Debunk-Tuesday – Does Alcohol Kill Brain Cells?

Every Tuesday I am going to address one specific myth, urban legend, conspiracy theory or piece of pseudo-science. This time it’s about the common conception, that alcohol will cause your brain cells to die.

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A student’s life

When I had my first biopsychology seminar a few years ago, the docent gained for a short moment some impressive fame as she told us, that it is indeed a common misconception that alcohol causes your brain cells to die.
Imagine all of us students thinking “AAAYYYEEE! Next day tequila party! We got this covered.”

Well, as I said: it was only a short moment of never-ending happiness. Although she maybe was right about her claim, she still warned us about the dangers associated with alcohol abuse. Damn it. Could have been such an amazing day.
Frankly, I have no idea, who came up first with the idea of dying brain cells caused by alcohol, but this was something, I heard trough every stage of my life. There is an incredibly amount of people who still believe this, and it seems like a good idea, to shed some scientific light onto this matter.

Before we start I need you to be aware of something:
There is quite a difference of how alcohol affects an adult brain in comparison to an adolescent one. Since we are, of course, all responsible adults who would never encourage children to drink alcohol I will not refer to them either.

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Life’s not fair

When I started my research for this article, I had this idea in mind which my docent told me back in the days.

“Alcohol doesn’t cause your brain cells to die.”

And so, at first, I wanted to show you the misconceptions about cell death in your brain caused by alcohol consumption. But, life’s not black and white and so is this issue.
There are, indeed, some studies which suggest moderate (!) alcohol consumption can be beneficial to your health. If you want to read more about it, I suggest you to check out this article by @lesshorrible.
But because I’m a grumpy guy, I am here to make you feel guilty and miserable with every ounce of alcohol you drink. Take this!

Jokes aside, let’s dig deeper into the neurotoxicity of alcohol abuse.
As you probably have noticed by now, I am consistently speaking of “alcohol abuse” and not just “having a drink”. This is mainly due to the famous statement made by Paracelsus a couple of hundred years ago:

Sola dosis facit venenum.

Thus, the more you are exposed to a certain substance, the likelier it becomes that you will suffer some kind intoxication and related damages. Dawson et al. (2005) (1) are defining a risky drinking pattern for men (more than 14 drinks a week / more than four a day at least once a month) and for women (seven drinks a week / more than three a day). So, if you happen to see some similarities to your own behaviour it might be a good idea to consider changing it.

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Let's kill some neurons

Your brain is an amazing little thing. It contains about one trillion nerve cells (neurons) which are responsible for thoughts, decisions, mood, attention and so on. Every one of these neurons is supported by ten other cells, so-called glia cells. Both types can be damaged by chronic alcohol abuse (2).

If you start to chronically abuse alcohol there are some severe consequences quite likely to happen. First, it starts with moderate deficits (mood, behaviour, decision-making) but can lead to such extreme conditions like the Wernicke-Korsakoff syndrome (3). The first one is a quite unpleasant state which includes confusion, disordered gait and visual abnormalities caused by a lack of thiamine, while the latter is characterized by anterograde amnesia (you are not able to obtain new information). No one wants to experience that.

But even without these extreme conditions, it seems to be evident, that your brain undergoes significant changes during chronic alcohol abuse. Harper and Kril (1993) (4) were able to show the enlargement of cerebral ventricles (cavities inside the brain containing cerebrospinal fluid) as well as sulci (furrows on the cerebrum’s surface) in most alcoholics. These enlargements represent a reduction of brain mass, which was proven in postmortem studies weighting the brains of alcoholics. The cause behind the reduced mass of the brain is most probably connected to a combination of neuronal loss as well as their reduction in size. You are able to fight this though, if you start to stay abstinent for at least one to five months. But don’t get too excited: dead neurons stay dead.

One of the most affected brain area is the frontal lobe of the cerebrum (responsible for initiation of motor activity, integration of behaviour, intellect and emotion) (Jernigan et al. 1991) (5). The reduction of both grey and white matter as well seems to happen to alcoholics. Compared to non-alcoholics there was a 22-percent reduction of neurons inside the superior frontal cortex and motor cortex (Harper et al. 1987) (6).

In addition to the general shrinking of brain regions, chronic alcohol abuse can lead to the loss of some nuclei (certain structured neurons). The most in-depth studies are about the cholinergic nuclei in the basal forebrain and as far as research can tell, this area is heavily affected by alcohol abuse as well (Arendt 1993) (7) and is involved in a lot of important physiologic functions. But not enough, other nuclei suffer significant cell loss as well, like the locus ceruleus (Arango et al. 1996) (8) and the raphe nuclei (Baker et al. 1996) (9). The first one is mainly involved in information processing and learning while the latter affects mood regulation, sleep, behaviour (like drinking alcohol) and thinking patterns.
All of them suffer from alcohol abuse and start to decrease. I told you, I’m here to ruin your day.

