Alcohol Tolerance

What is Alcohol Tolerance?

Drinking alcohol interferes with many bodily functions and affects behavior. However, after long-term, chronic alcohol consumption, drinkers may develop tolerance to at least some of alcohol’s effects.

Alcohol tolerance occurs after consistent, continued alcohol consumption leads to a lesser effect. In other words, higher amounts of alcohol are necessary to produce the same effects.

The human body can adapt to increased alcohol use, leading to the rapid metabolism of alcohol. This means that those who consume alcohol more frequently may also appear less intoxicated than other people who have consumed a similar amount of alcohol.

Types of Alcohol Tolerance

There are various types of alcohol tolerance caused by different factors:

Low Alcohol Tolerance

Those who have a low alcohol tolerance tend to become drunk more easily than those with higher alcohol tolerance.

High Alcohol Tolerance

People with a high alcohol tolerance can consume a lot of alcohol without experiencing dramatic effects. However, this does not mean that they are dependent on alcohol.

Those dependent on alcohol may have a high tolerance following years of excessive drinking. They also start to crave alcohol when they do not have access to it.

Functional Tolerance

People develop tolerance when their brain functions alter to compensate for the disruption caused by alcohol consumption in their behavior and bodily functions. This adaption is known as functional tolerance.

Those who engage in heavy alcohol use display functional tolerance when they illustrate few apparent signs of intoxication. Others show clear signs of intoxication.

As the drinker does not experience any noticeable behavioral impairment due to drinking, tolerance may increase the consumption of alcohol. This can lead to physical dependence and alcohol-related organ damage.

An individual with functional tolerance may be able to perform specific tasks after drinking alcohol but will not be able to perform others. For example, a person may develop tolerance more quickly when performing a task requiring focus than when completing a task requiring eye-hand coordination. This could be taking a written test versus driving a car.

The rapid development of tolerance to unpleasant rather than pleasurable effects of alcohol could lead to increased alcohol consumption. This influences how much a person may drink.

There are also a few subtypes of functional tolerance, including: 

Acute Tolerance 

Tolerance to most of alcohol’s effects develop with time and with consistent drinking. However, tolerance can also occur within a single drinking session. This is called acute tolerance.

Acute tolerance means that alcohol-induced impairment is more significant when assessed soon after starting alcohol consumption than when measured later during the drinking session. This is even if the BAC is the same in both instances.

Environment-Dependent Tolerance

Alcohol tolerance developing over several drinking sessions can accelerate if alcohol is consistently consumed in the same environment. Or if the same cues accompany it, such as if someone drinks alcohol at the same table each day or with the same person. This is called environment-dependent tolerance.

Learned Tolerance

The development of alcohol tolerance can speed up by practicing a certain task after drinking alcohol. This is called learned tolerance, or behaviorally augmented tolerance.

Environment-Independent Tolerance

Excessive drinking can lead to the development of functional tolerance independent of environmental influences.

Metabolic Tolerance

Tolerance that develops from a quicker elimination of alcohol from the body is called metabolic tolerance. It occurs when a specific group of liver enzymes are activated following chronic drinking. These liver enzymes metabolize alcohol. 

Enzyme activation boosts alcohol degradation and reduces the time which alcohol is active in the body. This reduces the duration of alcohol’s intoxicating effects.

Why Do Some People Have a Higher Tolerance Than Others?

Gender and body weight influence how a person tolerates alcohol. Men can typically drink more than women before they display signs of intoxication. Larger people are also able to drink more than smaller people before they appear drunk.

Other biological factors are more complicated. Some scientists believe alcohol tolerance relates to the enzymes involved in metabolizing the alcohol. However, others think there is a varied effect of neurotransmission in the brain.

In the neurotransmitters, the theory is that those who have high alcohol tolerance may not receive signals telling the brain to stop drinking. 

For the role of enzymes, alcohol metabolism is a multi-step process. Most of the alcohol processed in the body is first metabolized by the enzyme ‘alcohol dehydrogenase’ to a compound called ‘acetaldehyde.’

Acetaldehyde is then metabolized by the enzyme ‘aldehyde dehydrogenase.’ Some individuals are deficient in aldehyde dehydrogenase, resulting in a buildup of acetaldehyde in the blood.

