What Is Alcohol Tolerance?

Table of Contents (click to expand)

People who have a high tolerance for alcohol either have a genetic disposition or have developed it through years of heavy drinking. When someone has a high tolerance, they can drink more alcohol without feeling the same effects as someone with a low tolerance. The reason for this is that the body becomes used to the alcohol and compensates for it in different ways.

Have you ever seen someone who chugs down bottles of alcohol without showing the tiniest signs that they’re getting drunk? People who have this ‘magical’ ability to not get drunk after consuming a considerable amount of alcohol are often often dubbed as the ‘whales’ of the group, referencing the common saying that they ‘drink like a fish’.

But why does this actually happen? Why are some people better at handling relatively large doses of alcohol?

Alcohol Tolerance

When a drinker has too much too drink on a regular basis, gradually, his/her body develops a kind of tolerance to alcohol. In this context, tolerance means that after regular drinking, the consumption of a given amount of liquor produces fewer effects than it does for a casual or occasional drinker. In other words, you could say that an alcohol-tolerant person must consume more liquor to produce the same effect, or the same ‘high’, if you will.

Some People Are Better At Handling Alcohol

Some people are simply born with a low sensitivity to alcohol. In simple words, they possess the ability to go round after round of beers, but show minimal effects.

So, if you sit a person with low alcohol sensitivity (or an alcohol tolerant person) with someone who drinks only occasionally, then despite consuming the same amount of liquor (say, 4 glasses of wine each), the former would mostly be alright, while the latter would be stuttering, blabbering and spilling their deepest secrets.

It’s usually seen that people born into families with a history of alcoholism are more likely to be born with low alcohol sensitivity. Researchers have not been able to identify exactly why this happens, but it often does.

Some People Develop Alcohol Tolerance

There is also the other class of people who actually develop a tolerance towards alcohol by constantly drinking large amounts of it. It all comes down to the fact that the more you drink alcohol, the more your brain and body adjust to the rising doses of alcohol in your system. The upshot is that you need to drink even more to achieve the same ‘high’.

Also Read: Why Does Alcohol Affect Women More Than Men?

How Does The Body Develop Alcohol Tolerance?

The most important aspect of alcohol tolerance occurs in the brain.

The two main neurotransmitters in the brain that are relevant to this discussion are GABA (performs inhibitory functions) and glutamate (performs excitatory functions, i.e., the opposite of GABA).

Alcohol significantly increases the activity of the GABA system – it does some of that directly, while some of that is done by inhibiting glutamate activity. Now, the brain’s job is to maintain homeostasis (a self-regulating process by which biological systems tend to maintain stability while adjusting to external conditions), so that you don’t die.

The brain has to maintain a balance between the GABA and glutamate systems.

In a bid to do that, the brain upregulates (i.e., increases the activity of) the glutamate system to compensate for the increased activity of the GABA system. That’s one of the reasons why people who drink a lot can easily handle large doses of liquor… doses that could potentially kill others. This is because the brains of long-term alcoholics have made compensatory changes within the glutamate system.

Of course, this is a massive over-simplification of the entire process; in reality, there are many other factors involved that influence how someone develops an alcohol tolerance.

The liver also plays a role. As you may know already, the liver is responsible for the processing of alcohol in our bodies. Liver cells have an organelle known as the Smooth Endoplasmic Reticulum (SER), whose job it is to break down nasty substances, such as alcohol and drugs.

Endoplasmic Reticulum
Smooth Endoplasmic Reticulum (SER). (Photo credit : Wikimedia Commons)

When you drink a lot on a regular basis, the liver registers that it needs to process more than its usual quota of alcohol. Thus, in response, it drastically increases the surface area of cells’ SER (over a period of just a few days). This aids in processing a larger volume of alcohol.

If you ever find yourself in a medical laboratory and have a chance to see the liver cells of an alcoholic under a microscope, you will notice that the SER in their cells are much larger than in the liver cells of a non-alcoholic. That’s another reason why people become tolerant towards alcohol and will boldly match anyone drink for drink, any night of the week!

Also Read: Why Do We Make Poor Decisions When We Are Drunk?

How well do you understand the article above!

Can you answer a few questions based on the article you just read?

References (click to expand)
  1. (2017) Alcohol and Tolerance - Alcohol Alert No. 28-1995. The National Institute on Alcohol Abuse and Alcoholism
  2. Absorption Rate Factors // Rev. James E. McDonald, C.S.C. .... The University of Notre Dame du Lac
  3. ALCOHOL - www.gmu.edu:80
  4. The truth about tolerance: How much do you really know .... Consin–Mad
  5. Siegel, S. (2011, July). The Four-Loko Effect. Perspectives on Psychological Science. SAGE Publications.
Help us make this article better
About the Author

Ashish is a Science graduate (Bachelor of Science) from Punjabi University (India). He spearheads the content and editorial wing of ScienceABC and manages its official Youtube channel. He’s a Harry Potter fan and tries, in vain, to use spells and charms (Accio! [insert object name]) in real life to get things done. He totally gets why JRR Tolkien would create, from scratch, a language spoken by elves, and tries to bring the same passion in everything he does. A big admirer of Richard Feynman and Nikola Tesla, he obsesses over how thoroughly science dictates every aspect of life… in this universe, at least.