Sleep, caffeine, and alcohol: discussing health choices

B2
90 min
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1

Think about these questions before watching. Share your ideas with a partner.

  1. Describe your typical daily routine when it comes to managing your energy. For example, what do you rely on to wake you up in the morning or to help you relax in the evening?
  2. Beyond just the number of hours, what do you believe are the key ingredients for a truly restful night's sleep? How can you tell the difference between a long sleep and a high-quality sleep?
  3. Many people have strong habits related to food and drink, like a morning coffee or an evening tea. To what extent do you think people are aware of how these habits affect other aspects of their health, such as their sleep quality?
2

Watch the video carefully. Pay attention to the main ideas and key details.

Video script105 segments · click a timestamp to jump

Many of us like to start the day with a cup of coffee

and perhaps end the day with a glass of wine

or some other kind of alcoholic drink.

But it turns out that these two substances,

alcohol and caffeine, can have surprising impacts on our sleep.

[Sleeping with Science]

(Music)

Let's start with caffeine.

Caffeine is in a class of drugs

that we call the psychoactive stimulants.

And everyone knows that caffeine can make them more alert.

It can wake them up.

But there are at least two additional,

hidden features of caffeine

that some people may not be aware of.

The first is the duration of action of caffeine.

Caffeine, for the average adult,

will have what we call a half-life

of about five to six hours.

What that means is that after about five to six hours

50 percent of that caffeine that you had

is still circulating in your system.

What that also means is that caffeine has a quarter-life

of about 10 to 12 hours.

In other words, let's say that you have a cup of coffee

at 2pm in the evening.

It could be that almost a quarter of that caffeine

is still swilling around in your brain at midnight.

And as a result, it can make it harder for an individual

to fall asleep or even stay asleep soundly

throughout the night.

So that's the first feature of caffeine.

The second issue with caffeine

is that it can change the quality of your sleep.

Now some people will tell me

that I'm one of those individuals

who can have an espresso with dinner,

and I fall asleep fine, and I can stay asleep.

But even if that's true, it turns out

that caffeine can actually decrease the amount

of deep, non-rapid eye movement sleep that we have,

stages three and four of non-REM sleep.

That's that sort of restorative deep sleep.

And as a consequence, you can wake up the next morning,

and you don't feel refreshed,

you don't feel restored by your sleep.

But you don't remember waking up,

you don't remember struggling to fall asleep,

so you don't make the connection,

but nevertheless you may then find yourself

reaching for two cups of coffee in the morning to wake up

rather than one.

So that's caffeine, but now let's move on to alcohol,

because alcohol is perhaps one

of the most misunderstood sleep aids out there.

In fact, it's anything but a sleep aid.

And it can be problematic for your sleep

in at least three different ways.

First, alcohol is in a class of drugs

that we call the sedatives.

But sedation is not sleep.

And studies teach us that those two things

are really quite different.

Sedation is a case

where we're simply switching off the firing

of the brain cells, particularly in the cortex.

And that's not natural sleep.

In fact, during deep non-rapid eye movement sleep,

for example, the brain has this remarkable coordination

of hundreds of thousands of cells

that all of a sudden fire together,

and then they all go silent,

and then they all fire together, and then they go silent,

producing these big, powerful brainwaves

of deep non-REM sleep.

And so that's the first way

in which alcohol can be problematic.

We're mistaking sedation for deep sleep.

The second problem with alcohol

is that it can actually fragment your sleep.

Alcohol can actually trigger and activate during sleep

what we call the fight or flight branch

of the nervous system,

which will therefore wake you up more frequently

throughout the night.

And alcohol can even increase the amount

of alerting chemicals that are released by the brain,

once again fragmenting your sleep.

The third and final issue with alcohol and sleep

is that alcohol can actually block

your rapid eye movement sleep, or your dream sleep.

And as we'll learn in subsequent episodes,

REM sleep, or rapid eye movement sleep, dream sleep,

provides a collection of benefits,

things such as your emotional

and mental health, even creativity.

Now I'm not here to tell anyone how to live.

I don't want to be puritanical.

I'm just a scientist.

What I want to try and do is provide you

with the information about the relationship

between caffeine and alcohol on your sleep

so then you can make an informed choice

as to how best you want to live your life

when you're trying to prioritize your sleep health.

3

Answer these questions in your own words. Support your answers with evidence from the video.

