Effects of Alcohol on Health

 

Effects of Alcohol on Health

Introduction

Alcohol (ethanol) is a psychoactive, dependence-producing substance found in alcoholic beverages such as beer, wine, whisky, rum, vodka, and brandy. It is one of the most widely consumed recreational drugs worldwide.

According to the World Health Organization (WHO):

• Alcohol contributes to more than 200 diseases and injury conditions.
• Approximately 2.6 million deaths globally were attributable to alcohol consumption in 2019.
• Alcohol is a leading cause of premature death among people aged 20–39 years.

1. What is Alcohol?

Definition

Alcohol refers to beverages containing ethanol (ethyl alcohol), produced by fermentation of carbohydrates by yeast.

Common Alcoholic Beverages

Beverage	Approximate Alcohol Content
Beer	4–8%
Wine	8–15%
Champagne	10–14%
Rum	35–50%
Whisky	40–50%
Vodka	40–50%
Brandy	35–60%

 

2. Alcohol as a Drug

Alcohol is classified as:

• CNS depressant
• Psychoactive substance
• Dependence-producing drug
• Toxic chemical

WHO describes alcohol as a toxic and psychoactive substance with dependence-producing properties.

3. Absorption and Metabolism of Alcohol

Absorption

Alcohol is rapidly absorbed from:

Stomach- Approximately 20%

Small Intestine- Approximately 80%

Factors increasing absorption:

• Empty stomach
• High alcohol concentration
• Carbonated beverages

Metabolism of Alcohol

About 90–95% of alcohol is metabolized in the liver.

Step 1

Ethanol → Acetaldehyde

Enzyme: Alcohol Dehydrogenase (ADH)

Step 2

Acetaldehyde → Acetate

Enzyme: Aldehyde Dehydrogenase (ALDH)

Step 3

Acetate → Carbon dioxide + Water + Energy

Importance of Acetaldehyde

Acetaldehyde is:

• Highly toxic
• Mutagenic
• Carcinogenic
• Responsible for many harmful effects of alcohol

4. Acute Effects of Alcohol

A. Effects on Brain

Low Dose Effects

Produces:

• Relaxation
• Mild euphoria
• Reduced anxiety
• Increased sociability

Moderate Dose Effects

Produces:

• Poor judgment
• Reduced concentration
• Delayed reaction time
• Slurred speech
• Loss of coordination

High Dose Effects

Produces:

• Confusion
• Loss of consciousness
• Respiratory depression
• Coma
• Death

B. Alcohol Intoxication

Symptoms

• Dizziness
• Vomiting
• Impaired balance
• Reduced reflexes
• Drowsiness

C. Alcohol Poisoning

Occurs when blood alcohol concentration becomes dangerously high.

Symptoms

• Slow breathing
• Cyanosis
• Hypothermia
• Seizures
• Coma

May cause death due to respiratory failure.

5. Alcohol Dependence and Addiction

Definition

Alcohol dependence is characterized by:

• Compulsive drinking
• Craving
• Tolerance
• Withdrawal symptoms

WHO estimates about 209 million people worldwide live with alcohol dependence.

Mechanism of Addiction

Alcohol stimulates dopamine release in reward pathways of the brain. Repeated exposure leads to:

·       Tolerance- Increasing amounts required for the same effect.

·       Dependence- Body adapts to alcohol presence.

·       Addiction- Loss of control over drinking behavior.

Withdrawal Symptoms

Mild Withdrawal

• Anxiety
• Tremors
• Sweating
• Insomnia
• Irritability

Severe Withdrawal

Delirium Tremens (DT)

Features:

• Hallucinations
• Severe confusion
• Fever
• Convulsions

It is a medical emergency.

6. Effects on the Liver

The liver is the primary organ affected by chronic alcohol use.

A. Fatty Liver (Hepatic Steatosis)

Earliest Stage- Fat accumulates inside hepatocytes.

Features

• Enlarged liver
• Often reversible

B. Alcoholic Hepatitis

Inflammation and destruction of liver cells.

Symptoms

• Fever
• Jaundice
• Hepatomegaly
• Abdominal pain

C. Liver Cirrhosis

Definition

Replacement of normal liver tissue by fibrous scar tissue.

Consequences

• Portal hypertension
• Ascites
• Liver failure
• Hepatic encephalopathy

Alcohol-related liver disease is one of the most important alcohol-attributable conditions worldwide.

7. Effects on Digestive System

Gastritis

Alcohol irritates gastric mucosa.

Symptoms:

• Nausea
• Vomiting
• Dyspepsia

Peptic Ulcer Disease

Alcohol:

• Damages protective mucosal barrier
• Delays ulcer healing

Pancreatitis

Acute Pancreatitis

Symptoms:

• Severe abdominal pain
• Vomiting

Chronic Pancreatitis

Leads to:

• Malabsorption
• Weight loss
• Diabetes mellitus

Alcoholic pancreatitis is considered one of the diseases directly attributable to alcohol use.

8. Effects on Cardiovascular System

Alcohol adversely affects the heart and blood vessels.

A. Hypertension

Chronic alcohol use causes:

• Increased blood pressure
• Increased vascular resistance

B. Alcoholic Cardiomyopathy

Definition

Weakening and enlargement of heart muscle.

Consequences

• Heart failure
• Reduced cardiac output

C. Arrhythmias

Alcohol increases risk of:

• Atrial fibrillation
• Irregular heartbeat

D. Stroke

Alcohol increases risk of:

• Ischemic stroke
• Hemorrhagic stroke

WHO estimated approximately 474,000 cardiovascular deaths attributable to alcohol in 2019.

9. Effects on Nervous System

Peripheral Neuropathy

Damage to peripheral nerves.

