Featured Research

from universities, journals, and other organizations

Alcohol Impairs Mental Performance More In The Young, Say Researchers

Date:
March 17, 1998
Source:
Duke University Medical Center
Summary:
A growing body of evidence on alcohol's effects shows that just one drink can impair learning and memory in both young animals and young humans, but has no memory effect on adults, according to researchers from Duke University Medical Center and the Durham VA Medical Center.

DURHAM, N.C. -- A growing body of evidence on alcohol's effects shows that just one drink can impair learning and memory in both young animals and young humans, but has no memory effect on adults, according to researchers from Duke University Medical Center and the Durham VA Medical Center.

Related Articles


The investigators said their research offers the first scientific evidence that alcohol has a markedly different effect depending on the age of the drinker. In addition, they said their studies provide the first hard evidence to support the ban on under-age drinking, which up until now has been based on moral, political or religious reasons.

"Historically, there has been no compelling reason to deter the youth of America from drinking, other than a moral or authoritarian message," said neuropsychologist Scott Swartzwelder, lead investigator of two new studies being published in April. "At least now we can back our message with scientific evidence showing that even occasional and moderate drinking could impair a young person's memory systems much more than an adult's."

Swartzwelder said the memory loss persisted as long as the subject was under the influence of alcohol, and that none of the information presented during that time was memorized. The long-term effects of chronic drinking are not known.

According to the new research, young animals respond differently to alcohol in three ways:

They suffer memory and learning impairments from as little as one drink, yet adults do not.

They develop more rapid tolerance to the drug than adults -- an incentive to drink more to get the same high.

They experience less sedation from the drug, meaning they can drink far more than adults before falling asleep. This puts adolescents at greater risk for a variety of dangerous outcomes, from memory and learning impairments to drunk-driving and impulsive sexual behavior, the researchers said.

The research is funded by the Alcoholic Beverage Medical Research Foundation, the National Institute on Alcoholism and Alcohol Abuse, and the U.S. Dept. of Veterans Affairs.

In one new study, to be published in the April issue of Alcoholism: Clinical and Experimental Research, Swartzwelder showed that just a single dose of alcohol prevented adolescent rats from learning how to swim to a platform in a water-filled maze, yet adult rats given the same dose easily learned and remembered the task. The amount of alcohol was not enough to sedate the rats or even affect their swimming abilities -- in the range of .08 percent blood alcohol level -- but it strongly impaired learning and memory in the adolescent rats.

This finding, which supports President Clinton's recent initiatives aimed at lowering the legal blood alcohol level in all states to .08 percent for drunk driving, was confirmed in preliminary human studies reported by Swartzwelder's team last year at the Research Society on Alcoholism meeting.

In that study, younger people given alcohol had a harder time recognizing words from a list read to them 20 minutes earlier, compared with older subjects who received an equivalent dose. While alcohol decreased the performance of all subjects, who ranged in age from 21 to 30, there was a strong correlation between their ages and their ability to learn and recognize the words after a dose of alcohol. Those under 25 performed markedly worse than those over the age of 30, he said.

"Quite simply, the younger the age, the worse they performed on the memory tests when given the equivalent of two drinks," he said. "If alcohol's effects varied that much within such a narrow age range, then there's a compelling reason to believe its effects are even stronger in adolescents and children."

Swartzwelder said obvious ethical and legal constraints have prevented him from studying alcohol's effects in people younger than 21, although he plans to continue his research in animals and, whenever ethically appropriate, in humans.

In his second new study, to be published in the April issue of the journal Alcohol, Swartzwelder showed that young rats developed tolerance to alcohol's temperature-lowering effects much more rapidly than adult animals. At first, all the animals given alcohol experienced a significant drop in body temperature -- an effect that occurs consistently among people and animals. But after several doses at two-day intervals, the adolescent animals had lost far less body temperature than the adults, indicating they had developed tolerance to one of alcohol's most basic effects.

The Alcohol study also showed that adolescents develop more rapid tolerance to the sedative effects of alcohol, indicating that the differences between adolescents and adults extend to multiple brain regions that control a variety of different functions.

In two 1995 rat studies, Swartzwelder showed precisely how alcohol impairs memory: it blocks the action of a specific nerve receptor in the hippocampus, the brain's center for learning and memory. When hippocampal "NMDA" receptors are inhibited, they cannot receive electrical signals from other nerve cells, thereby preventing the acquisition and storage of new information. Those findings were published in the May and December 1995 issues of Alcoholism: Clinical and Experimental Research.

"Young brains are built to learn," Swartzwelder said. "They have more NMDA receptors than adult brains, and their receptors are formulated with a different balance of proteins. This could account for why young brains experience such a dramatic decrease in memory-related activity when they're exposed to low doses of alcohol."


Story Source:

The above story is based on materials provided by Duke University Medical Center. Note: Materials may be edited for content and length.


Cite This Page:

Duke University Medical Center. "Alcohol Impairs Mental Performance More In The Young, Say Researchers." ScienceDaily. ScienceDaily, 17 March 1998. <www.sciencedaily.com/releases/1998/03/980317065941.htm>.
Duke University Medical Center. (1998, March 17). Alcohol Impairs Mental Performance More In The Young, Say Researchers. ScienceDaily. Retrieved December 21, 2014 from www.sciencedaily.com/releases/1998/03/980317065941.htm
Duke University Medical Center. "Alcohol Impairs Mental Performance More In The Young, Say Researchers." ScienceDaily. www.sciencedaily.com/releases/1998/03/980317065941.htm (accessed December 21, 2014).

Share This


More From ScienceDaily



More Mind & Brain News

Sunday, December 21, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Researchers Test Colombian Village With High Alzheimer's Rates

Researchers Test Colombian Village With High Alzheimer's Rates

AFP (Dec. 19, 2014) In Yarumal, a village in N. Colombia, Alzheimer's has ravaged a disproportionately large number of families. A genetic "curse" that may pave the way for research on how to treat the disease that claims a new victim every four seconds. Duration: 02:42 Video provided by AFP
Powered by NewsLook.com
Double-Amputee Becomes First To Move Two Prosthetic Arms With His Mind

Double-Amputee Becomes First To Move Two Prosthetic Arms With His Mind

Buzz60 (Dec. 19, 2014) A double-amputee makes history by becoming the first person to wear and operate two prosthetic arms using only his mind. Jen Markham has the story. Video provided by Buzz60
Powered by NewsLook.com
Prenatal Exposure To Pollution Might Increase Autism Risk

Prenatal Exposure To Pollution Might Increase Autism Risk

Newsy (Dec. 18, 2014) Harvard researchers found children whose mothers were exposed to high pollution levels in the third trimester were twice as likely to develop autism. Video provided by Newsy
Powered by NewsLook.com
Yoga Could Be As Beneficial For The Heart As Walking, Biking

Yoga Could Be As Beneficial For The Heart As Walking, Biking

Newsy (Dec. 17, 2014) Yoga can help your weight, blood pressure, cholesterol and heart just as much as biking and walking does, a new study suggests. Video provided by Newsy
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:

Strange & Offbeat Stories


Health & Medicine

Mind & Brain

Living & Well

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins