Waiter, waiter, percolator

High society - Health - Specials - smh.com.au

I had no idea that the levels of caffeine from espresso could be so wildly different:

Unless you drink instant coffee, it is impossible to control your caffeine intake if you're a regular coffee drinker. A Griffith University dietitian, Ben Desbrow, proved fresh coffee has wildly inconsistent content by buying 97 espressos, the base unit of coffees, from Gold Coast cafes and analysing the laboratory results. Some coffees contained up to nine times more caffeine than others; from 25 milligrams up to 214 milligrams.

The finding underscores a nightmare that caffeine scientists have long faced when trying to find out whether caffeine is beneficial, detrimental or neutral for, say, cardiovascular disease, cancer or diabetes. Researchers need to be able to measure a population's caffeine consumption as a starting point. But, as Desbrow demonstrated, recalling how many cups of coffee you consume a day is a dodgy and probably useless gauge. This cornerstone problem could be dissuading scientists from the area and leaving coffee addicts in the dark.

And the reason this may be a problem:

It is generally accepted that stress or edginess and other harmful effects of caffeine can kick in after an intake of 400 milligrams a day, so an unsuspecting person drinking three cups of high-caffeine coffee across the day could easily be in the danger zone without realising.

Sounds like caffeine addiction could be a much bigger problem than I would have expected, all depending on where people buy their coffee from.