Like an addict who can't get a buzz without blowing through a $500 pile of powder, frequent caffeine users are victims of their own familiarity with their fix of choice.
"The medium/high caffeine consumers who received placebo reported a decrease in alertness and an increase in headache, neither of which were reported by those who received caffeine. However, their post-caffeine levels of alertness were no higher than the non/low consumers who received a placebo."
Hilariously, the house scientist for the British Coffee Association pops up near the end of the article to stick up for coffee's alertness-enhancing properties, adding:
"Coffee when consumed in moderation, four to five cups per day, is safe and may confer certain health benefits, including contributing to your daily fluid intake."
Ah, the healthy joys of moderate coffee drinking, hereby described as about a quart of the stuff daily.
If all this puts you in a foul mood, peruse The Oatmeal's excellent 15 Things Worth Knowing About Coffee. This plus a quart of java should be enough to distract you from the ugly truth about the stuff.
Image source: CHOW.com