I give numerous talks about sleep and fatigue. What happens when you talk about sleep and fatigue? Very predictably, people become sleepy, especially during my afternoon talks. Right when audiences‘ circadian rhythms are forcing a body temperature plunge, the heads always start to nod off. At least I hope it’s the biology and not my presentation.
I like to try and get a few laughs going to wake people up at these times and one of the stories I use goes something like this…
Almost 20 years ago when I was still a student and very excited to practice my sleep coaching skills, I would interview every client that crossed my path at the sleep disorders centre. Early one morning, I was removing the electrodes from one of my charges and her husband appeared in the lab to chauffeur her home. She said with a smirk, “He should be the one in here not me.” I jumped at the opportunity to explore another person’s sleep challenges. He explained that he did not sleep all that well. I asked the standard battery of questions and ended with “How much coffee do you drink?” He was a cab driver and worked very irregular hours. He said “I drink 3 or 4 a day”.
I thought to myself “That’s not too bad, a little high, but not too bad.” I then asked “3 or 4 large or small cups of coffee?”
He looked at me confused and replied “No, not cups, pots”.
I gasped! “Sir, that’s not very healthy, how ever do you sleep?”
“It works OK, I just drink a bottle of rum before bed and I pass out,” he responded.
It is not too hard to understand that 3 or 4 pots of coffee and a bottle of rum a day might not fit with a healthy approach to sleep. But how much coffee is too much?
One of my sleep coaching rules is to remove as much caffeine from your diet as possible. I used to say all caffeine, but that just sets people up for failure. Caffeine is pervasive; it’s in soft drinks, pain killers, allergy medications, coffee, tea, chocolate, appetite suppressants, cough remedies, all sorts of food products, and now we even have full-power caffeinated energy drinks. I try to avoid caffeine wherever possible and in fact, my first exposure to the power of caffeine wasn’t until I was in high school. While working one evening at my part-time restaurant job, I heard about a waiter who had taken a bunch of “wake ups”. These caffeine pills pack a 100 milligram (mg) dose into one hit. This is roughly the same amount of caffeine in a strong cup of coffee and he took quite a few. Imagine drinking 4 or 5 cups of coffee within about 15 minutes. How do you think you would feel?
I had been interested in sleep and dreams for many years already and I was intrigued by the “wake ups”. I was working as a cook in the kitchen and I watched the waiter all night. He took the pills to combat fatigue, probably from too much partying knowing this fellow. At first, he was zooming around like some kind of super-server, but by the end of the shift, I am not sure if he even finished his full 6 hours, he was a sorry site. He was white as a ghost and nauseous. “Wake ups, not for me” I thought.
My next experience was with the precursor to today’s energy drinks, a can of soda called Jolt. I think it may still be around. The Jolt slogan was something like “all the sugar and twice the caffeine”. It was late Friday night and my school chums booked some ice time for 12:00 am to play co-ed broomball. I knew it would be difficult to stay energetic until 12:00 and a couple of us chugged back a few cans of Jolt. My heart raced, my head spun, and an upset stomach turned into nausea. Of course, anytime there are boys mixed with girls the machismo kicks in and instead of calling the night quits, I pushed on and made it through the broomball game. That was my last late night broomball game and my last can of Jolt.
Over the next 8 years, I learned how to consume caffeine properly. I had to work through at least three sleepless and over-caffeinated nights and the extreme fatigue caused by working many under-caffeinated graveyard shifts at the sleep disorders centre, but I became a full-fledged coffee drinking adult. It was never for the taste. I had to disguise the bitter nuttiness with mounds of sugar and buckets of thick heavy cream. It was always to fight fatigue. I learned how to combine sleep strategies and fatigue counter-measures with only ONE cup of coffee per day. That’s all I needed and realistically, if you are working nights, that should be all you need as well. Looking back now, I think it is cruelly ironic that I became an expert at titrating my caffeine because of my endless night work at the sleep disorders centre.
Part II: Coffee, from Counter-measure to Crutch
“Get off the caffeine altogether!” is what I used to tell my sleep coaching clients. If I can do it, you can do it. Truth be told, it wasn’t that easy for me either. After I learned that 5 cups of coffee in 1 hour makes it difficult to read and doesn’t really help with cramming for an exam, I reduced my intake to 1 cup of coffee for a whole night of studying. Later, when I was working nights at the sleep disorders centre, I would drink one cup at 2:00 am and it would keep me going until the end of the shift and if I timed it just right, it would not interfere with my daytime sleep. If I was working during the day, I’d have one cup of coffee with breakfast and I’d be fine for the rest of the day. I had come to enjoy the ritual, just enough low fat milk, a little sugar and some gentle sips of the steaming brew and I’d have a nice 15 minute escape before starting the day. The ritual started repeating itself in the afternoons and it was often accompanied by a creamy maple doughnut. Another nice 15 minute escape.
