[thedoc (OP)]

Why is it that when I drink coffee it can make me more sleepy? Other people seem to drink coffee and wake up!
Asked by Matt Burnett


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[chapter podcast=1000538 track=13.10.20/Naked_Neuroscience_2013.10.20_1001505.mp3]  ...or Listen to the Answer[/chapter] or [download as MP3]

[thedoc (OP)]

We answered this question on the show...

We posed this question to the brain panel.
Mike -   It depends on the time course.  I’d be surprised if somebody would [img float=right]/forum/copies/RTEmagicC_sleeping_student_02.jpg.jpg[/img]drink a cup of coffee then immediately feels sleepy.  But I think it’s perfectly reasonable to feel sleepy a little bit later on because what's happening when you drink the coffee is that caffeine is complicated but its main effect is to block the action of a transmitter called adenosine which is a sort of dampening down a transmitter if you like in the brain.  So, when you block the effect then you feel more awake.  Later on, when the coffee effect wears off after it gets eliminated in every 4 hours or so, so when that's gone, the adenosine is still chugging along there and then that may then switch the other way so you feel more sleepy.  So, I don’t know of a circumstances where you would drink coffee and then suddenly feel sleepy.
Bill-   Except perhaps if you had a strong association with coffee as a thing that you took next to going to sleep.  Like children here, nursery melodies and they're put to sleep by it.  If you had a routine in which you drank coffee and then went to sleep, it may be a signal to sleep and would help you get to sleep.  Is that possible?
Hannah -   Or maybe he associates coffee with incredibly boring activities like being in the office.
Katie -   Feeling really tired?
Hannah -   Maybe there's other listeners out there who experiences also.  If so, we’d like to hear from you. 

[CliffordK]

I've always thought that coffee can cause a spike in alertness, followed quite soon afterwards by a crash. 

Perhaps heavy coffee drinkers are also often sleep deprived, or perhaps don't get "good sleep", causing additional rebound drowsiness. 

[Super Hans]

My guess is that this person is just one of those people who don't seem to be affected by caffeine, or need very large doses for it to take effect.

Then the sleepy effect would be caused by simply just having a warm drink, which often makes people tired. But would work just well with any hot drink like tea or hot chocolate.

If it turned out not to work with other hot drinks, obviously this theory wouldn't work,

[bizerl]

I'm sure I heard Chris (or maybe it was Dr Karl) say once that in some people, coffee can stimulate the part of them that wants to sleep, thus making them sleepier. I'm sure when the doctor described it it was much more scientific and lucid than that, but that's the message I took from it.

I sometimes wonder whether one can develop a dependence on caffeine which means they are intrinsically more tired all the time, and drinking coffee just brings them back to a "normal" level of background tiredness.

Also, if I drink coffee at night, I get tired because it's night and I want to go to bed. I don't think the coffee has a major effect on this (not as much as my kids anyway  [])

[CliffordK]

I sometimes wonder whether one can develop a dependence on caffeine which means they are intrinsically more tired all the time, and drinking coffee just brings them back to a "normal" level of background tiredness.

Yes, I think that is a major component of caffeine addiction.  That once addicted, one is no more alert than if a person wasn't addicted.  Just one has to have the coffee boost to get back to normal.

Add a little sleep deprivation, and the coffee may be counterproductive.

I have been mostly off of coffee & caffeine for quite some time.  But, there seems to remain a little bit of "brain fuzz" that I don't think was there before I first got addicted to coffee.

[luckoo]

I can't drink coffee. If i do drink, i need only one cup and my body crashes. First of all, it causes emptying my bowel, and secondly, i want to sleep. I remember i have had days in my past that coffee have made me more alert but thats years ago. I actually stopped to drink coffee for years and now tried to start it again - i couldn't - i can't see any positive effect in it. I could drink cup of coffee in the evening and go to sleep. Perhaps it is adrenal system and cortisol which are going over.

[Angie]

I have this problem sometimes, not all the time. I drink about 2 cups of coffee a day, generally in the morning, but some mornings almost as soon as I have drunk my cup of coffee (ie within half and hour and often before I have finished the cup) I feel an overwhelming tiredness - my eyes get really droopy feeling, my body feels really heavy and I feel like I can barely function...
Its strange because its not everytime, I have also had the experience where after a strong cup of coffee I am bouncing off the walls... so its NOT because I'm a person whom caffeine doesn't affect at all.
I'm still trying to find out why!

[Jamie]

Nice to see this topic being discussed.

I too find coffee makes me sleepy. I've never had any sort of 'high' or increased alertness from it.

It's not that I'm addicted - I often rarely drink it. But when I do, I get sleepy.

This was most noticeable when I tried caffeine tablets one day, to keep myself awake in work. On taking them, they had no effect, but a few hours later, I was more tired than ever, and could hardly seem to keep awake, so the 'warm drink' affect doesn't seem to be applicable either.