Another one? Sure.
Some animal studies were able to show, that long-term alcohol abuse is not always needed to damage your brain. Just a few days of intoxication can result in a neuronal loss in certain areas of your cerebral cortex (Collins et al. 1996) (10). Damn.

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Quick brain snack

So, there is no myth after all? Brain cells do indeed die from alcohol?
Well, yes and no.
Since there are definitely too many people drinking too much alcohol (damn you, mirror) it is important to be aware of the consequences.

You can indeed use alcohol to make yourself dumber (sometimes this can appear like an incredibly attractive option), but to achieve that you have to drink heavily and consistently. A few drinks here and there (few does not equal every day) will probably not hurt you (so much) and your brain has some amazing recovery capabilities.
But still, if you ever had the thought that you might drink too much – you are quite likely right about it. This does not mean, that you have a chronic drinking problem but to reconsider your habits a bit.
I am not the one, who is going to tell you to live your life perfectly sober all the time, but you should always be aware of the consequences, if you choose to have a few more drinks.

Stay responsible and you will be alright. Ignore it, intoxicate yourself over and over again and you will at some point realize (or maybe not, because you are too dumb by then):
Dead neurons stay dead.
(I’m so much fun at parties.)

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Feel always free to discuss my ideas and share your own thoughts
about the things I’m writing about. Nobody is omniscient and if we all
walk away a bit smarter than before, we’ll have achieved a lot.
Thanks for reading and stay healthy.
Ego

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Make sure, to check out #steemstem for more science related content.

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References

(1) Dawson, D. A., Grant, B. F., Stinson, F. S., & Zhou, Y. (2005). Effectiveness of the derived Alcohol Use Disorders Identification Test (AUDIT-C) in screening for alcohol use disorders and risk drinking in the US general population. Alcoholism: Clinical and Experimental Research, 29(5), 844–854.

(2) 10th Special Report to the U.S. Congress on Alcohol and Health

(3) https://en.wikipedia.org/wiki/Wernicke%E2%80%93Korsakoff_syndrome

(4) Harper, C.G., and Kril, J.J. Neuropathological changes in alcoholics. In: Hunt, W.A., and Nixon, S.J., eds. Alcohol-Induced Brain Damage. NIAAA Research Monograph No. 22. NIH Pub. No. 93-3549. Rockville, MD: National Institute on Alcohol Abuse and Alcoholism, 1993. pp. 39–70.

(5) Jernigan, T.L.; Butters, N.; DiTraglia, G.; Schafer, K.; Smith, T.; Irwin, M.; Grant, I.; Schuckit, M.; and Cermak, L.S. Reduced cerebral grey matter observed in alcoholics using magnetic resonance imaging. Alcohol Clin Exp Res 15(3):418–427, 1991.

(6) Harper, C.G.; Kril, J.J.; and Daly, J. Are we drinking our neurons away? BMJ 294(6571): 534–536, 1987.

(7) Arendt, T. The cholinergic deafferentation of the cerebral cortex induced by chronic consumption of alcohol: Reversal by cholinergic drugs and transplantation, In: Hunt, W.A., and Nixon, S.J., eds. Alcohol-Induced Brain Damage. NIAAA Research Monograph No. 22. NIH Pub. No. 93-3549. Rockville, MD: National Institute on Alcohol Abuse and Alcoholism, 1993. pp. 431–460.

(8) Arango, V.; Underwood, M.D.; Pauler, D.K.; Kass, R.E.; and Mann, J.J. Differential age-related loss of pigmented locus coeruleus neurons in suicides, alcoholics, and alcoholic suicides. Alcohol Clin Exp Res 20(7):1141–1147, 1996.

(9) Baker, K.G.; Halliday, G.M.; Kril, J.J.; and Harper, C.G. Chronic alcoholism in the absence of Wernicke-Korsakoff syndrome and cirrhosis does not result in the loss of serotonergic neurons from the median raphe nucleus. Metab Brain Dis 11(3):217–227, 1996.

(10) Collins, M.A.; Corso, T.D.; and Neafsey, E.J. Neuronal degeneration in rat cerebrocortical olfactory regions during subchronic “binge” intoxication with ethanol: Possible explanation for olfactory deficits in alcoholics. Alcohol Clin Exp Res 20(2):284–292, 1996.