It had become more than a fatigue counter-measure, it was a source of pleasure. When I decided I wanted to reduce my sugar intake and live in a more relaxed state, the logical thing to do was to also stop the coffee. At first I tried decaf but this didn’t reduce my sugar intake. I decided I had to go cold-turkey.
In my sleep disorders centre days I was involved with assessing clients’ daytime sleepiness levels. You can tell a lot from the varying degrees of sleepiness. It can indicate sleep disorders such as narcolepsy and hypersomnia and tease out the role of depression in insomnia. It will even point towards whether or not a client is safe to drive or operate heavy machinery. During these assessments, clients were not allowed to take in any caffeine. They had to skip their morning java and avoid it all day. You could always tell the occasional users from the habitual. The occasionals, who would have 1 or 2 cups of coffee per week, would normally have no problems during the assessments. The habituals, who consume 1 or more cups per day, were always plagued by early afternoon headaches; and the more entrenched their caffeine use was, the worse their company became. By late afternoon, the happiest person would become the most cantankerous old sod you could imagine. Many a client threatened to leave before the assessment was completed, just to get their fix. But I knew it was not their fault.
Somehow I forgot about the effects when I decided to cut out sugar and go cold-turkey with the coffee. So the headaches and terrible feelings were a surprise, especially since I was only regularly drinking one cup per day. It took 2 days before I realized that I was feeling so crummy because I was no longer drinking coffee. Although it wasn’t that hard to stop drinking the coffee, it was hard not to reach for it again just to stop the headaches. I even had to fight the urge to take an aspirin because many analgesics have caffeine in them. One aspirin would put me right back where I started. Within a week I was feeling better and surprisingly energetic. Without the daily teaspoon of sugar, dollop of cream and doughnut, I even lost a few pounds.
I am still doing OK, but every now and then I’ll have a frothy cappuccino on a Sunday morning. One every couple of weeks doesn’t throw me off.
It’s not until I have a few coffees, maybe one a day for 2 or more days that the problems start. It’s usually Monday morning when I decide that I have to get back on track. I have come to expect the headaches, but the depression and flu-like feelings catch me off guard every time. It’s a nasty feeling. Very similar, I imagine, to having a perpetual low-grade flu along with a diagnosable depressive disorder. I don’t feel like doing anything except staring blankly at the TV or crawling back into bed; my body aches and I feel nauseous and have cold sweats. Life loses meaning, I don’t feel optimistic about the future, I feel sick and I withdraw. Talking to anyone is a chore and smiling is impossible. It’s usually about Wednesday that I realize “Darn I’ve done it again. I have reintroduced a steady stream of caffeine into my brain and then I’ve taken it away”. That’s when the depression lifts, the aches and pains subside and the headaches are long gone.
There is a very biological reason for all of this. It’s a process that starts with drug action and progresses from tolerance to addiction and on to withdrawal and sensitization. Most drugs follow this same progression. Caffeine is no exception, although not always classed as such, it is a drug. What happens with caffeine in particular is that it blocks the brain’s fatigue signal and tricks the body into feeling energetic.
Part III: Drug Action
The molecular structure of caffeine fits nicely into the neuronal receptors in the brain normally reserved for a neurochemical called adenosine. The brain releases adenosine when we are fatigued or our energy levels are low. Adenosine slows down the conversion of fat to fatty acid in order to conserve energy. Our muscles need the fatty acids for energy but when they are not as plentiful, the muscles slow down and go into relaxation mode. This slow down and relax mode makes it much easier to fall asleep and replenish our energy stores. But when you drink coffee, tea or cola, or eat a chocolate bar, the caffeine from the food blocks the adenosine from doing its work and your brain is unable to sense that your energy stores are low and you are fatigued. Instead, the naturally occurring stimulants in your brain continue to send the activity signal to your body and the slow down and relax mode doesn’t happen.
