Home Mental HealthHow Does Alcohol Affect The Brain And Central Nervous System

How Does Alcohol Affect The Brain And Central Nervous System

9 Minutes

Edited & medically reviewed by THE BALANCE Team

Fact checked

CONTENTS

Alcohol impairs brain cell communication and alters the action of brain neurochemicals. Even with short-term use, it slows brain function down and impairs judgment, memory, and motor skills.

Excessive alcohol use may result in long-term neurological damage that causes dementia, alcoholic neuropathy, and brain atrophy.

Alcohol use disorders are globally leading causes of disability and cause 3 million deaths each year due to harmful drinking, with important impacts on healthcare systems and societies.

How Alcohol Enters The Brain

When alcohol is consumed, it enters the bloodstream through the stomach and small intestines. Alcohol and its metabolites migrate through the bloodstream reaching essentially all parts of the body and the brain.

Alcohol is water-soluble as well as fat-soluble and it can permeate the blood-brain barrier (BBB) through which it can interact directly with its neurons. This is why alcohol’s impact on the brain and central nervous system (CNS) tends to be experienced immediately after one takes alcohol.

The Process Of Alcohol Absorption In The CNS

Alcohol acts on the CNS by interacting with neurotransmitter systems especially GABA and glutamate that form the basis of regulating the activity of the brain. Alcohol works synergistically with GABA to make brain activity even slower thus causing a sense of relaxation [1].

However, alcohol also suppresses the activity of the excitatory neurotransmitter glutamate reducing brain stimulatory activity at the same time. This two-fold action accounts for alcohol’s CNS depressant action slowing the functioning of the brain and impairing motor coordination.

Conditions That Affect The Impact Of Alcohol On The Brain

Alcohol affects the brain differently depending on the individual using alcohol. These factors include age, sex, body weight, and genetics. The rate at which alcohol is metabolized is slow in young people and the elderly, this makes them more vulnerable to alcohol.

Another factor is tolerance, which means the body slowly responds less to alcohol use over time, so frequent users may not feel the same effects they did when they first started drinking, but could still be doing long-term neurological damage to the body [1]. Furthermore, how often and how much alcohol is consumed greatly influences how much harm it will do to your CNS.

Overview Of The Major Areas Of The Brain

Different regions in the brain are impacted differently by alcohol. Some of the areas in the brain are the cerebral cortex, hippocampus, cerebellum, and hypothalamus together with the pituitary gland. Every region serves an important function including cognition, reasoning, memory formation, coordination, and hormonal control [2].

When alcohol gets to the brain, it affects the normal functioning of these regions leading to conspicuous deficits in behavior, memory, and motor functions.

Imbalance Of Neurochemicals

Neurotransmitter interference is perhaps the most elaborate way in which alcohol impacts the brain. GABA is an inhibitory neurotransmitter; an increase in GABA causes inhibition of brain response. Glutamate is an excitatory neurotransmitter; an increase in Glutamate will augment brain responses [1].

From that perspective, alcohol increases the GABA’s effect while inhibiting the release of glutamate and thus makes the brain less sensitive. This results in the side effects of alcohol that include; loss of control, drowsiness, and a decreased ability to reason.

Neurochemical research has also shown that chronic administration of alcohol could disrupt the equilibrium of these neurotransmitter systems thus causing long-term neurological problems.

The Role Of The Blood Brain Barrier In Effect Of Alcohol

Blood-brain barrier or BBB is simply a barrier that filters out most toxic components in the blood so that they do not penetrate the CNS.

However, with alcohol, it can pass this barrier promptly thus allowing it to have its way with the CNS. Due to this fact of passing swiftly through the blood-brain barrier, one can feel the effects of alcohol almost immediately.

Due to actual damage of the BBB with aging and chronic alcohol consumption, increased alcoholic penetration across the BBB occurs and, so the brain becomes even more susceptible to toxins and alcohol’s effect on the neurological system is more pronounced [2].

Cerebral Cortex: Disturbance In Thinking And Reasoning

The cerebral cortex is part of the brain that is in charge of decision-making, the ability to solve problems, and reason. This area of the brain is also inactivated by alcohol which makes the judgment worse and involves one in more risky affairs [3]. Thus, people under the influence of alcohol may take actions that they would not otherwise consider.

