Welcome, caffeine lover!
If you’re reading this, it’s probably because you’ve wondered how your morning espresso could be affecting your quality of sleep. Or maybe you’re concerned about the amount of caffeine in your favorite green tea.
In any case, rest assured, you are in the right place! Grab your bowl of coffee (or not, it all depends on the time!), make yourself comfortable and let's dive together into the exciting world of caffeine.
Where do we find caffeine in our daily lives and in what quantity?
There's coffee in caffeine, and yes, coffee is the preferred source of caffeine for many people. But be aware that it's found in many other everyday foods that we don't necessarily think about.
🍫 Foods containing caffeine
- 🫖 Tea (because yes, theine = caffeine, it’s the same thing)
- 🥤 Coke
- 🍫 Chocolate
- 🍜 Guarana
- 🧉 Yerba mate
- 🍵 Matcha tea
- 🐮 Energy drinks
This means that you ingest caffeine every day, without necessarily realizing it! But don't panic about your sleep, the effects of caffeine are dependent on the quantity contained in the food .
For example, coffee contains the most caffeine, with 135 mg of caffeine in an 8-ounce cup of brewed coffee, or ⅓ of the recommended daily dose. For comparison, there is only 50g of caffeine in an 8-ounce cup of brewed tea.
So, in terms of caffeine quantity, you can drink almost three times more tea than coffee to get the same effects! On the other hand, you will go to the toilet more often 🙄
The Canadian government has summarized the doses of caffeine contained in different foods on this very handy page .
How does caffeine keep you awake 💤?
If many of us jump on caffeine in the morning, it's because it chases sleep away. It helps you wake up and it's still super practical. And to understand why, we'll first have to introduce adenosine.
🧠 The hide and seek between adenosine and caffeine
Adenosine is a molecule which, when you are awake, accumulates in your brain, on specific supports called receptors .
The more adenosine you have attached to the receptors, the more tired you feel . In fact, your brain is like a room full of electrical outlets, where each outlet is an adenosine receptor. When adenosine plugs into those outlets, bam! You feel tired and ready to fall asleep.
But caffeine, as smart as a fox 🦊, is a champion of hide-and-seek. It slips in and occupies these sockets in place of adenosine , without activating the receptors.
Result? The fatigue signal is not triggered, the receptor can no longer be activated by adenosine, because there is already caffeine in its place! The brain is fooled, you feel awake and ready to run a marathon. On the other hand, when it comes to falling asleep, of course, it's more difficult...
Caffeine, Anxiety and Sleep Disorders
The health effects of caffeine are highly debated in the scientific community. The consensus indicates that a daily dose of up to 400 mg (value found on our Canadian link above, or, closer to us, on the EFSA website , the European Food Safety Authority).
But it has a clear effect, sometimes from the first dose, or in case of abuse.
Caffeine can increase your anxiety (link in English), making your sleep more fragile and reducing your deep sleep. You know, that stage of sleep where you dream about flying cats or giant cookies.
Caffeine, by blocking adenosine, prevents you from relaxing, and above all, activates the anxiety machine. The result is an increase in nocturnal ruminations, which has the effect of sabotaging your night and affecting the quality and duration of sleep.
The effects of caffeine: a question of timing 🕦
You know that party guest who doesn't understand the concept of a "nightcap"? Well, it's caffeine! It likes to hang out in your brain.
Its half-life is 5 to 6 hours. This means that after this time, half of the caffeine you consumed is still present in your body. So, if you have a cup of coffee at 6 p.m., you still have caffeine in your body at midnight . And that's not very nice for your night's sleep.
⌚️ So, what time should you consume caffeine?
So, if you want to sleep soundly when you go to bed at midnight, you should consume your last espresso (or can of Red Bull or whatever your favorite ice cream shop is) at noon.
👉 That is 12 hours before going to bed . This way, the caffeine will have been assimilated by your body and adenosine will no longer have any competition for its receptors!
To go further, we have written an article on the right timing for drinking your coffee , so that you are always caffeinated at the right time without risking insomnia.
Take care of your sleep by regulating your caffeine intake
As we have seen, caffeine is there to keep you awake. Logically, it can cause disturbances in your sleep depending on the quantity absorbed and the time of ingestion.
To maintain good quality sleep, we therefore recommend that you pay attention to your caffeine consumption. Whether in the form of coffee, tea or soda, avoid ingesting it before going to sleep!
☕ What is the daily dose of caffeine?
As we said, an adult should not ingest more than 400 mg of caffeine per day to stay healthy. Let's do a little math and see how much of a drink that corresponds to:
- ☕️ ☕️ ☕️ 3 cups of coffee of 237 ml
- 🫖 🫖 🫖 🫖 🫖 🫖 🫖 🫖 8 cups of tea of 237 ml
- 🥤 🥤 🥤 🥤 🥤 🥤 🥤 🥤 8 cans of coke (but don't do this, it's almost three times the recommended daily dose of sugar)
These are the amounts you can eat no later than 6 hours before going to bed or ideally before noon.
But there's more to life than caffeine if you want to take care of your nights. We've also prepared a guide for you to have a deep and restorative sleep and tips for sleeping better for top-level sleep quality.
The final word: caffeine and sleep can go well together 🤝
Now you know how caffeine works, and when and how to consume it to preserve your sleep.
She's great in the morning to beat up Morpheus and help you wake up, and much less great later, when you want to make up with the god of sleep to go to bed.
So remember that timing is everything ! Enjoying caffeine, as long as it's at least 6 hours before you go to sleep, won't harm your beautiful nights. Sweet dreams 😴!