To paint a clearer picture, imagine a padlock securing the door to your bedroom. When you are tired you insert your key (the adenosine) and remove the padlock. You then open your bedroom door and find a comfy bed, warm pyjamas and some quiet relaxation music that help you to slow down and relax (that’s the adenosine working). After getting changed and lying down, you get some much needed sleep that restores your energy levels and you wake up refreshed and ready to go.
Now imagine something a little different. You’re feeling tired and on the way up to bed you have a cup of coffee. When you arrive at your bedroom door, you find that a key is already in the padlock (that’s the caffeine blocking the adenosine). You jiggle the lock a little to see if the key will fall out, but instead the hallway lights turn on and your children, or pets if you don’t have kids, come running out to greet you. They are happy, loud, full of energy and want to play (these are the naturally occurring stimulants), so you gladly start running in circles with them and you no longer feel tired.
In this manner, caffeine can work as a temporary measure to fight off fatigue. This is often referred to as a fatigue counter-measure. A properly timed cup of coffee can have a worthy effect.
Part IV: Tolerance
One of two things happens after you ingest caffeine. First, if you don’t ingest any more caffeine within about 48 hours, the caffeine will work its way out of your brain and stops blocking the adenosine. The fatigue system in your brain goes back to normal and properly signals when it is time to slow down, relax and go to sleep.
The half-life of caffeine is between 3 – 4 hours for most healthy adults who are not on any medications. Some oral contraceptives and other medications can extend the half-life to as much as 10 hours. With a half-life of 3 – 4 hours, your strong cup of morning coffee with a 100 mg dose of caffeine, will leave 50 mg of caffeine in your system 4 hours later. In 8 hours, 25 mg of caffeine will be in your system. When you are ready for bed 16 hours after your morning coffee, there will still be 6.25 mg of caffeine in your brain. Although this amount may not prevent you from sleeping, it can reduce the quality of your sleep, especially if you are caffeine-sensitive.
Not until 48 hours after your one cup of coffee will the dose have been worked down to 0.024 mg of caffeine. At this point the fatigue system in your brain will be almost back to normal and able to receive adenosine’s signal to slow down and relax.
The second scenario: If however, you ingest more caffeine before the fatigue system can normalize, your brain will make an adjustment. It will eventually realize that the fatigue system is not working properly and the slow down and relax mode is not happening efficiently. This of course will have detrimental effects on your sleep, the severity of which increases proportionately to the amount of caffeine you ingest. The brain’s adjustment is to create more receptors to receive the adenosine that was previously blocked out by caffeine. The new receptors readily accept the adenosine and the fatigue system is able to slow the body down again and allow sleep to occur in spite of the presence of caffeine. Albeit the sleep will never be as good as it is without any caffeine.
At this point, caffeine isn’t really helping you combat fatigue, you are consuming the caffeine but the effects are very much diminished. Your brain has become used to the having caffeine in its system. This is called tolerance and it can happen with as little as one cup of coffee per day. Your brain is tolerant of the caffeine and functions almost normally, albeit with some sleep decrements.
Part V: Addiction, Coffee can make you tired!
There is an argument over whether or not tolerance is a component of addiction and then of course there is the argument over whether or not psychological addiction is actually addiction. I am going to stay away from those debates and discuss physiological caffeine addiction as the next step that happens immediately after tolerance.
Caffeine tolerance means that your brain has come to expect a certain amount of caffeine at certain times of the day. It means that your brain has physically changed in order to accommodate your daily dose of caffeine without having a dramatic effect on your energy level. Whether it be 1 cup of coffee or 4, your brain now needs the caffeine. If it doesn’t get it, all of those previously blocked adenosine receptors will be open and receiving a rush of adenosine sending your body into a deeply fatigued state. It’s like this….if there were only 10 receptors in your brain with 5 of those normally blocked by caffeine and the other 5 open for adenosine, and if you don’t replenish your caffeine stores, the caffeine will be used up by the adenosine receptors. When the fatigue system starts to pump out adenosine, all 10 receptors would be receiving adenosine. That’s twice as much adenosine working on the system and resulting in twice as much fatigue than usual.
So what do most coffee drinkers do when they feel tired during the day? They drink more coffee. This plugs up the adenosine receptors again. In turn, the brain makes more adenosine receptors to restore balance to the fatigue system. It then takes even more caffeine to keep the fatigue away and, eventually, without a constant supply of caffeine to keep the receptors blocked, you remain in a perpetually fatigued state. That’s how coffee can make you tired and that’s caffeine addiction.
