SAST Wingees

Insomnia, Sleep Patterns and Coffee

Updated Oct 17, 2006: with accurate reference links

As I said before I was down with a viral fever a month and a half back. Since I recovered I started noticing that I was not able to sleep at all. Its a very strange thing because I am the type that starts sleeping almost as soon as I hit the bed. At first, I attributed this to a side effect of the viral fever. .But since the sleeplessness was continuing I had to figure something out  Then I remembered something – about 7-8 years ago, myself and Priya Raju made an observation that if we drink coffee after 6PM we couldn’t sleep that night. So 7-8 years ago we stopped having coffee after 6PM. I’m now on the verge of turning 40 and I thought maybe I’m hitting another milestone in ageing effects.  So i decided to cut my afternoon coffee. I tried that for a few days but that didn’t seem to have an effect. Last week I was talking to one of my friends and she actually told me she couldn’t have coffee after 11am. I took her advice and for the past 2 days I have stopped having coffee after 11 am and I have made significant progress in my fight against sleeplessness. Now you are beginning to wonder I am sure, as I was, as to what is the connection. We all know that caffeine is a stimulant but for it to have an effect after so many hours is a bit puzzling. For us to understand that we need to understand a bit more about sleep. Sleep is an extremely complex subject and we as humanity don’t yet know a lot about sleep. But we have made some significant progress in our understanding of sleep. There is a particular aspect of sleep that seems to be connected to coffee –
During the day as our body metabolism works its magic to give us the energy it produces an important by-product called adenosine (adenosine if you recall is a key part of Adenosine Triphosphate (ATP) and Adenosine Diphosphate (ADP) which are energy molecules for want of a better term). This adenosine level keeps building up and reaches a certain upper threshold level after which you start sleeping. When you are sleeping an enzyme called adenosine deoxidase deaminase (ADA) goes to work and slowly reduces the adenosine levels and when it reaches its lower threshold level you wake up refreshed.  As you can see, these threshold levels are likely to be different for different individuals and may be determining the individual sleep pattern. I say maybe because as I said before sleep is a complex subject and there maybe many more aspects that govern it. Now the connection to coffee – the caffeine in coffee binds to adenosine receptors (which determine the adenosine levels) and fools the brain into thinking that the adenosine levels are still low. That’s why sometimes you maybe feeling tired but cannot sleep because of the effects of coffee. I would love to hear from people as to their experiences with coffee.  References:
1. An article in the New Scientist magazine ($$) which described the adenosine aspect I mention above.