Researchers found that consuming 14 drinks a week, averaging two a day, is actually beneficial for the heart, while 14 drinks over a weekend damages it.
And, in a surprise finding, they also claim that binge drinkers gain three times more weight than moderate drinkers and double that of non-drinkers.
The study is the first to provide concrete evidence of the benefit and harm of select drinking patterns.
Moderate drinking decreased atherosclerosis, a condition that hardens and narrows arteries leading to a heart attack or stroke, in mice.
However, binge drinking increased development of the disease.
“People need to consider not only how much alcohol they drink, but the way in which they are drinking it,” the Daily Mail quoted lead researcher Dr John Cullen, of the University of Rochester Medical Centre in New York, as saying.
“Scientists don’t yet understand how moderate alcohol consumption benefits cardiovascular health or how heavy drinking episodes hurt it.
“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,” Cullen said.
The National Institute On Alcohol Abuse And Alcoholism in the U.S. defines binge or ‘at-risk’ drinking as consuming more than four drinks on any day for men, and more than three drinks on any day for women.
Understanding how much alcohol is in a ‘standard’ drink is also critical.
Dr Kenneth Mukamal, of Harvard Medical School, studies the roles of dietary and lifestyle, particularly alcohol consumption, on the incidence of cardiovascular and neurovascular disease.
“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,” Dr Mukamal said.
“This certainly backs up widespread clinical guidelines that limit drinking to one drink daily for non-pregnant women and two drinks daily for men,” Mukamal said.
In the study, mice in the ‘daily-moderate’ group were fed ethanol equivalent to two drinks every day of the week.
Mice in the ‘weekend-binge’ group were given approximately seven drinks on two days of the week and mice in the control group were fed a non-alcoholic cornstarch mix.
All mice were put on an atherogenic diet - which Dr Cullen equates to a high-fat Western diet of fried food every day - to encourage the development of atherosclerosis, which forms when fatty deposits or plaque collect on the inner walls of the arteries, causing them to narrow.
Levels of LDL, or ‘bad’ cholesterol, plummeted 40 percent in the daily-moderate drinking mice, but rose 20 percent in the weekend-binge drinking mice, compared to the no-alcohol controls.
High levels of bad cholesterol increase the risk of heart disease, and earlier studies show that every 10 percent increase in LDL results in a 20 percent increase in atherosclerosis risk.
Surprisingly, levels of HDL, or ‘good’ cholesterol, went up in both the moderate and binge drinking groups, which Dr Cullen speculates is an acute or short-term effect.
The volume of plaque, as well as the accumulation of immune cells that promote inflammation and consequently contribute to the narrowing of arteries, decreased in the moderate mice compared to no-alcohol mice.
The opposite occurred in the binge-drinking mice.
Another unexpected finding was that the binge-drinking mice gained significantly more weight than the moderate and control mice.
Though all mice started at approximately the same weight and consumed similar amounts of food over the course of the study, the binge mice gained more than three times as much weight as the moderate mice and about twice as much weight as the control mice.
Building on this study, Dr Cullen is investigating genes that are turned on or off following moderate and binge drinking episodes to determine if they influence outcomes.
The study is published in the journal Atherosclerosis.