Caffeine addiction also comes with a larger set of symptoms than include:
- Muscular tension
- Pain and discomfort
- Sexual difficulties
- TMJ dysfunction
- Cold hands and feet
- Poor life quality
- Stomach cramps
- Heart palpitations
- Chiropractic problems
- Increased reliance on other addictive substances such as tobacco and alcohol to reduce the stress feeling caused by caffeine
These symptoms make sense given that caffeine stops your brain from entering a relaxed state. It’s like your brain and body are stuck in a chronic fight or flight state. This feeling can persist long after you have withdrawn from caffeine. This is due to a psychological conditioning process that links small life stressors with large stress reactions. While on caffeine you will often react strongly to small life stressors. You really have no choice. Caffeine keeps you in a stressful fight or flight state and when you add in a little life stressor to an already stressed person they react irritably, angrily or aggressively. If you pair little life stressors with a stressful reaction often enough, your body and brain learn that this is the way they are supposed to react. Take the caffeine out of the equation after the conditioning has occurred, and you’ll still react poorly to little life stressors. For some people, the conditioning fades away, others need to work at it consciously by practicing relaxation exercises and mood management.
Part VI: Withdrawal and Sensitization
Remember those crummy feelings I described earlier? – headaches, depression, flu-like aches, pains, nausea – these are the symptoms of withdrawal.
When coming off the caffeine, expect these symptoms along with irritability, and difficultly just getting through the day. How long these symptoms last depends upon a whole lot of factors. For most people, their brains will adapt backwards and close off the additional adenosine receptors within two-weeks. But if you have been drinking coffee for a long time, consuming large amounts of caffeine, and are in poor health, it’s going to take longer than two weeks for your brain to normalize and for you to feel more relaxed during the day and sleep better at night.
These two weeks can be hard, luckily though the magnitude of the disruption decreases as the time passes. So with every passing day, you will feel better and better. Many people will slip up during the withdrawal stage and sneak a cup of relief. Consuming any caffeine at this point is worse than an addict drinking coffee daily because it occurs during a period of sensitization. This is when your brain is really craving the missing elixir. All of the receptors are wide open and hoping to get a hit. Then with one small dose of caffeine the brain can become euphoric in a way.
I know first hand…I have snuck in a coffee here and there during the sensitization phase and felt wonderful. It’s like coffee was the missing link between me and bliss. My mind raced and was full of wonderful new ideas; I felt wildly creative and filled with enough energy to light a room. It was great…the problem is that it turns ugly. Like the cuddly puppy who sinks his pointy new teeth into your arm, sensitization makes you feel great and then smacks you down to a new low. The crash is hard. Fatigue, diarrhea and heart palpitations are common symptoms of the sensitization crash and they make it difficult to stay off the caffeine. The addict knows the short term solution is a big hot cup of coffee. When your brain is in the sensitization phase, it is much more responsive to caffeine and it amplifies the reaction to even a small amount. The effects are similar in hardcore drug addicts. When marijuana and amphetamine users stop taking the drugs for a short time and then start again before their brains have normalized, they will feel even more high than when they were regularly using. Of course for the hardcore drug user and the coffee drinker alike, the pleasure they experience during the sensitization phase can get them hooked again and stuck right back where they started.
Part VII: The Sleep Coach’s Perspective
I mentioned earlier in this article that I used to tell my clients to cut all the caffeine out of their diets immediately. Well you can imagine the reluctance to do so if coffee was the only thing to keep you hanging on through a sleep problem.
I believed back then and still believe that sleep should rejuvenate you and not caffeine. Think about it for a minute. You lie there for 6 to 8 hours a night to top up your energy stores and then you down a cup of coffee in the morning to get yourself going. It shouldn’t work that way. Sleep should give you the energy you need. If you are not waking up and feeling OK within about 90 minutes of waking, then it’s time to look into your sleep. At this point it is also a good idea to examine your caffeine levels.
I know it’s really hard to cut out caffeine altogether and I now have my clients slowly work down to one small dose of caffeine per day, usually 1 cup of coffee. I suggest that they drink their coffee or eat their chocolate before 10 am. If you do this, there will still be over 6 mg of caffeine in your brain at bedtime. All going well, this won’t have an effect on your sleep. If you are still having trouble sleeping or your sleep does not feel deep and restful, then you might be sensitive to caffeine, in which case you have a decision to make. Sleep better, feel more relaxed and function better all day by cutting out all caffeine or trade all of this for a 20 minute indulgence as you sip on your morning Jo. Hard choice isn’t it?