Symptoms:

• Tingling
• Numbness
• Weakness

Cerebellar Degeneration

Results in:

• Ataxia
• Poor coordination
• Unsteady gait

Cognitive Impairment

Long-term alcohol use causes:

• Memory deficits
• Reduced learning ability
• Poor executive function

10. Wernicke–Korsakoff Syndrome

Caused by: Vitamin B₁ (Thiamine) Deficiency, Common in chronic alcoholics.

Wernicke Encephalopathy

Symptoms:

• Confusion
• Ataxia
• Ophthalmoplegia

Korsakoff Psychosis

Symptoms:

• Severe memory loss
• Confabulation
• Learning impairment

11. Effects on Mental Health

Alcohol is strongly associated with:

Depression

• Increased incidence
• Worsening symptoms

Anxiety Disorders

May both cause and worsen anxiety.

Suicide

Alcohol significantly increases suicide risk.

Aggression

Associated with:

• Domestic violence
• Physical assault
• Criminal behavior

WHO recognizes alcohol as an important contributor to behavioral and mental health disorders.

12. Effects on Immune System

Alcohol suppresses immune function.

Consequences:

• Increased susceptibility to infections
• Delayed wound healing
• Reduced immune response

Increased Risk of

• Tuberculosis
• Pneumonia
• HIV-related complications

A causal relationship exists between alcohol use and tuberculosis as well as HIV disease progression.

13. Effects on Respiratory System

Alcohol can cause: Respiratory Depression Especially during overdose.

Increased Risk of

• Pneumonia
• Aspiration pneumonia
• Tuberculosis

14. Effects on Endocrine and Metabolic Systems

Hypoglycemia

Alcohol inhibits gluconeogenesis.

Symptoms:

• Weakness
• Sweating
• Confusion

Obesity

Alcohol provides: 1 gram Alcohol = 7 kcal

Excessive intake contributes to:

• Weight gain
• Central obesity

Diabetes

Heavy drinking may worsen:

• Insulin resistance
• Glycemic control

15. Effects on Reproductive System

Effects in Males

Hormonal Changes

• Reduced testosterone

Reproductive Effects

• Erectile dysfunction
• Reduced sperm count
• Reduced sperm motility
• Infertility

Effects in Females

• Menstrual irregularities
• Reduced fertility
• Hormonal disturbances

16. Alcohol During Pregnancy

Alcohol crosses the placenta freely. The fetal liver cannot adequately metabolize alcohol.

Fetal Alcohol Spectrum Disorders (FASD)

A group of birth defects caused by prenatal alcohol exposure.

Fetal Alcohol Syndrome (FAS)

Growth Defects

• Low birth weight
• Growth retardation

Facial Abnormalities

• Thin upper lip
• Small palpebral fissures
• Flattened midface

Neurological Problems

• Intellectual disability
• Learning difficulties
• Behavioral disorders

Alcohol use during pregnancy increases the risk of miscarriage, stillbirth, preterm birth, and fetal alcohol syndrome.

17. Alcohol and Cancer

Alcohol is classified as a Group 1 Carcinogen by the International Agency for Research on Cancer (IARC).

Mechanisms of Cancer Formation

Alcohol causes:

• DNA damage
• Oxidative stress
• Hormonal disturbances
• Acetaldehyde toxicity

Cancers Associated with Alcohol

Head and Neck

• Oral cancer
• Pharyngeal cancer
• Laryngeal cancer

Digestive Tract

• Esophageal cancer
• Colorectal cancer

Liver

• Hepatocellular carcinoma

Breast

• Breast cancer

Alcohol causes at least seven major types of cancer, and WHO states there is no safe level of alcohol consumption regarding cancer risk.

18. Social Consequences of Alcohol

Alcohol contributes to: Road Traffic Accidents- Impaired judgment and reflexes increase accident risk.

Violence

• Domestic violence
• Physical assault
• Sexual assault

Academic Problems

• Poor concentration
• Reduced productivity

Economic Problems

• Unemployment
• Financial instability

WHO reports substantial alcohol-related mortality from injuries, including road traffic accidents.

19. Benefits of Alcohol Abstinence

Short-Term Benefits

• Better sleep
• Improved concentration
• Better hydration
• Reduced anxiety

Long-Term Benefits

• Reduced cancer risk
• Reduced liver disease risk
• Improved heart health
• Better fertility
• Increased life expectancy

Acute vs Chronic Effects of Alcohol

Acute Effects	Chronic Effects
Euphoria	Addiction
Slurred speech	Liver cirrhosis
Poor coordination	Cardiomyopathy
Impaired judgment	Neuropathy
Alcohol poisoning	Pancreatitis
Accidents	Cancer

 

High-Yield Facts

·       Ethanol is the active component of alcoholic beverages.

·       Alcohol is a CNS depressant.

·       Acetaldehyde is the toxic intermediate metabolite.

·       Chronic alcoholism causes fatty liver, alcoholic hepatitis, and cirrhosis.

·       Alcohol dependence develops due to tolerance and addiction.

·       Wernicke–Korsakoff syndrome results from thiamine deficiency.

·       Alcohol is a Group 1 carcinogen.

·       Alcohol causes at least seven major cancers.

·       There is no completely safe level of alcohol consumption regarding cancer risk.

·       Alcohol use during pregnancy can cause fetal alcohol syndrome.

·       One gram of alcohol yields approximately 7 kcal.

One-Line Revision

"Alcohol is a psychoactive CNS depressant that affects nearly every organ system, causing addiction, liver cirrhosis, pancreatitis, cardiovascular disease, neurological damage, fetal abnormalities, cancers, accidents, and premature death." (World Health Organization)