Q: Does ME/CFS change rate of caffeine metabolism?

Sisyphus

Senior Member (Voting Rights)
I'm not sure where to put this one.
Just wondering if any of the more biologically literate here know if our condition decreases the rate one metabolizes caffeine. The rule of thumb is 50% is metabolized every 5 hours, so by 10 hours it should be gone for practical purposes unless one was drinking Robusta. I suspect the 5hr 1/2 life is a tad simplified.

Since pretty much everything metabolic is broken to some degree I'm wondering if our caffeine metabolism is also slower. It's a different pathway than ATP and ketones, so maybe it's not actually affected.

I use it as a way to be somewhat function for part of the day but don't want to make my sleep worse than it already is. Bad sleep ---> Bad Things Happen. Also, being a zombie all day and not, say, finding an affordable place to live ---> Really bad Things Happen. So I have no easy quick fix.
 
Not a scientific answer.
I gave up all caffeine for a few years as recommended by P D White. All caffiene, so no chocolate, cola, the lot. I didn’t notice any positive difference (and I was miserable) so I took it up again.
I find it hard to get going in the morning, I take 100mg caffeine with two cups of tea which aren’t strong brewed. That makes a brilliant difference to me.
 
I certainly have problems with it disrupting sleep and I never did before ME/CFS. I don't know if it's just my sleep is disrupted anyway but I need to get any intake of caffeine done 12 hours before I would want to sleep which largely makes it something I do on waking. I have had periods where my body felt worse on caffeine but not now so something has changed over the years too.

I haven't seen any investigation into it from research, seems fairly low down on the priorities list but I also can't help think it's another clue to what is going wrong.
 
I'm the opposite. I used to be someone that drank caffeine regularly. When I fell ill I had some caffeine and just like that if made me feel nauseous and gave me a terrible crash (which I had never ever had from caffeine before). I gave it up completely after trying it once more.
 
I have never regularly drank tea or coffee (never acquired a taste for either), but did drink cola. I largely stopped drinking it after my ME/CFS onset except as a stimulant to get through situations that required more physical activity, usually such would be followed by PEM and migraine type headaches, though it is not clear if the caffeinated drinks played a role in this or not.

Some years into my condition (some 10+ years) a clear pattern of a migraine type headache predictably developing some six hours after consuming cola emerged. This does not happen with other sweetened carbonated drinks, suggesting caffeine is the trigger. The six hours has always intrigued me given my adverse reaction (including migraine type headaches) to gluten nearly always starts twenty four (±1hr) hours after consumption.
 
I think it can also vary over time according to disease stage or cycle.

My tolerance was always on the sensitive side but evolved over time.
When mild I always needed a coffee to get me going with a max of three by early afternoon.
When I first became moderate to severe I struggled to tolerate coffee at all, even had a some time off tea altogether. Then had a spell of strictly two teas a day. Now I seem to be able to drink as much tea as I want and an occasional small milky coffee. But still couldn't manage the 2-3 coffees I originally had.
 
I have no idea if this is right, but caffein metabolism is very individual and I think it can change over time.

For ME/CFS there is the added issue of sleep irregularities, and it’s not uncommon to experience sleep issues after doing too much. Because caffein is a stimulant, I suspect it might make it more likely that you push past your limits, either with one big activity or just the total activity over a few days.

In my personal experience, excessive daytime sleepiness and fatigue is often correlated with having done too much lately.

So if you can, you might want to experiment with cutting back on both caffein and activity for a week or two to see if your pattern of symptoms changes.
 
That makes me think more about my response. I also have adhd and caffeine used to make me feel energetic and calmer at the same time. I remember in high school biology class we did a caffeine experiment and my teacher was gobsmacked that my heart rate went significantly down while everyone else's went up.

So, maybe that has an impact on why caffeine started making me ill when I became ill with cfs.
 
I have no idea if this is right, but caffein metabolism is very individual and I think it can change over time.

For ME/CFS there is the added issue of sleep irregularities, and it’s not uncommon to experience sleep issues after doing too much. Because caffein is a stimulant, I suspect it might make it more likely that you push past your limits, either with one big activity or just the total activity over a few days.

In my personal experience, excessive daytime sleepiness and fatigue is often correlated with having done too much lately.

So if you can, you might want to experiment with cutting back on both caffein and activity for a week or two to see if your pattern of symptoms changes.
Agree with this post and @BrightCandle saying it might be cart before horse on sleep and overdoing

I’ve always had sleep issues affected by PEM and over threshold.