This can then lead to flushing of the skin. Symptoms commonly linked with a ‘hangover’ may worsen or increase. Those of Asian descent are more likely to have an enzyme deficiency. Beyond that, our brains and bodies typically adjust quickly to excessive drinking.

The Role of Genetics and Gender in Alcohol Tolerance

Gender and body weight determine how much alcohol you can tolerate. Men are typically able to drink more than women before feeling the effects of alcohol. The same could be said for larger people compared to smaller people.

Someone larger will have a lower blood alcohol concentration than someone smaller who drank the same amount.

Biological factors may include the enzymes involved in metabolizing alcohol or the differing effect on neurotransmitters in the brain. Some people also do not have enough aldehyde or dehydrogenase, which metabolizes alcohol.

This can lead to your skin being flushed or worsened hangover symptoms. Specific groups of people like Asians tend to have this enzyme deficiency.

Alcohol Tolerance vs. Alcohol Use Disorder 

Alcohol dependence occurs when an individual needs to drink to carry out their normal daily functions. While consuming excessive amounts of alcohol can be dangerous, drinking larger amounts of alcohol with fewer adverse effects than average drinkers does not mean someone is experiencing alcohol dependence.

Dependence occurs not when someone can handle large quantities of alcohol but when they need to drink a certain alcohol quantity. Otherwise, the drinker may experience withdrawal symptoms or be unable to carry out their usual daily functions and responsibilities.

Alcohol tolerance refers to when people need to drink more to satisfy cravings. However, even healthy social drinkers can increase their alcohol tolerance over years of responsible consumption.

Risks of Higher Alcohol Tolerance 

You may believe that not having alcohol interfere with your behavior and capabilities of functioning is positive. However, alcohol tolerance can lead to problems. 

Tolerance to the effects of alcohol can affect drinking behavior and consequences in various ways:

• Encourages greater alcohol consumption
• Contributes to alcohol dependence and substance use issues
• Causes organ damage
• Affects the conduction of tasks
• Contributes to the effectiveness of medications
• Enhances the toxicity of other drugs
• Contributes to the risk of alcoholism

Can High Alcohol Tolerance Lead to Alcoholism?

Yes, a high alcohol tolerance may contribute to the risk of alcoholism.

A healthcare provider may ask the following questions relating to the past year to check an individual’s symptoms for alcohol use disorder:

• Have you had times when you ended up drinking more or longer than intended?
• Have you wanted to reduce or stop drinking, or tried to, but could not?
• Have you spent a lot of time drinking or being sick following the after-effects of alcohol consumption?
• Have you wanted a drink so badly you could not think of anything else?
• Have you found that drinking, or being sick from drinking, led to alcohol-related problems?
• Have you continued to drink even though it was causing issues with your family and friends?
• Have you given up or reduced engaging in activities that were once important or interesting to you to drink?
• Have you gotten into situations during or following drinking that raised your chances of getting hurt?
• Have you continued to drink even though it made you feel depressed, anxious, or added to another health issue?
• Have you had to drink significantly more than you once did to achieve the effects you desire?
• Have you found that when the effects of alcohol were wearing off, you had withdrawal symptoms such as difficulty sleeping, shakiness, nausea, sweating, a racing heart, or a seizure?

Most people with an alcohol use disorder will benefit from treatment. Medical treatment options/resources for alcohol use disorder include medicines and behavioral therapies. For many individuals, using both types of treatment offers the best results.

How to Reset Your Alcohol Tolerance

If you have developed an alcohol tolerance that you would like to address, there are safe ways to lower it.

Firstly, it is a good idea to identify your goals. This is whether they are to reduce your alcohol consumption or to quit drinking altogether. 

Then you should evaluate your current level of alcohol consumption and how likely you are to experience withdrawal symptoms. Speaking with a health professional is best.

Suppose you have not developed an alcohol dependence and do not experience withdrawal symptoms when you reduce your drinking. In that case, it is safe to significantly lessen or completely cut all alcohol use. Try abstaining from alcohol for at least a month. This allows all alcohol to flush from your system entirely, and your tolerance should disappear.

At the end of this abstinence period, evaluate your goals surrounding drinking. Decide if you would like to stay abstinent for longer or begin drinking in moderation.