D. Healthy Living · Healthy Living

Alcohol: What It Does to the Body and Brain

D1.2 A1.6About 45 minutes

Learning goals

I can explain that alcohol is a drug that slows down the brain and body.
I can describe short-term and long-term effects of alcohol use.
I can name factors that change how strongly alcohol affects a person.

Words to know

alcohol
A drug found in drinks like beer, wine, coolers and liquor. It slows down the brain and body.

depressant
A type of drug that slows down messages between the brain and the body.

intoxicated
Being affected by alcohol or another drug, so the body and brain don't work as they normally do. Also called being drunk or impaired.

short-term effect
An effect that happens soon after using a substance and lasts hours or a day.

long-term effect
An effect that builds up over months or years of use.

alcohol poisoning
A dangerous emergency that can happen when someone drinks too much alcohol too quickly. Call 911.

A drink that's also a drug

You've probably seen alcohol at restaurants, on TV, or at family celebrations. Many adults drink it. But did you know alcohol is a drug? Today you'll learn what alcohol does inside the body, why the law says it's for adults only, and what makes its effects stronger or weaker.

Remember from Grade 4

You learned that nicotine in cigarettes and vapes is addictive and that smoke harms the lungs and heart. Like nicotine, alcohol is a substance that changes how the body works, and that can lead to addiction.

What alcohol does

Alcohol is a depressant. That doesn't mean it makes you sad. It means it slows down the messages travelling between the brain and the body.

When someone drinks, alcohol goes from the stomach and intestines into the blood. The blood carries it all around the body, including to the brain. The liver works to break alcohol down, but it can only do this slowly. Only time sobers a person up. Coffee, cold showers or exercise do not.

In Ontario, it is against the law to sell alcohol to anyone under 19, and people under 19 can't buy it. Young people's brains are still developing, so alcohol can harm them more.

Alcohol travels from the stomach and intestines into the blood, which carries it to the brain. The liver breaks it down slowly; only time helps.

Short-term effects (hours to a day)	Long-term effects (months to years of heavy use)
Dizziness, trouble with balance and walking	Liver damage
Slurred (unclear) speech and blurry vision	Heart problems and high blood pressure
Slower reaction time, so injuries and crashes are more likely	A higher risk of some cancers
Poor judgement: making risky choices	Harm to the brain, especially a young, developing brain
Strong emotions, like getting angry or sad	Addiction: feeling you need alcohol and finding it very hard to stop
Nausea and vomiting; headache and tiredness the next day (a hangover)	Problems with relationships, school, work and money
Alcohol poisoning: an emergency	Mental health problems, such as feeling depressed or anxious

Effects of alcohol use. Many adults choose to drink small amounts or not at all; the risks grow the more someone drinks.

Alcohol poisoning is an emergency

Signs include: can't wake up, very slow or uneven breathing, vomiting while passed out, confusion, cold or pale or bluish skin. Call 911. Never leave the person alone, and don't let them "sleep it off". Turn them on their side so they don't choke.

Why doesn't alcohol affect everyone the same way?

The same drink can affect two people very differently. Things that change how intoxicated someone becomes include:

Amount: more alcohol means stronger effects.
Speed: drinking quickly gives the liver no time to keep up.
Body size: a smaller body has less blood and water, so the alcohol is more concentrated. Kids' bodies are small, so even a little alcohol can be dangerous.
Sex: on average, the same amount of alcohol affects females more strongly than males.
Food: drinking on an empty stomach makes alcohol reach the blood faster.
Emotional state: feeling upset, stressed or tired can change how alcohol affects someone.
Mixing: combining alcohol with cannabis, medicines, other drugs or energy drinks is risky. Energy drinks can hide how drunk a person really is.

Worked example

Let's figure out who is more affected

Two adults each drink the same amount of alcohol. Person A is tall, drank slowly over 3 hours and ate a full meal. Person B is small, drank quickly in 30 minutes and hadn't eaten all day.

