Does The Latest Brain Study Vindicate The 21 Drinking Age? Well, Not Exactly.

There is a new brain study making the headlines these days.  This study examined postmortem brains of three groups of people:  1) 11 people with alcohol use disorders (AUD) who began drinking consistently before age 21, 2) 11 people with AUD who began drinking consistently after age 21, and 3) 22 people who did not have any AUD at all, though many of them drank at least somewhat.  And among the three groups, only for the early-onset AUD group were epigenetic changes related to the expression of brain-derived neurotrophic factor (BDNF) found, particularly in the amygdala, which is responsible for regulating emotions.  These changes are thought to lead to difficulty regulating emotions, problems with anxiety, and even be part of the pathophysiology of alcoholism itself.

So what does this really mean, exactly?  First of all, the researchers seem to have arbitrarily picked 21 as the dividing line between early-onset and late-onset AUD drinkers, and made no further distinction within the early-onset group (i.e., before 15, before 18, first drink, first drunkenness, first regular drinking, etc.).  Secondly, the study looked at a small sample size of people with alcohol-use disorders (think alcohol abuse/dependence, alcoholism, truly heavy, heavy drinking for many years or decades), who at the time of death averaged well over 10 standard drinks per day and over 100 drinks per week, over 30+ years.  Males were also overrepresented (in fact there were zero women in the early-onset AUD group), and the early-onset group drank significantly heavier then the late-onset group.  It is probably safe to say that these drinkers are NOT representative of the vast majority of those who drink before 21, and given how early the onset of early-onset AUD drinkers tends to be, it would also be safe to say that this early-onset AUD group largely began drinking well before 18, if not before 15.  And even among the late-onset AUD group, the relative lack of epigenetic changes certainly did NOT stop them from becoming alcoholics in any case.

Furthermore, there is no temporality to this non-longitudinal study, so we don't know whether or not these epigenetic changes were due to pre-existing vulnerability or perhaps the early use of other substances such as that now-infamous neurotoxin, nicotine. (Most of the study subjects were smokers, apparently, and about 90% of adult regular smokers typically begin smoking before age 18).

Thus, this study tells us NOTHING about the difference between people in general who begin drinking at 18 versus 21.  NOTHING.  Nor does it vindicate the ageist abomination that is the 21 drinking age.  And anyone who claims otherwise is being, shall we say, "economical with the truth".

Latest Brain Studies Demonstrate The Same Old Flaws

Potentially adding fuel to the fire of the drinking age debate is a new study of 18-20 year old first-year university students in Spain, that looked at the effects of so-called "binge" drinking on the brain. In this study, 95 students (42 "bingers", 53 controls) were given tests of attention and working memory, and their specific brain waves were monitored with electrodes. No statistically significant differences were observed between the two groups in terms of actual performance, but the electrophysiological test suggested that more attention was expended to complete a given task among the "binge" group, as well as other electrophysiological differences. This is a lot more nuanced and less certain than the media are implying, and hardly represents "dain bramage."

The biggest flaw in this study was the fact that there was no over-21 comparison group. So we simply cannot infer anything at all about age from this piece of research. Absolutely zilch. A better method would have been to have three groups: 15-17, 18-20, and 21-24 years of age. But no study that we know of meets this standard. This would help to settle the nagging question of whether or not it actually is worse to drink at 18 rather than 21. Or perhaps some people are afraid of the possibility that their rationale for keeping the drinking age at 21 would be debunked if such a comparison was done. As yet, there is essentially ZERO hard evidence that drinking at 18 is significantly worse than doing so at 21, ceteris paribus, but a plethora of evidence showing that excessive drinking is unhealthy at any age. To be fair, however, the purpose of the study was not to test the rationale for the drinking age, but rather the effects of alcohol on a particular segment of the population.

Other flaws included small sample size, and not enough information to determine whether the results are of any practical significance. The lack of behavioral performance differences between the two groups suggests that the answer is not very much, but still warrants more study before jumping to any conclusion either way. Subjects were only required to refrain from using alcohol or drugs for at least 12 hours, so acute and transient effects (such as hangover, which can last for up to 36 hours) cannot be ruled out. Also, this was a cross-sectional study, so we do not know whether or not the purported effects were acutally innate characteristics that predated (or even predisposed for) the "binge" drinking. Tobacco smoking was also not controlled for. In other words, this study is preliminary at best.

It is also interesting to note that the average age of onset of drinking in the "binge" group was 14, and 15 in the nonbinge group.

The reason this blog uses scare quotes on the word "binge" is by convention: we do not feel that the definiton used (6+ standard drinks on at least one occasion in the past month, at a pace of 3+ drinks per hour) was an adequate one. That was equivalent to about 4+ American drinks, and undercounting and underreporting can also confound the results as well. Given the small sample size, there could be a few students that drank much more than the others, and more than they led on, and skewed the results. Some could have been dishonest about alcohol use disorders, which were an exclusion criterion, and could also have skewed the results.

Another recent study, done on college students in Belgium, also found similar electrophysiological differences, but again no behavioral differences for some reason. In this study, there were no differences in alcohol consumption or electrophysiological results at baseline, but both changed significantly in the "binge" group when measured 9 months later, but not in the control group. However, we should keep in mind that the binge group averaged 12.5 units (about 9 American drinks) per binge session, and two such binge sessions per week, which is quite extreme. Number of (American) drinks per week averaged a whopping 35 units (25 American drinks) in the binge group, while the control group drank about one drink per week. And some participants drank as recently as three days before the tests as well, potentially conflating short and long term effects, though this was ostensibly controlled for. One good thing about this study, however, was that the sample size was significantly larger than the aforementioned one, and there was both a before test and and after test.

Still another study in 2007, this time of 21-25 year olds (you know, folks who are legally allowed to imbibe) who were self-identified heavy drinkers (more than 25 drinks per week), found that subtle brain changes are not exclusive to those under the magic age of 21.  The heavy drinkers did not exhibit significant neuropsychological test differences, but PET scans showed subtle differences.  Of course, this study did not gain nearly as much attention as the others previously mentioned.

Drinking ludicrous amounts of alcohol is dangerous, period.  Regardless of age.  That, if anything, should be the moral of the story. Keeping the drinking age at 21 only encourages such extremes, especially for college students.

We at 21 Debunked provide this for informational purposes only and do not in any way advocate drinking of any kind, underage or otherwise.