Hippocampus: Memory Formation And Blackouts

Alcohol inhibits the hippocampus – the part of the brain responsible for memory formation [1]. According to current research, drinking alcohol can negatively affect the capacity to store new memories and thus lead to conditions like memory blackouts where a person can wake up fully aware of surroundings with no capability to recall anything that happened before that.

It might have a long-term negative impact on the hippocampus due to which one is prone to lose memory and sometimes might suffer from weak memory formation.

Cerebellum: Effect On Coordination And Balance

The cerebellum is involved in the control of movement and balance. This area is affected by alcohol in such a way that it would portray all forms of transpires; stumbling, poor balance while walking, and slurred speech. When alcohol takes a toll for a long time, the sense of balance and coordination can be impaired permanently.

Hypothalamus And Pituitary Gland: Disturbance Of Hormones

The hypothalamus and the pituitary gland are involved in most of the body’s important hormonal mechanisms such as the stress response, thermoregulation, and sexual responses.

Alcohol may also affect moods and body temperatures. The use of alcohol for a long time has negative impacts on hormones that affect mental health and can lead to conditions like depression and anxiety.

Slows Down The CNS

An essential effect that is seen clearly after the consumption of alcohol is depression of CNS. Alcohol causes a decrease in brain function as well as increases the functional consequences of GABA and decreases the effects of glutamate [1]. This CNS depression causes sedation, poor coordination, and slowed reflexes and is most damaging when it concerns tasks such as driving or operating machinery.

Interacts With Neurotransmitters

The effects of alcohol on the nervous processes are based on its interaction with the brain neurotransmitters. The decrease in the GABA-mediated inhibitory influence and the inhibition of the excitatory Glutamate mechanisms lead to the slowing of transmitting and receiving brain signals. This interference can lead to a wide spectrum of reactions from simple relaxation to profound loss of voluntary movements.

Decreases Interaction Between Neurons

Alcohol over time has toxic effects on the synapses, the gaps between neurons through which messages pass within the brain. This is because reduced communication slows down thinking and is seen in memory and decision-making. In more extreme cases, this damage is likely to be permanent, therefore, adding to the other knock-on long-term neurological effects of alcohol consumption.

Affects Motor Coordination And Muscle Response

Alcohol’s influence on motor skills is directly related to the opinions about the cerebellum and the CNS in general. Defective coordination of voluntary muscles, weakness of extremities, and sluggishness of reflexes are characteristic toxic effects of alcohol. Chronic, protracted, sustained, and frequent periods of alcohol binge drinking result in permanent motor incoordination disability even after relinquishing alcohol drinking.

Feelings Of Euphoria Or Relaxation

One of the impacts that alcohol quickly exerts on the CNS is that of pleasure and something akin to being more comfortable, needing to hold back less. This is because alcohol impacts some neural transmitters like dopamine and GABA that are responsible for pleasure and awareness of stress.

In social situations, excessive self-disclosure is associated with increased extraversion but also, but it may also lead to overriding decision-making capability.

Slurry Speech And Drowsiness

Moderation in alcohol and drug consumption can be considered when relating to alcohol and drugs as CNS depressants: the higher the blood alcohol level the greater the CNS depressant effect.

Slurred speech, which indicates that an individual has taken alcohol, is an effect of alcohol on the motor control areas of the cerebellum and cerebral cortex. Lacking sufficient energy to change how you interact with your surroundings, delayed reflexes to confused senses also occur. In such situations, it is very dangerous to perform activities that involve coordination such as driving, handling heavy machinery, or carrying out activities requiring fine motor skills.

Dementia And Slow Reaction Times

One of the most major issues arising from alcohol is found in a reduction of the brain capacity when undertaking certain tasks or decision-making. Alcohol in any quantity slows down the brain, and this means that any quantity of alcohol is dangerous if driving has to be done.

This is because alcohol causes alteration of synaptic transmission in the brain especially in areas such as the cerebral cortex and hippocampus which translates to slower thought processing and memory.

Alcohol Poisoning Risks

In instances where there is a non-restricted use of alcohol, alcohol poisoning is likely to happen which is a medical condition. The CNS is depressed to an extent where simple things such as breathing and pulse and the ability to regulate one’s body temperature may be affected.

If left untreated, the results of alcohol poisoning may range from coma to irreversible brain damage or death. The effects on CNS are sudden onset and are much more severe when taken in large amounts within a short time interval.

