Δευτέρα, Ιουνίου 27, 2005

Stopping coffee







I usually don't wish to talk about myself in this page. I prefer to present things that I consider interesting. In this case, however, I'll make a small exception, in the hope that my experiences will be of value to some of you.

During the last year I increased my caffeine intake considerably. I was serving in the army and I had to wake up at 05:50 - 06:30 or stay up during the night. Caffeine did help. Besides the actual pharmacological effect--which may gradually diminish--the enjoyment of small pleasures, like coffee, is sometimes psychologically indispensable. Now that I enjoy considerable working freedom (being a Ph.D candidate can be beneficial for your sleep habits, especially if you prefer staying up late instead of waking up early) I decided to gradually reduce my caffeine consumption.

(you may safely skip the following 4 paragraphs if you have no interest whatsoever in the biological properties of caffeine and similar molecules)

The caffeine molecule is a methylated purine that bears some relation to DNA bases and energy storage molecules like ATP. The broad class of methylated xanthines (kind of purine) includes several variants that can be found in natural (and not-so-natural) sources.

It is a lesser known, but true, fact that caffeine renders cells sensitive to DNA damage, especially from ionizing radiation (see here and here, for example). This is usually of interest in cancer radiotherapy, but the effect also occurs in normal cells. This raises the question of whether caffeine increases the susceptibility of normal cells to DNA damage, mutations and cancer. Fortunately, there is absolutely no indication to support this idea. Surprisingly, some studies even indicate that caffeine may decrease cancer risk in healthy individuals.

On the other hand, increased caffeine intake does increase fat metabolism and reduce appetite and may help during weight loss. It also improves athletic performance, which is why it is a controlled substance (high levels in athletes are considered "doping"). The relevant bibliography is very, very confusing because many "weight-loss" drug companies sponsor studies of dubious quality that get published in low-impact journals (impact factor is a rough measure of the credibility of a journal, as evidenced by the number of publications that refer to this journal). As a general rule, increased caffeine intake cannot be routinely recommended as a way to promote weight loss because of significant side-effects, although it might work for some people. The exact mechanism is not entirely clear at this moment.

Finally, another, significant effect of caffeine ingestion is the induction of anxiety. Caffeine consumption over 200mg/d can be a major cause of anxiety for some people and should be evaluated in all people that present with symptoms related to anxiety.

All the above being said, I must admit that I enjoy a good cup of coffee and I don't consider this to be particularly bad for health (in moderation, of course). I usually drink high quality espresso that I prepare at home with a nice Krups espresso machine. Its caffeine content, when prepared with Arabica coffee is quite low and the flavor is excellent. As a side note, I don't like complicated hot-drinks based on coffee (double extra latte frappuccino with whipped cream is nice, but it isn't coffee by my definition.)

Anyway, I decided to reduce my daily double espresso ritual to 2-3 espresso shots per week. At first I had a constant headache, especially at the back of my head. This was quite annoying but not strong enough to make me want an aspirin or paracetamol. The other weird effect was the deregulation of my sleep hours. I didn't sleep more, I just slept at odd hours. I could fall asleep at 16:00, wake up at 20:30 and then sleep again at 05:00. It seems that my insistence on drinking coffee strictly in the morning had conditioned my brain to accept this as "wake-up time".

A few days later, my headache is gone and my sleep is generally back to schedule. Most importantly, I can get up almost at any time with very little difficulty. Waking up is much more painless now that I don't need coffee to get me going. I simply open my eyes, stand up and I am completely awake and ready. My athletic performance has dropped a little bit (~5-8%) judging by my average cycling speed, but it's hard to provide an accurate estimate because the wind and the ambient temperature vary a lot these days. Not that it matters much, since I don't really compete with anyone. (and, of course, I can always drink coffee if I feel the need for speed).

PKT