Alcoholic beverages contain ethanol, which is mostly converted into acetaldehyde once in the human system at “binge” levels, with the levels of acetaldehyde remaining high for many hours after the binge has ended.

The current study clarified for the first time that binge levels of acetaldehyde cause an important type of immune cell, the monocyte, to become better able to stick to blood vessel walls, an important step in initiating atherosclerosis .

Whey they arrive on the scene, monocytes send out tethers, like anchors that snag the vessel wall. Once the monocyte swings close to the wall on its tether, it can then roll along the wall, getting stickier and sticker until it sticks in place permanently. Without this step, a major part of the immune component of atherosclerosis could not get underway.

In the past, experts believed that atherosclerosis developed when too much cholesterol clogged arteries with fatty deposits called plaques. When blood vessels became completely blocked, heart attacks occurred. Now most believe that the reaction of the body's immune system, more than the build-up itself, creates heart attack risk. Vessel walls mistake fatty deposits for intruders, akin to bacteria, and call for help from the immune system. Among other cell types, monocytes arrive with the goal of preventing infection, but end up causing inflammation that drives blood vessel blockage.

“Factors like binge-drinking have been linked to increased risk for heart disease, and the newer inflammatory model is beginning to explain how,” said John Cullen, lead researcher. “One of our experiments found that acetaldehyde, at levels found in the blood after binge drinking, increased the number of monocytes that can adhere to cells lining blood vessels by 700 percent.”

Health psychologists argue that motivating people to stop binging depends upon their belief that it is harming them. Thus, the authors of the current study hope the results empower public health campaigns that discourage binge drinking.

Further studies are underway to confirm that these actions of acetaldehyde underlie, in part, the detrimental effects of binge drinking on cardiovascular disease.