WEDNESDAY, Sept. 14 (HealthDay News) -- How often you consume alcohol may be more important than how much you consume in determining the risk of heart disease, new research in mice shows.

Researchers have found that binge drinking, defined as having seven drinks a day for two days in a week, may lead to weight gain and an increased risk for atherosclerosis or "hardening of the arteries" caused by fatty deposits on the walls of the arteries.

But the researchers from the University of Rochester Medical Center in New York found the opposite holds true for those who drink moderately on a regular basis. The study, performed in mice, revealed that drinking about two drinks every day may actually decrease the risk for heart disease.

"People need to consider not only how much alcohol they drink, but the way in which they are drinking it," lead study author John Cullen, research associate professor in the university's department of surgery, said in a university news release. "Research shows that people have yet to be convinced of the dangers of binge drinking to their health; we're hoping our work changes that."

In conducting the study, the researchers divided mice into three groups, including:

• A "daily-moderate" group, which was fed the ethanol equivalent of two drinks a day, seven days a week.
• A "weekend-binge" group, which was fed about seven drinks on two days of the week.
• A "control" group, which was fed a non-alcoholic cornstarch mix.

Additionally, all of the mice were given a high-fat diet -- simulating a typical "Western" diet with fried foods -- to increase the development of atherosclerosis.

The investigators found that levels of low-density lipoprotein (LDL) cholesterol -- known as "bad" cholesterol -- dropped 40 percent in the daily-moderate drinking mice, but jumped 20 percent in the weekend-binge-drinking mice, compared to the control group. The researchers noted that previous studies have shown a 10 percent increase in LDL causes a 20 percent increase in atherosclerosis risk.

The amount of plaque, as well as the number of immune cells that cause inflammation and clogged arteries, decreased in the daily-moderate mice. The opposite was true for the binge-drinking mice, the investigators found.

Meanwhile, despite similar starting weights and diets, the binge-drinking mice gained more than three times as much weight as the moderate mice and about twice as much weight as the control mice.

"Because obesity is also a risk factor for disease, binge drinking may have a strong negative impact on cardiovascular health," Lucy Liaw, research committee chair of the American Heart Association's Founders Affiliate, noted in the news release.

Based on the study's findings, the researchers suggested that health care professionals should ask how their patients drink when considering their risk for atherosclerosis.

"This evidence is very interesting because it supports a pattern of drinking that is emerging in clinical studies as both safe and seemingly most protective against heart disease -- frequent consumption of limited amounts of alcohol. This certainly backs up widespread clinical guidelines that limit drinking to one drink daily for non-pregnant women and two drinks daily for men," Dr. Kenneth Mukamal, associate professor of medicine at Harvard Medical School, stated in the news release.

The study authors pointed out that exactly how moderate amounts of alcohol benefit heart health -- or how heavy drinking hurts it -- remains unknown. They added, however, that the nearly 15 percent of Americans who binge drink (as estimated by the U.S. Centers for Disease Control and Prevention) should be aware of the risks to their health.

More information

The American Heart Association provides more information on alcohol and heart disease.