Alcohol and Disease

Dr Bastiaan de Boer

School of Pathology and Laboratory Medicine

University of Western Australia

ALCOHOL AND DISEASE

Disclaimer: Yes, I drink

What is alcohol?

Alcohol is more correctly called ethyl alcohol

and also known as ethanol.

How is alcohol made?

• Fermenting various sources of sugar using

yeast or bacteria

– grains, fruits and vegetables

• turns the sugars into alcohol.

How is alcohol made?

Wine or Cider

from fruit

How is alcohol made?

Beer and spirits from cereals such as barley

and rye

Spirits also go through

distillation – where a

proportion of the water is

removed, leaving a

stronger concentration of

alcohol and flavour.

What is a “standard drink”?

A “standard” drink is an arbitrary unit of

measurement: 10g (12.5ml) of pure alcohol.

What is a “standard drink”?

What is meant by the terms:

• Alcoholism

– Physical dependence

– Tolerance

– Craving

– Loss of control

Dependence on alcohol to function normally

Withdrawal symptoms after stopping drinking

The need to drink greater amounts of alcohol to get “high”

A strong need or urge to drink

Not being able to stop once drinking has begun

What is meant by the terms: • Alcohol abuse

• Intoxication

• Alcohol poisoning

• Binge drinking

• Withdrawal

excitement or dulling of the senses

a dangerously high concentration of alcohol likely to to

induce coma or respiratory depression

drinking heavily on one occasion or continuously over a

period of time

Symptoms such as nausea, sweating, shakiness and

anxiety after stopping drinking (physical dependence).

a pattern of drinking that results in a recurring problem

Do you drink – yes or no?

What are your reasons?

Do you drink? – YES

• Socialise with friends

• Have fun or celebrate

• Relax

• Overcome social awkwardness

• Forget worries or problems

• Experiment

• Relieve boredom

• Because I like the taste

• It’s an important part of my

culture

• Peer pressure

• Decreases your risk of

atherosclerosis

Do you drink? – No

• I do not like the taste

• I do not like the feeling

• My parents tell me not to

• I have had a bad experience

• It is against my religion

• I socialize with people who do

not drink

• I do not have the enzyme

alcohol dehydrogenase

What happens to alcohol when you drink it?

Absorption

• Alcohol enters the blood stream within

minutes of consumption

• It is absorbed unchanged

• The small intestine absorbs much more

alcohol than the stomach

• Peak alcohol levels are reached 30 to 60

minutes after someone stops drinking

Distribution

• Alcohol is distributed throughout all of the

water-containing components of the body

• It distributes rapidly and thoroughly

• The less a person weighs, the smaller the

water content and the more he or she will

be affected

Distribution

• Fat contains less water than muscle so

those with a higher percentage of fat will

be more affected

• On average men are 68% water, woman

are 55% water therefore women are more

affected.

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Elimination

• Approx. 95 % is metabolized in the liver

• A person metabolizes one standard drink

(10g alcohol) per hour

• It is excreted in urine, tears, sweat, semen,

and saliva

• Alcohol evaporates from the blood into the

lungs and is excreted in breath

– This can be measured in a breath sample

• Metabolism, excretion, and evaporation

occur after approximately 15 to 45 minutes

What are the physiological effects of alcohol?

Neurobiology of Alcohol Dependence: Focus on Motivational Mechanisms, Gilpin NW, Koob GF.

http://pubs.niaaa.nih.gov/publications/arh313/185-195.htm

Fatty Acid Ethyl Esters

Mechanism of action

Exact molecular targets and mechanism of

action uncertain

• A central nervous system depressant

• Direct effects on cardiac muscle, thyroid

tissue and hepatic tissue.

• Metabolic effects - Hypoglycaemia

CNS neurotransmitter systems

Enhanced systems:

• binds directly to the gamma-aminobutyric

acid (GABA) receptor in the CNS and

causes sedative effects

• 5-HT receptor agonism responsible for

– GABAergic

– glycinergic

– cholinergic effects

• Nicotinic acetylcholine receptors

CNS neurotransmitter systems

Inhibited systems:

• NMDA

• Ca2+ channels

• K+ channels

CNS physiological effects of alcohol?

