[geeks] caffeine - differences based on source

[nate at portents.com]

> Plus, as others have mentioned here, the fact that teas usually
> contain other stimulants as well would further add to the long-
> lasting, smoother effect that they have.

It should also be mentioned that a lot of other things can affect how the
body metabolizes caffeine.  The birth control pill for women can cause
caffeine to be metabolized up to twice as slowly, greatly prolonging the
effects.  Smokers on the other hand metabolize caffeine about two times as
fast as people who don't smoke.  I don't know what the effects of the pill
and smoking are on metabolizing the other stimulants in teas, though. 
Needless to say, between all the various compounds and all the things that
could possibly affect how a body deals with them, there are a lot of
variables involved.

- Nate