01According to the video, what does the concept of 'half-life' reveal about caffeine's long-lasting effects on the body?
Sample answerIt shows that caffeine stays in your system for a long time. The speaker says its half-life is about five to six hours, which means half of it is still there after that time. So, a coffee at 2 p.m. can still be affecting you at midnight.
02In what way can caffeine negatively affect your sleep even if you don't have trouble falling asleep?
Sample answerEven if you fall asleep fine, caffeine can reduce the amount of deep, restorative sleep you get. This means you can wake up feeling tired and not refreshed, but you might not connect it to the coffee you had.
03How does the video distinguish between the sedation caused by alcohol and the process of natural deep sleep?
Sample answerThe speaker explains that sedation just 'switches off' brain cells, while natural deep sleep is a very active process. During deep sleep, hundreds of thousands of brain cells fire together and then go silent, creating powerful brainwaves.
04Why does the speaker argue that alcohol is one of the most misunderstood sleep aids?
Sample answerBecause while people think it helps them sleep, it actually harms sleep in several ways. It's just sedation, not real sleep, it fragments your sleep during the night, and it also blocks your dream sleep, which is important for mental health.
4

Key vocabulary for discussing habits and health

Vocabulary
These expressions will help you communicate more naturally about the effects of lifestyle choices on your well-being.
Examples
To be a light sleeper — to be someone who is easily woken up by noise or other disturbances.
This is a common, informal way to describe your natural sleep tendency. The opposite is 'a heavy sleeper'. For example: 'I'm a very light sleeper, so any caffeine after lunch is a bad idea for me.'
To toss and turn — to move around restlessly in bed because you are unable to sleep comfortably.
This is a common idiom to describe a bad night's sleep. For example: 'I was tossing and turning all night worrying about my exam.'
To feel groggy — to feel dazed, weak, and not fully awake, especially after sleeping.
This is a great adjective to use when you wake up and don't feel refreshed, as mentioned in the video. For example: 'Even after eight hours, the poor quality of sleep made me feel groggy all morning.'
To cut down on (something) — to reduce the amount or quantity of something you consume or do.
This is a very common phrasal verb for talking about changing habits. For example: 'My doctor advised me to cut down on caffeine to improve my sleep quality.'
In the long run — over a long period of time; eventually.
Use this phrase to discuss the future effects of a current action. For example: 'Relying on alcohol to sleep might seem to work now, but it's harmful in the long run.'
5

Decide if each statement is true or false. Correct the false ones.

01According to the video, caffeine has a half-life of about 10 to 12 hours.
02The speaker's main goal is to provide scientific information so that viewers can make their own informed decisions about their habits.
03The video explains that consuming alcohol can prevent you from getting enough REM sleep, which is important for creativity.
04Alcohol helps you sleep more soundly by calming the 'fight or flight' branch of your nervous system.
05Even if a person can fall asleep easily after drinking coffee, the caffeine can reduce the amount of deep, restorative sleep they get.
6

Complete the sentences with words from the box. One word is extra.

Word bank
01My doctor advised me to caffeine if I want to improve my sleep quality.
02Even after eight hours of sleep, I still felt and couldn't concentrate on my work.
03My husband is such a that even the slightest noise from the street wakes him up.
04Giving up late-night coffee might be difficult at first, but it will be much better for your health.
05I was so worried about the exam that I all night and barely slept a wink.
7

Choose the best answer based on what you heard in the video.

01What is the speaker's primary purpose in the video?
02According to the video, what is a potential consequence of drinking a cup of coffee at 2 PM?
03How does alcohol disrupt the sleep cycle, according to the video?
04Which of the following recommendations for improving sleep is NOT made in the video?
8

Habits and consequences

Complete the sentences by matching the two halves. Think about cause and effect related to sleep and lifestyle choices.

Match each item on the left with the correct item on the right.

Drag or click to match
Definitions
9

Discuss these questions with a partner. Try to use vocabulary from the lesson.

  1. The video explains that caffeine can reduce deep sleep, making you feel unrestored. Think about the culture around work and productivity in your country. To what extent do people rely on stimulants like coffee to perform, and what might be the consequences of this `in the long run`?
  2. Imagine a friend who is a `light sleeper` and often complains about `tossing and turning`. They drink several cups of coffee a day but don't see the connection. How would you persuade them to try `cutting down on` caffeine, and what advice would you give to help them manage feeling `groggy` in the beginning?
  3. Some people believe personal health is a private matter, while others think governments and companies should actively promote healthier habits. Considering caffeine's impact on sleep quality, should there be public health campaigns or warnings similar to those for alcohol or tobacco? Debate the pros and cons of such an approach.