Neurobiology of Alcohol Dependence: Focus on Motivational Mechanisms, Gilpin NW, Koob GF.

http://pubs.niaaa.nih.gov/publications/arh313/185-195.htm

Nucleus accumbens

in basal ganglia

• Pleasure

• Addiction

• etc

Blood alcohol concentrations

effect on CNS

• 20–79 mg/dL – Impaired coordination and euphoria

• 80–199 mg/dL: “Binge drinking” – Ataxia, poor

judgement, labile mood.

• 200–299 mg/dL – Marked ataxia, slurred speech,

poor judgement, labile mood, nausea and vomiting

• 300–399 mg/dL – Stage 1 anaesthesia, memory

lapse, labile mood

• 400+ mg/dL – Respiratory failure, coma

Metabolic effects

• Hypoglycemia occurs secondary to

ethanol's inhibition of gluconeogenesis

– may cause lactic acidosis, ketoacidosis, and

acute renal failure.

• Metabolic acidosis is compounded by

respiratory failure.

• Patients may also present with

hypothermia.

Possible short term consequences of

excess alcohol intake?

Physical consequences

– nausea and vomiting

– impaired judgement and decision making

• slow response time

– memory loss

– blurred vision

– poor muscle co-ordination and reaction

• loss of balance, shakiness

– Inhibition of breathing and gag reflex

– Alcohol poisoning : confusion, drowsiness,

sleep, coma, death

– Hangovers: headache, nausea and vomiting

Social consequences

– Feeling bad about yourself and embarrassed

by your actions

– Losing money that you need for other things

after reckless spending on alcohol

– Having unprotected sex, or unwanted sex.

This might lead to unwanted pregnancy, or

sexually transmitted diseases (STIs)

– Break down of relationships as a result of

your behaviour

– Loss of job

Community consequences

– Increased aggressive behaviour

– Injury to drinker or others

– Drink driving – increased accidents

– Hospital attendance

Possible long term consequences of

excess alcohol intake?

Physical or social and can affect the

surrounding community

• Physical and psychological dependence

(alcoholism)

• Mental health problems - depression and

anxiety

• Problems at school, at work and with

relationships

• Increased risk of sexual problems

(especially male impotency)

• Organ damage

Which organs are damaged by long term

excess alcohol intake?

Organ damage

• CVS: hypertension, myocardial damage

• Liver: fatty liver, inflammation, necrosis,

fibrosis – cirrhosis, liver failure, cancer

• Stomach: inflammation and bleeding

• Pancreas: inflammation ie pancreatitis

• CNS: neuronal damage, dementia,

tremors, stroke

• Endocrine system: problems with blood

sugar control, loss of libido, reduced fertility

Brain

Heart

Liver

Pancreas

Stomach

• http://edupalm.meddent.uwa.edu.au/museu

m/search.php

Do you know any myths or

misconceptions regarding alcohol?

Myths or misconceptions

You can lower your blood alcohol, ie sober up, by:

– vomiting

– breathing fresh air

– exercise

– having a cold shower

– drinking hot coffee

• The only way to sober up is for your body to

metabolize and eliminate the alcohol in your

system. All of these other manoeuvres have

no effect on your blood alcohol.

Myths or misconceptions

Alcohol is legal so why all the fuss

• This ignores the fact that excessive

consumption of alcohol can be harmful to our

short and long term health

If someone is very drunk or passes out then it’s best

to let them sleep it off.

• As alcohol depresses the CNS, people who

pass out may have problems maintaining their

airways should they vomit. These people

should be watched.

Myths or misconceptions

Teenagers can’t become alcoholics because they

have not been drinking for long enough

• Studies have shown that people that start

drinking earlier are more likely to become

alcohol dependent.

Parent: My child is going to drink anyway whether I

like it or not so I might as well buy them alcohol

so I can control how much and what they drink

• There is very little evidence that parents are

supplying their children with alcohol has the

effect of controlling the amount consumed.

Alcohol and Disease

Dr Bastiaan de Boer

School of Pathology and Laboratory Medicine

University of Western Australia

ALCOHOL AND DISEASE