Amount: the same for both.
Speed: B drank much faster, so the liver couldn't keep up.
Body size: B is smaller, so the alcohol is more concentrated in their body.
Food: B had an empty stomach, so the alcohol reached B's blood faster.

Person B will be much more intoxicated, even though both drank the same amount. Three factors all point to B.

Same amount, different effect: speed, body size and food all point to Person B being much more intoxicated.

Worked example

Let's connect an effect to a danger

Why is it dangerous for someone who has been drinking to ride a bike, swim or drive?

Alcohol slows reaction time: they can't brake or move away fast enough.
Alcohol harms balance and coordination: falls and crashes are more likely.
Alcohol harms judgement: they might think they're fine when they're not.
In Canada, driving while impaired by alcohol or drugs is a crime.

Alcohol makes injuries much more likely because it slows the brain and affects judgement. People who have been drinking should never drive.

Just for fun

Your ruler test is secretly a stopwatch! A dropped ruler falls about 5 cm in the first tenth of a second and about 20 cm in two tenths of a second. So if you catch it at the 20 cm mark, your reaction took about 0.2 seconds.

Hands-on activity

Reaction-time ruler test

You need: a 30 cm ruler and a grown-up.

Your grown-up holds the ruler at the 30 cm end so it hangs down. Put your thumb and finger open at the 0 mark (not touching).
Without warning, your grown-up drops it. Catch it as fast as you can. Read the number where you caught it. A smaller number means a faster reaction.
Do it 3 times and record your results.
Now try while counting backwards by 7s from 100 out loud. Is your catch slower?
Talk about it: a distraction made your reaction slower. Alcohol slows reactions even more and also affects judgement. Imagine what that means for driving or swimming.

This activity is safe; it uses only a ruler. It does not show what being drunk is like; it shows why reaction time matters.

Your turn

What kind of drug is alcohol, and what does that mean?

Which organ breaks down alcohol?

Name three short-term effects of alcohol.

Name two long-term effects of heavy drinking.

What is the legal age to buy alcohol in Ontario?

Name three factors that affect how intoxicated a person becomes.

What should you do if someone can't wake up after drinking?

More practice: warm-up

True or false: coffee sobers a person up.

Is alcohol a drug?

Does drinking quickly make the effects stronger or weaker?

Does food in the stomach make alcohol reach the blood faster or slower?

Which body part does alcohol travel to that affects thinking?

More practice: on your own

Why can even a small amount of alcohol be dangerous for a child?

Why are energy drinks and alcohol a risky mix?

Explain why alcohol and swimming don't mix.

A movie shows people drinking and having fun with no problems. What's missing from the story?

What is the difference between a short-term and a long-term effect?

Challenge

Two people drink the same amount at the same speed. One is upset and hasn't eaten; the other is calm and just had dinner. Who is likely more affected, and why?

Why do you think Ontario's law sets an age limit for alcohol?

Create a short public service message for kids about alcohol, using two facts from this lesson.

Check your understanding

Quiz

Alcohol is a depressant, which means it...

Which organ breaks down alcohol?

Which is a long-term effect of heavy drinking?

What sobers a person up?

Which person would likely be most affected by the same drink?

Someone who drank a lot won't wake up. You should...

For parents and teachers

Big idea: This lesson covers the Grade 5 expectation to describe the short- and long-term effects of alcohol use, and identify factors that can affect intoxication (D1.2). The curriculum's factors (amount consumed, speed, sex, body size, emotional state, and combinations with other drugs such as cannabis, food, or substances such as energy drinks) are all included.

How to help at home:

Share your family's values about alcohol in a calm, honest way. Children this age listen closely to their parents on this topic.
If alcohol is in your home, store it out of reach and talk about why.
Point out alcohol ads and how they show only the fun side.

Common difficulties: thinking alcohol isn't a "real" drug because it's legal for adults; believing myths (coffee or cold showers sober you up). If your child asks about a family member's drinking, answer honestly and simply, and reassure them that an adult's drinking is never their fault or responsibility to fix.

This lesson builds critical thinking (A1.6) as your child connects effects to real-life risks.