"Drinking Alcohol Damages Teenagers’ Brains"

by David J. Hanson, Ph. D.

Does drinking in adolescence harm brain development? Does consuming alcohol before age 21 cause permanent brain damage? Does underage drinking retard mental development?

Federal agencies warn us that:

“Research indicates that the human brain continues to develop into a person’s early twenties and that exposure of the developing brain to alcohol may have long-lasting effects on intellectual capabilities.” 1

“Exposing the brain to alcohol during this period (i.e, before age 21) may interrupt key processes of brain development” and “alcohol–induced brain damage may persist.” 2

“The brains and bodies of teens are still developing, and alcohol use can cause learning problems.” 3

Private interest and activist groups assert that:

“Drinking before the age of 21 can cause irreversible brain damage.” 4

“There is growing evidence to suggest that alcohol use prior to age 21 impairs crucial aspects of youthful brain development” 5

“alcohol can do long-term and irreversible damage to critical neurological development that is ongoing during the teen-age years and continues until age 20.” 6

Similarly, newspaper stories tell us:

“research indicates that the brain continues to develop until age 21, and that young brains can be irreversibly damaged by alcohol.” 7

Research “shows the human brain doesn't stop growing until about age 21 or 22, and that alcohol consumption can alter or retard that growth, including memory and test-taking ability.” 8

The evidence about teen drinking and potential brain damage comes from two sources.

(1) The first source of evidence is from lab rats that are typically given very large doses of alcohol. Large enough quantities of alcohol appear to cause brain impairment in young rats, especially if given over a long enough period of time. 9

Interestingly, at lower levels of consumption, the “adolescent” rats tend to be less susceptible to motor impairment 10 and also less easily sedated than are older rats. 11 The conclusions to be drawn from this for rats’ brains and alcohol isn’t clear.

A more serious problem is that rats aren’t humans and many if not most processes found in rats don’t apply at all to humans. For example, innumerable drugs cure diseases in rats but the vast majority of such drugs fail to do so in humans.

(2) The second source of evidence comes from humans. However, the humans who are studied are virtually always alcohol and/or drug dependent individuals. Not surprisingly, long-time alcohol abusers tend not to do as well at a variety of mental tasks as those who don’t abuse alcohol. 12

It appears that large enough quantities of alcohol can impair brain development in rats and that it can also do the same in humans. There’s no surprising news there.

These studies never deal with light or moderate alcohol consumption among young humans. However, “natural experiments” on drinking among young people have been going on for thousands of years around the world.

In many societies most people drink and they begin doing so in the home from a very early age. Examples familiar to most people include Italians, Jews, Greeks, Portuguese, French, Germans and Spaniards. 13 There is neither evidence or any reason to even suspect that members of these groups are brain impaired compared to those societies that do not permit young people to consume alcohol.

There appears to be absolutely no evidence whatsoever that the light or moderate consumption of alcohol by persons under the age of 21 causes any brain impairment or harm. Of course, that doesn’t justify breaking any laws.

Federally-funded research does suggest that teens who drink alcohol with their parents are less likely than others to have either consumed alcohol or abused it in recent weeks according to a nation-wide study of over 6,200 teenagers in 242 communities across the U.S.

Drinking alcohol with parents “may help teach them responsible drinking habits or extinguish some of the ‘novelty’ or ‘excitement’ of drinking” according to senior researcher Dr. Kristie Long Foley of the School of Medicine at Wake Forest University. Dr. Foley describes drinking with parents as a “protective” behavior. 14

Contrary to popular belief, drinking with parental approval is legal in many states across the country. Only seven states prohibit those under age 21 from drinking under all circumstances. 15

Needless to say, no one of any age should ever over-consume or abuse alcohol.

This website does not provide medical opinion or advice and none should be inferred.

References and Readings

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