Oxidative Stress And Inflammation In The Brain Tissue

Chronic consumption causes oxidative stress by the effects of free radicals on brain cells. Also, the liver converts alcohol into a dangerous chemical called acetaldehyde that causes oxidation.

In the long run, this oxidative damage results in inflammation of the brain affecting neuronal connection and can lead to permanent alcohol-related cerebral damage.

Neuronal Loss And Brain Shrinkage

There are long-term effects of alcohol; one of them is neuronal loss or any toxic effect alcohol has on neurons that causes the death of that neuron. It means that neuronal loss can cause brain atrophy, which in simple terms means a decrease in the brain’s size.

Research has revealed that alcoholics lose brain weight and volume in some regions like the cerebral cortex and cerebellum, and in some cases, these changes cannot be reversed.

Alcoholic Neuropathy: Peripheral Nerve Damage

Alcoholic neuropathy refers to a condition whereby the peripheral nerves are affected, and signs may include, tingling, numbness, and weakness in the extremities of the body. This is yet another neurological injury attributable to alcohol since alcohol is toxic to more than the CNS; it also impacts the peripheral nervous system (PNS). Prolonged use may even lead to permanent peripheral neuropathy that grossly affects the subject’s daily functioning.

The Brain’s Ability To Heal: Neuroplasticity Explained

The brain’s ability to reorganize itself by forming new neural connections is called neuroplasticity. The ability to adapt and recover is important to undo some of that damage from alcohol. After a person quits drinking, the brain begins to heal, restoring function to neurons that were previously damaged by alcohol, or replacing lost cells with new ones.

Recovery After Chronic Alcohol Use – Limitations

The brain can heal, but if it has been abused with alcohol for a very long period, whatever healing it can do, is going to have its limits. If atrophy or neuronal death in more vulnerable brain regions susceptible to alcohol damage (e.g., hippocampus and cerebellum) has occurred, these brain regions may not fully recover.

Furthermore, damage to cognitive function caused by Wernicke Korsakoff syndrome or alcohol-related dementia can also be permanent.

Early Intervention And Sobriety: Why It Matters

How much the brain can recover from alcohol-related damage is dependent on how early this occurs. The only way to prevent long-term neurological impairment from alcohol is to stop drinking alcohol or at least reduce consumption as soon as possible. In most cases, people who stop drinking earlier can regain brain function in different parts of the brain, including memory, decision-making, and motor function.

1. PubMed Central. AIMS Neuroscience. Effect of alcohol on the central nervous system to develop neurological disorder. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8222771/

2. Mayo Clinic Health System. Binge drinking and your body. https://www.mayoclinichealthsystem.org/hometown-health/speaking-of-health/does-drinking-alcohol-kill-brain-cells

3. Medline Plus. Alcohol. https://medlineplus.gov/alcohol.html

FAQs

How Does Alcohol Affect The Autonomic Nervous System, And How Could That Affect The Body?

Yes – alcohol does indeed affect the autonomic nervous system The autonomic nervous system regulates heart rate, blood pressure, and digestion. Continued use of alcohol can interfere with the body’s proper regulation of these functions and hence can result in complications such as heart disease or gastrointestinal problems.

Could Changes In Sensory Perception (Vision Or Hearing) Occur Due To Alcohol Use?

Alcohol can alter sensory perception. In the short term, your vision and hearing will slow down over time because communication between the brain and sensory organs will be slowed.
For instance, people’s vision may become blurry or their ability to recognize objects and gauge depth may be compromised; drinking impairs the ability to hear.
Over the long term, the prolonged use of alcohol can result in permanent optic nerve damage and affect eyesight or cause tinnitus, called ringing in the ears, because alcohol is toxic to the auditory nerve.

Why Do Some People Start To Tremble Or Shake After Drinking Alcohol?

Common symptoms of alcohol withdrawal are tremors or shaking, especially in the hands. With long-term use, the nervous system becomes dependent on alcohol to perform normal functions. Suddenly stopping drinking leaves the nervous system all of a sudden hyperactive because the dampening effect of alcohol is gone. The overactivity causes tremors, anxiety, and irritability, all symptoms of withdrawal. In rare cases, DTs coupled with possible seizures can occur.

HOW THE BALANCE CAN HELP WITH Mental Health

The Balance RehabClinic is a leading provider of luxury addiction and mental health treatment for affluent individuals and their families, offering a blend of innovative science and holistic methods with unparalleled individualised care.