My colleagues and I have just had a blazing row, sorry, discussion; concerning the amount of coffee I drink. (Too much!) My stand is that I don't smoke, hardly drink and eat healthily, so I'm having my coffee! My colleagues' contention is; that amount of caffeine must be bad for you. I've had a search and found some good sources of information, Caffeine Content , Is caffeine a health hazard? , and a great 'T' shirt design - t shirt.
As far as I can tell, the health risks are balanced by the benefits, and I think we all do more hazardous things between drinks.
I wondered if anyone else had any views, as I don't know any engineers who don't drink coffee!