Alcohol use is extremely common in today’s world, being socially acceptable at work functions, social gatherings, and celebrations of all kinds. Even though it is so common, the active ingredient ethanol is capable of a wide variety of negative side effects, both acute and chronic. These can take the form of physical damage to organs as well as neurological damage which can produce a variety of mental issues or disorders. These issues can be serious or even deadly and the risks increase exponentially the longer alcohol is used. The U.S. Department of Health and Human Services along with the USDA have gone so far as to recommend that if a person is not already drinking alcohol, that they do not begin for any reason¹.
Overview of Alcohol Effects
Alcohol is a strong central nervous system depressant which effects a wide range of body systems. Affected functions include the cardiovascular system, digestive system, sex drive and performance, as well as many sensory systems including vision, balance, memory, and higher reasoning. These effects are dose dependent meaning that the more alcohol someone drinks, stronger or more pronounced effects are produced. For example the memory effects are almost nonexistent at low doses, mild at medium doses, and extremely strong at high doses even to the point of total blackout. These effects can also be intensified if alcohol is mixed with other drugs, particularly other depressants.
The health risks are likewise dose dependent, meaning that small amounts of alcohol pose almost no risk, and can sometimes be beneficial when alcohol is used in extreme moderation. Let’s look at the heart for an example. Light drinking (2-3 drinks per week) can slightly lower your risk of heart disease and stroke, whereas heavy drinking (4+ drinks per day) can have the opposite effect and directly lead to a variety of potentially life-threatening heart conditions such as atrial fibrillation.
Short Term Effects of Alcohol Use
Once you take a drink, alcohol enters the blood by absorption through the stomach and the walls of the intestines. It then makes its way to the brain where the small molecular size of ethanol is such that it can easily pass through the blood-brain barrier and begin effecting neurotransmitter functions before being broken down by your body. The majority of alcohol metabolism occurs in the liver, where it is broken down into acetate for elimination from the body. This process involves alcohol first being broken down into acetaldehyde, an extremely toxic metabolite and a known carcinogen in humans. Acetaldehyde is present wherever alcohol metabolism takes place in the body, even in tissues other than the liver such as the gastrointestinal tract, pancreas, and even the brain.
The short term effects are mostly produced through alcohol induced changes in how the neurotransmitters GABA and glutamate work in the brain. GABA is a calming and inhibitory neurotransmitter, and alcohol use promotes GABA production, as well as increasing sensitivity to GABA. The other main avenue is through glutamate interactions. Glutamate produces the opposite effects that GABA does, and is an excitatory neurotransmitter and promotes stimulation. The brain’s sensitivity to glutamate is reduced, so it no longer has such a strong stimulant effect. This all works to slow the brain down substantially in small doses, and in larger doses can affect some deep neurological systems. Some of the immediate effects of alcohol consumption may include:
- Slowed Reflexes
- A Sense of Calm or Drowsiness
- Impaired Coordination and Balance
- Memory Difficulties
- Compromised Judgement
- Increased Sex Drive
- Slowed Heart Rate
- Depressed Breathing
- Slurring Speech
There are also short term risks associated with alcohol use. These are mostly physical, as the neurological symptoms can take time to manifest. These can be harmful and cause potentially dangerous issues, although they are rarely fatal on their own. Some of these short term risks include:
- Pylorospasm: Painful and involuntary gagging or vomiting.
- Gastritis: Inflammation of the stomach lining.
- Reflux: Stomach acid leaking into your esophagus.
- Mallory-Weiss Lesion: Tear at the stomach-esophagus connection.
The body can only metabolize at a certain rate, no matter the amount ingested. This is dependent on body mass, liver function, and genetic factors but for men is typically about 1 drink metabolized per hour. This means that if someone were to drink 4 drinks very quickly they would still be getting drunk long after they actually finished drinking. In this manner, the short term effects can intensify even after someone has stopped drinking or even gone to sleep¹.