I had enough days over enough years however where I eg drank lots of caffeine just to get awake and to working then had to drink tea all day (with colleagues joking caffeine in drip type thing - but it wasn’t espresso just tea with the odd cola at lunch etc) then home to bed and struggled to take clothes off before getting in and falling asleep. even if I had a cup of tea on getting into the house. Rinse and repeat. Sometimes with almost no waking in weekends except for the odd needing the loo.

so unless it was like when I was trying to complete a uni essay for a deadline in a overnighter (and even then you’ve the activity affecting the sleep and only being Able to do that because of the caffeine) and I had goodness knows how many colas just trying to get my brain to work then I think it was the cognitive and physical battering that was causing the sleep differences via overtired and PEM rather than the caffeine.

I think it wears off fast and strangely even though most days I drink a solid amount over the years on days where I haven’t drunk it I got none of the ‘withdrawal’ not ill people would chunter about (like headaches or shakes) although they often were just PEM days or exhausted days where I was too tired to get a tea and didn’t need to nor would it be sensible to push my brain awake - it was just a relief when I had a day I didn’t have to.

I assume from that it probably means it metabolizes fast. Just often isn’t quite enough. Then I have to keep topping it up once it’s there.

When I was really ill and when I was going through a very stressful situation on top then I paused drinking any cola (not tea) as I found it quickly acting on my heart rate and made me nauseous and not anxious but something like it for a while. I now just tend to use cola when eg I need to get home from an appointment where I’ve overdone it or an emergency situation where I need to push myself temporarily more mentally awake. But tea on the other hand is for everything, just a slightly gentler ‘administration’ of required caffeine to function.

I got persuaded into eating a big red velvet cup cake at home time at work one day (I never really ante sweet stuff ant work and this must have been made with a lot of sugar vs even the seeet treats I might normally have) and spent the night literally wide awake on the other hand.
 
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I've had issues with caffeine before ME. Caffeine didn't have a negative effect during the earlier years of ME, I slept fine, but as the years go on I find it does have a negative effect on my energy levels later in the day, it drains me so much that I don't plan outing or walks on days I drink coffee. I limit it to 2 cups a week now. If there's no chocolate or dessert around then I don't think of it as much.

There's a study on a group of Jordanians that shows broccoli helps your body metabolize caffeine faster, allowing it to work its way through your system before bedtime- broccoli induces cytochrome P450 enzymes in the liver, which help in the metabolizing of caffeine molecules. I've tried it but can't say it made a difference.
 
Caffeine didn't have an effect on my ME in the first maybe 15 years, but then it started giving me worse ME symptoms (lethargy, brainfog). Then I had to give up chocolate too. Even decaf and white chocolate contain enough of the xanthines to affect me. So sad.
 
I think it can also vary over time according to disease stage or cycle.

My tolerance was always on the sensitive side but evolved over time.
When mild I always needed a coffee to get me going with a max of three by early afternoon.
When I first became moderate to severe I struggled to tolerate coffee at all, even had a some time off tea altogether. Then had a spell of strictly two teas a day. Now I seem to be able to drink as much tea as I want and an occasional small milky coffee. But still couldn't manage the 2-3 coffees I originally had.

Interesting that tea and coffee work out differently for you. Their composition is different, so it makes sense.
 
If you're interested in caffeine's effects, I came across this today: https://www.sciencedaily.com/releases/2025/05/250529124625.htm It's about caffeine's effects on brain activity during sleep.
Yeah I read that, the abstract at least. I couldn't find the exact amount of time the study placed between caffeine in and subject sleep. It was quoted as 3-5 hours in a report on the study, I couldn't find any specific figure skimming through the paper itself. Didn't read it all, just skimmed. Net: I found nothing to change my 10 hr rule of thumb, or my 8 hour "that could work, maybe" dodge. It does seem to indicate there's no obviously great way for me to deal with this. I tried no coffee for a week, result was net worse not better.
 
I've almost always drank huge amounts of coffee. Something like 5-10 large cups a day. I don't remember if it ever had stimulating effect, I drink it because it relaxes me. Sometimes when I wake up from sleep and can't continue fast, I'll drink a cup of coffee and I'll be back sleeping within hour! (can't tell doctors this though). Don't know about metabolizing times, other than if I sleep more than 12 hours I often have a headache.
 
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