A lifetime of heavy drinking can take its toll on the brain and body, but new research confirms what many have suspected — that brain damage can occur after only a few days of heavy drinking.
The animal study, published in the April issue of Alcoholism: Clinical & Experimental Research, finds that rats given large "bingeing" doses of alcohol every eight hours for four consecutive days experienced damage to their brains.
The area of the brain responsible for smell was damaged after only two days of heavy drinking and other regions were damaged after four days.
The new study counters a common belief that damage to brain cells occurs when the brain withdraws from long-term alcohol abuse, and not during alcohol consumption.
"We found that in fact the damage appeared to be predominantly occurring in this binge drinking model during the intoxication," says Fulton Crews, director of the center for alcohol studies at the University of North Carolina in Chapel Hill, and co-author of the study.
"This is a four-day model," added Crews. "If you went on a long weekend binge, you could do this."
The amount of alcohol given to the rats was roughly the equivalent of 10 drinks in a single occasion for humans, twice the amount commonly defined as binge drinking for men (it's four or more drinks for women).
Such binge drinking is relatively common — 15 percent of adults reported engaging in the practice at least once within the previous month, according to 1999 data from the National Center of Health Statistics.
The Damage of Drinking
A lot of what is known about human brains and alcohol has come from autopsy studies after someone dies following years of abuse.
"It's under those conditions that most of our knowledge about the damaging effects of alcohol has occurred. But it doesn't mean that it hasn't occurred earlier," says John Crabbe, director of the Portland Alcohol Research Center at Oregon Health Sciences University.
Some time ago, it was thought that brain damage associated with drinking was related to the poor nutritional intake of alcoholics — chronic drinking is related to a vitamin B1 deficiency and dementia.
"There is a small component that is nutrition, but there is a larger component that is alcohol," adds Crews.
Researchers have noted profound brain shrinkage associated with alcohol that can be seen on brain scans in living individuals, but the implications of this shrinkage are difficult to interpret.
"When a person stops drinking — even if they have been drinking for a long time — frequently a good bit of that shrinkage recedes," explains Crabbe.
Detecting Damage Sooner
The same type of brain shrinkage is associated with aging, and there seems to be no straightforward relationship between the degree of shrinkage and cognitive decline. Experts say that is why animal models are helpful. They allow researchers to better understand the basic mechanisms that may be at work in humans.
"We know humans have brain damage and we're trying to understand how that happens," explains Crews. "What these animal studies are doing are relating the brain damage to what we know about alcoholism in humans."
Additionally, experts say that advances in brain imaging techniques will allow further understanding of what is happening to the living human brain because of alcohol consumption.
"As [these imaging techniques] get better and better, we should be able to detect signs of changes in brain activity earlier and earlier," says Crabbe. "It's important to know how soon they start to develop."