I've heard it suggested that I may be slightly allergic to caffeine, and that the response is therefore a typical response when the body is trying to deal with toxins.

Any thoughts on this?

Cheers,
 Jamie

[Camren]

Yes I too get tired when I drink coffee. Almost instantly, I am new to coffee so it bring a habit before bed can be ruled out.

[alilfroggy]

Theobromine may be the culprit as a vasodilator. Caffeine is broken down and metabolised by the liver  into theobromine, paraxanthene and theophylline. This may ultimately have to do with how well caffeine is metabolised by the body.

[Chrissy]

I drink coffee from the time I wake up untill I fall asleep at night. It makes me so sleepy I start yawning while I'm drinking it and I get my normal 7 hours or more of sleep. I just assumed it had the opposite effect on me because of how much I drink it. (7-10 cups normally per day )

[Anthony]

For me when I drink coffee. It also makes me sleepy. I don't get boost what so ever. I mean after drinking it the next 20 to 30 mins i am struggling to stay awake. I am a medical student so I assumed that maybe it was just me being too sleep deprived and the dosage wasn't strong enough.

So after exam period when I got some rest my friends and I decided to try it out. So i took some when I wasn't sleepy and it wasn't even near the time I usually go bed. It was approx. 6:30 pm and i usually go bed after 2 or so in the morning. Taking it at 6:30, i fell asleep near 7:00 pm

I don't know why it is having this affect on me, but this wasn't always the case. In the past like earlier last year it did its job and perk me up.

Maybe my body has developed some tolerance to it, receptors to caffeine might have become less sensitive. If that is the case though, i would expect that coffee would just then dont have any effect on me. Surprisingly it flipped the scale and went from perking me up to the opposite, making me sleepy.

[Miller]

Interesting discussion. I occasionally have a cup of coffee, mostly just because I like the taste, and often feel myself sleepier than before I had had it. And I'm talking one cup. In the morning. Not sure if it's some kind of placebo effect or if other factors around me are actually what's causing me to become tired. The only thing coffee does seem to do for me is make me pee a lot. Then again, several things that affect most people don't affect me... Vitamin B12? Nah. I suppose I'm just not sensitive like that.

[Tim]

If I am drinking instant coffee I seem to perk up, but for example if I drink instant when I am sleep deprived I'll perk up, but then a few hours later I'll feel more tired than I think I would have otherwise. However - if I make Stove-top Italian 'espresso' coffee that can perk me up like almost instantly for about an hour - quiet extremely so, I get touch hyper and giggly and in a general good mood, then after the hour is up I'll feel sleepy, but the good mood seem to retain. Which is nice. I think this especially true at night, however I try to avoid drinking coffee 3 hours before bed. Doesn't Coffee give you a seratonin boost?  I am really no expert in these matters, but doesn't your brain convert Seratonin into melatonin when the body clock tells it too? If you have extra serotonin, I imagine that melatonin is more readily available? So you feel sleepier? Just a guess.

[Ange]

I too get tired and sleepy after minutes of drinking coffee. I don't drink coffee often, only when I feel the need to like when I need to study for an exam or when I wasn't able to sleep. I find that within 2 hours or possibly less than an hour, my eyes would feel really heavy and instead of feeling pumped to do some tasks, I would be nodding my head off while studying, for example. Even if I drink 2 glasses with good amount of coffee (I try to put a tbsp or a bit more to perhaps counteract the sleepiness & lots of sugar for added energy ), it still makes me sleepy. There was one or two times though, that I would feel really sleepy first ( or take a nap less than half an hour) then after that, I'm gonna be awake and focused on studying. Otherwise, I would call it a night and forget studies!

And, this only happens when I drink coffee. I don't feel sleepy when I drink other hot substances such as hot choco or tea. Also, when it's not summer break I usually get less than 7 or 6 hours of sleep. Sleep deprived ?

[Nicole]

Ive always felt extremely sleepy within 30 mins after drinking a cup of coffee.  I started drinking it in university when I wanted to stay up late, but it only put me out.  I feel like my vrain just shuts down and my body is heavy with sleep.  I'm only 26 and I love to drink coffee, but it still puts me out quick!

[Social_butterfly15]

Hi.. I have the same issue about coffee.. But in my case I feel so tired and sleepy right after a few sip.. i can't even finish a cup. I would start to yawn and my eyes would be watery from feeling so sleepy.  The weird part is I tried drinking instant coffee and I don't feel sleepy. Tried drinking starbucks frap or any brewed coffee and I'd instantly feel like crap.

[Aliyya]

I too feel sleepy after drinking coffee
i only drink it when i cannot fall asleep

[amberrrr]

Happens to me too. I drink coffee to wake up with my two and a half yr old. at first I'm awake buthcrash because im awake and playing with my daugter doing chores running errans.