SATURDAY, Oct. 18, 2003 (HealthDayNews) -- Adolescent rodents that became inebriated suffered memory loss later in life and their bodies grew more slowly, according to a new study.
The findings may provide a glimpse into the hazards of binge drinking among human teenagers, one of the researchers says.
The memory loss in the rats, for instance, is not the equivalent of temporary forgetfulness after a "typical one-night, I-drank-too-much kind of thing" among humans, says study co-author Douglas B. Matthews, an associate professor of psychology at the University of Memphis. Instead, the memory loss appears to last into adulthood.
"This casts the human effect in a different light," Matthews adds.
Henry Wechsler, director of the Harvard School of Public Health College Alcohol Studies Program, agrees. "If drinking at these levels produces such long-term effects in humans as those demonstrated in mice, the lost abilities and potential can be devastating."
According to a recent federal report, the average American adult gets drunk 7.5 times per year. Men are responsible for an estimated 81 percent of drunken binges, defined as when a man has five drinks or a woman has four drinks over a short period of time.
Meanwhile, 44 percent of students at four-year colleges engage in binge drinking, as do about 30 percent of high school seniors, Wechsler says.
Researchers want to better understand the effects of extensive drinking upon adolescents, but the study of alcohol use in teens is riddled with ethical obstacles. "You wouldn't want to take a 15-year-old and have them drink to the point of passing out," Matthews notes.
So, the researchers turned to rats that are in their adolescent years. In the new study, researchers injected alcohol into the bloodstreams of rodents to the point where they passed out. The alcohol in their systems was equivalent to about a .40 blood-alcohol level in humans, five times above the legal driving level in most states and potentially dangerous.
Researchers later tested the rats after they became adults by checking their reactions after getting a smaller dose of alcohol.
The rats that had been exposed to high levels of alcohol did more poorly on mazes that require memory skills. "We don't know if (the effects) are permanent, but they seem to last for a while," Matthews says. "Something had probably been changed in an area of the brain that processes memory."
The rats also had stunted growth and liver problems.
The findings, which reflect those released earlier this year by North Carolina researchers, appear in the October issue of Alcoholism: Clinical & Experimental Research.
Scientists plan more research into the effects of alcohol on adolescent rats. It's important to understand the effects of alcohol levels that may more accurately reflect those in teenage humans, says Linda Patia Spear, a professor of psychology at Binghamton University, in a statement. Also, researchers need to examine whether the effects of alcohol are the same in adult rats, she adds.