Long Term Effects of Alcohol Use
While alcohol has fairly minor direct effects the longer it is regularly used, the more drastically the risks escalate. After about a month of daily use, the body will begin to buildup a tolerance to alcohol. This means that 2 things will begin to happen. First off, neurological changes known as “downregulation” will require someone to drink more alcohol to produce the same result. This means that neurotransmitters such as GABA and glutamate, as well as serotonin and dopamine will begin to have reduced efficiency and lowered levels. Likewise, metabolic changes occur which results in the body clearing alcohol from the blood more quickly, meaning that someone will feel drunk for a shorter time. Additionally, the faster clearance rate will result in someone having a more intense and rapid comedown from alcohol intoxication.
There are a variety of conditions that can worsen the normal damage done by alcohol and many of these are actually caused by chronic alcohol abuse. This acts like a snowball effect, getting worse and worse over time. For example, the liver takes the brunt of the impact for alcohol metabolism, and will subsequently have reduced function. This has a cascade effect on every other body system since the liver is responsible for clearing unwanted toxins from the blood and partially for synthesizing nutrients and proteins. Additionally, the body will preferentially metabolize alcohol calories over food calories, so even if someone eats while drinking they are getting less nutrition from the food as they would eating it without alcohol¹.
These changes along with continued damage to the liver, intestines, brain, kidneys, and heart can produce a wide variety of chronic health issues. Some of these can heal with abstinence, but others are permanent. Some of the common risks associated with long term alcohol use may include:
- Increased Susceptibility to Seizures: Glutamate excitotoxicity and repeated episodes of alcohol withdrawal are known to lower the seizure threshold, making seizures much more likely.
- Fibrosis: Moderate scarring of the liver and an indicator of progression to full-blown cirrhosis; can also cause portal hypertension.
- Cirrhosis: Significant scarring and severely reduced function of the liver due to alcohol-induced damage.
- Hepatic Steatosis: Buildup of fatty cells in your liver due to alcoholism, can cause liver swelling and reduced function.
- Alcoholic Hepatitis: Inflammation of the liver which can cause jaundice, ascites, fever, confusion, and fatigue.
- Chronic Pancreatitis: Inflammation of the pancreas due to alcohol-induced tissue damage; can lead to Type 2 Diabetes.
- Type 2 Diabetes: Insulin desensitization due to alcohol-induced blood sugar fluctuations and pancreas damage.
- Cardiomyopathy: Toughening, weakening, and distention of the heart muscles which impedes blood flow to the rest of the body; can lead to organ damage elsewhere in the body and may progress to congestive heart failure.
- Atrial Fibrillation: Irregular heartbeat which can cause low blood pressure, fatigue, blood clots, fluid buildup in extremities, and can lead to other heart conditions or stroke.
- Alcohol-Induced Hypertension: High blood pressure which can lead to heart attack, stroke, or aneurysm as well as kidney problems, vision loss, metabolic syndrome, memory problems and vascular dementia.
- Ischemic or Hemorrhagic Stroke: Lack of blood flow to the brain or bleeding in the brain resulting in brain damage or death; risk increased due to induced hypertension, cerebral embolism, reduced cerebral blood flow, and an increase in blood clotting factors.
- Peripheral Neuropathy: Loss of sensation, pain, and weakness typically in the extremities due to alcohol-induced nerve damage; can be chronic or even permanent.
- Alcoholic Dementia: A wide range of dementia-like conditions fit under this umbrella term, but most present symptoms such as impairment of strategic or “big picture” thinking, memory, and judgment.
A common neurological condition that results from chronic alcohol abuse is known as Wernicke-Korsakoff syndrome. Referred to colloquially as wet brain, this is actually 2 distinct conditions which are typically lumped together. Wernicke’s Encephalopathy is an acute (intense and sudden in onset) condition, while Korsakoff’s Psychosis is a chronic (long-onset and long-lasting) condition. They are both produced by the same deficiency of thiamine, but the duration or severity of this deficiency will determine if Wernicke’s will progress to Korsakoff’s.
- University of Oxford: Effect of Alcohol on Risk of Coronary Heart Disease and Stroke – Causality, Bias, or a Bit of Both?
- Journal of the American College of Cardiology: Alcohol Abuse and Cardiac Disease
- University of Nebraska Medical Center: Alcoholic Liver Disease – Pathogenesis and Current Management