Hey there, welcome back to the channel. We all know that caffeine can affect our sleep
and can keep us up at night, and I'm a little surprised at myself that we haven't discussed
caffeine yet on this channel. So today we are going to fix that by giving
a brief overview of how caffeine affects our sleep, and also how late we can have caffeine
before bed. Hey everyone, my name is Matthew, and welcome
to Calm Insomniac where we're a community of people trying to get a better night's sleep. If you enjoy learning about sleep health,
sleep tips, and relaxing classical music, then please like, subscribe, and hit the bell
icon for notifications.
Let's start with the basics by asking a very
simple question: what is caffeine? Caffeine is a naturally occurring substance. It has a bitter taste, and is commonly found
in plants, such as coffee beans, tea leaves, cacao, and Kola nuts (which are used to flavor
a lot of sodas). Caffeine can also be synthetic, or man-made. Synthetic caffeine is often found in over-the-counter
medicines, such as cold remedies and pain relievers. Synthetic caffeine can also be found in products
such as energy drinks or caffeine chewing gums. According to one study, 90% of Americans consume
caffeine-infused beverages daily. Additionally, another study found that most
people under-report their daily intake of caffeine. Now, this under-reporting is done unintentionally
because most people don't realize, or forget, just how many products contain caffeine. Most people associate caffeine with coffee,
but caffeine is found in all kinds of products. Tea, iced tea, chocolate, hot chocolate, candy
bars, soda, those all contain caffeine. One cup of coffee which is 125 ml contains,
at most, 100 mg of caffeine. And most people self-report that they consume
100-500 mg of caffeine a day, so about 1-5 cups of coffee.
But, like I said, most people forget or don't
realize just how much caffeine they're actually consuming. So researchers have found that these self-reporters
are actually consuming anywhere between 154-1,285 mg of caffeine a day. So this can be problematic because people
don't realize just how much caffeine they're consuming every day. And, furthermore, most people's tolerance
for caffeine is much higher than they realize. Now that we know what caffeine is, the next
logical question is: how does caffeine affect our body? Caffeine is a stimulant. A stimulant is a substance which raises levels
of physiological or nervous activity in the body. In this case, we're mostly talking about our
central nervous system.
Specifically, caffeine achieves this by the
way it reacts with our adenosine receptors. So, let's go ahead and break this down. Adenosine is an organic compound found in
our cells and central nervous system which help transfer energy. And receptors are structures made of protein
that bind with special molecules. So when adenosine binds with a receptor, we
begin to feel sleepy because this causes our neural activity to slow down. One of the reasons this happens is because
adenosine is a vasodilator, meaning it dilates (or opens) our blood vessels which allows
for proper oxygenation during sleep. But when we consume caffeine this process
is interrupted. Instead, caffeine binds to adenosine's receptors
and this doesn't cause our neural activity to slow down.
This means that adenosine has far fewer receptors
available to bind to, so instead our neural activity begins to speed up. So, think of adenosine as the brakes, and
caffeine as the accelerator. And when our neural activity increases, this
causes our pituitary gland to activate. The pituitary gland releases hormones which
signal the adrenal glands to release adrenaline, which is responsible for our "fight or flight"
response. So all these processes keep us in an alert
state, increase our awareness, and provides extra energy to our entire system. So now that we know what caffeine is and how
it affects us, let's specifically address how caffeine affects our sleep. I know we're all very aware that caffeine
keeps us up at night and prevents us from getting a good night's sleep, but let's dive
into this a little bit more specifically.
Studies have shown that consuming caffeine
in close proximity to bedtime increases sleep latency and decreases total sleep time. So this just means it takes us longer to fall
asleep, and the total amount of time we're asleep is lessened. Additionally, studies have shown that when
we consume caffeine close to bedtime, the amount of time we spend in deep sleep is decreased. But here's one of the biggest problems with
consuming caffeine in close proximity to bedtime. When consumed as a beverage, caffeine is absorbed
into our body through our gastrointestinal tract and quickly reaches peak effectiveness
within 30-75 minutes. However, it takes 3-7 hours (or sometimes
longer) for our body to completely eliminate the caffeine from our system. And since we often don't realize just how
much caffeine we're consuming throughout the day, this problem compounds. So let's say for example that you drink three
cups of coffee a day, with your first one at 9 a.m., the second one at noon, and your
final cup at 2 p.m. With each new cup of coffee, there's a good
chance that the previous cup's caffeine is still in your system and has not been completely
eliminated.
Now let's say that when you get home for dinner
you like to eat a chocolate bar as your dessert. And then when you're relaxing before bed you
like to drink a cup of tea. By the time you've gone to bed there is still
quite a bit of caffeine still in your system that hasn't been eliminated yet. One final problem with consuming caffeine
too close to bedtime is that caffeine is a diuretic, and a diuretic helps release excess
salt and water from our body through urination.
So if you drink too much caffeine before bed,
there's a good chance you'll be up all night because you constantly need to use the bathroom. So with all that in consideration, how late
in the day can we have caffeine before bed? There's a general consensus that caffeine
shouldn't be consumed too late in the day, and this is especially true for caffeine-infused
beverages. But specific recommendations vary among research
studies. Some research studies suggest having caffeine
no later than 6 hours prior to bed. Other studies suggest having caffeine no later
than 10 hours before bed. And even other studies suggest specific times
of day, such as no later than noon, or no later than 2 p.m. What's clear is that caffeine, ideally, shouldn't
be consumed later than the early afternoon. So this is unfortunate for anyone who enjoys
drinking a cup of tea before bed, or who likes having a cup of coffee with dessert. Regardless, you have to make a personal choice. Consider your own tolerance for caffeine,
and consider how caffeine affects your body, and how it potentially affects your sleep.
And if it does interfere with your sleep then
you should be willing to make an adjustment. There we go, that is an overview for how caffeine
affects our sleep and how late we can have caffeine before bed. This is a topic I'm going to continue to discuss. And, in fact, in one of my next videos I'm
going to discuss further how caffeine affects our sleep, as well as how caffeine affects
our daytime functioning, and the coffee cycle. So if you aren't subscribed already, be sure
to subscribe so you get notified about that immediately. Let me know in the comments down below: how
much caffeine do you think you consume in the day, and how late in the day is your last
cup of coffee? Thank you so much for watching, I hope you
enjoyed this, I hope you learned something. Don't forget to like, subscribe, follow me
on Facebook and Pinterest, check out my website, and join my email list. All of those links are down below. If you enjoyed this video and want to learn
more about sleep health, then I suggest you check out this playlist right over here.
And if you missed my recent video where I
discuss how to fall back asleep when you wake up in the middle of the night, then check
out this video right over here. Thanks for watching, I'll see you next time..
