Saturday, December 6, 2008

Death by Caffeine

I drank a wonderful cup of hot chocolate this evening while watching a nice Christmas movie with my wife and children. Now, I sit here at my computer at 1am wondering why I am not tired. . . and I realize it is the caffeine ingested with that wonderfully smooth and chocolaty hot cocoa. This got me to wondering . . . how long is this going to be in my system?



Well, the half-life of caffeine is about 6-8 hours. That means it takes up to 36 hours for your body to metabolize the caffeine and remove 95% of it from your system and it takes another 36 hours to completely remove it. Will I still be sitting here on my computer in 6 days? I hope not.


Caffeine is metabolized or broken down in the liver by the cytochrome P450 oxidase enzyme (This is the same metabolic component important in steroid synthesis) system into three metabolic dimethylxanthines, which each have their own effects on the body:
Paraxanthine (84%): Has the effect of increasing lipolysis, leading to elevated glycerol and free fatty acid levels in the blood plasma.
Theobromine (12%): Dilates blood vessels and increases urine volume. Theobromine is also the principal alkaloid in cocoa, and therefore chocolate.
Theophylline (4%): Relaxes smooth muscles of the bronchi, and is used to treat asthma. The therapeutic dose of theophylline, however, is many times greater than the levels attained from caffeine metabolism.
Each of these metabolites is further metabolized and then excreted in the urine.


The interesting effect of all this is that caffeine secondarily stimulates insulin secretion which then lowers blood sugar, thereby stimulating hunger. This can cause weight gain. Caffeine, inhibiting the Cytochrome P450 system also can effect steroid synthesis and can lead to lower testosterone levels and weight gain. Funny isn't it? Caffeine sold in all the weight loss products has just the opposite effect on weight - it will cause you to gain weight.


So, how much caffeine is really problematic? Well, physicians use caffeine to help with fatigue and to help with cognition (your ability to think clearly). However, only 100-200mg are needed to have these effects. The precise amount of caffeine necessary to produce effects varies from person to person depending on body size and degree of tolerance to caffeine. It takes less than an hour for caffeine to begin affecting the body and a mild dose wears off in three to four hours. Consumption of caffeine does not eliminate the need for sleep: it only temporarily reduces the sensation of being tired.


250-700mg of caffeine in your system can, and often does, cause anxiety, nervousness, hypertension, and insomnia (you are probably reading this at 1am because of your hot chocolate, too, aren't you!?) Caffeine relaxes the internal anal sphincter muscles and thus should be avoided by those with fecal incontinence. (I now understand why they never serve caffeinated drinks at and open house for a proctologist).


Caffeine has a drastic effect on spiders as you can see. The picture is the same spider "caffeine free" on top and "caffeinated" on the bottom.


Greater than 1000mg of caffeine will often cause tachycardia (rapid heart rate over 110 bpm), heart palpitations (the sensation of your heart pounding or beating heavily in your chest), insomnia, tinnitus (ringing in the ears), cognitive difficulty (cloudy thinking).


How much caffeine is too much? Well, over 10 grams is lethal. Yes, caffeine can kill you . . . literally.


So how much caffeine did I get in my cup of hot chocolate? Well, I drank about 10 oz and that contains roughly 0.6mg per oz. I don't drink caffeine very often and so that 6-7mg is actually affecting me and has given me a short burst of energy (not to mention the sugar content of the hot cocoa - that's for another nights blogging). Here's a list of common drinks and their caffeine content, just in case you wanted to know:


Amount/ Product/ Caffeine content:


12 oz Most cola drinks. . . . . . . . . . . . . . . . . .40-100mg

8 oz Hot Cocoa . . . . . . . . . . . . . . . . . . . . . . . .5mg

1 cup Espresso. . . . . . . . . . . . . . . . . . . . . . . .200mg

6 oz Coffee (American). . . . . . . . . . . . . . . . .100mg

1 cup Instant Coffee . . . . . . . . . . . . . . . . . . .75mg

1 cup Decaff Coffee. . . . . . . . . . . . . . . . . . . . 3mg

16 oz Rock Star. . . . . . . . . . . . . . . . . . . . . . . 300mg

1 cup Starbucks Grand Coffee. . . . . . . . . . .360mg

1 cup Tea. . . . . . . . . . . . . . . . . . . . . . . . . . . . 60mg

4 oz Chocolate bar. . . . . . . . . . . . . . . . . . . . .80mg

1 Excedrin. . . . . . . . . . . . . . . . . . . . . . . . . . 65mg

1 Midol . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .32mg

1 No-Doz. . . . . . . . . . . . . . . . . . . . . . . . . . . . .100mg



Well, for what it is worth, I think I will save my next cup of hot chocolate for next Christmas.

I am going to go find the Benadryl . . . right after I find the bathroom . . .

1 comment:

Kendra said...

Thanks for the info. That is really good to know, and is something I have been wondering about.