Chances are, you have some caffeine in your system right now; you might even be reading this article with a cup of coffee, a can of soda or a mug of tea in hand. But how much do you know about the drug -- and yes, it is a drug -- you're consuming? Before downing one more gulp of your favourite stimulant, let go of some persistent, caffeinated myths.
1. We consume more caffeine than ever
With a Starbucks on every corner; grocery coolers full of soft drinks, energy drinks and teas; and convenience-store counters displaying 5-hour Energy shots, it seems that we are more caffeinated than ever.
Except we aren't. U.S. coffee consumption peaked 65 years ago, then fell dramatically. From 1946 to 2005, it declined roughly by half, from 46 gallons per person each year to 24 gallons. And despite the abundance of new ways to consume caffeine, we still get most of our caffeine from coffee. Two recent surveys, one by the Food and Drug Administration and one for an industry-backed research group, show that coffee accounts for two-thirds of the caffeine in the American diet.
As coffee drinking fell, soft drink consumption surged, rising from 11 gallons per person annually in 1947 to 51 gallons in 2005. But, with their lower caffeine content, soft drinks have not replaced the caffeine we've dropped from our diets by drinking less coffee.
That's something to bear in mind the next time you hear phrases like "In our hyper-caffeinated society..."
2. Energy drinks have more caffeine than coffee
Not really. Let's start with the classic Red Bull. The original 8.4-ounce can has 80 milligrams of caffeine. That's equivalent to a mere four ounces of drip-brewed coffee from Starbucks.
Cans of the super-size energy drinks such as Monster and Rockstar are twice the size of the little Red Bulls, with roughly twice the caffeine. At this serving size, the drinks begin to approach the caffeine levels of coffee. One analysis found an average of 188 milligrams of caffeine per 16-ounce cup of coffee. A can of Monster contains 184 milligrams.
But even these larger energy drinks don't approach the caffeine levels of Starbucks coffee. Starbucks claims approximately 260 milligrams of caffeine per 12-ounce cup of drip-brewed coffee ("tall") and 330 milligrams per 16-ounce cup ("grande"). Few energy drinks approach the latter level, which equals four Red Bulls. A 22-ounce bottle of NOS, an energy drink bottled by Coca-Cola, does contain 220 milligrams of caffeine. That is a lot, but an equal-size serving of Starbucks coffee would have twice as much.
Bottom line: If you want a strong caffeine jolt, stick to the joe.
3. Caffeine is a diuretic
Anyone who has slammed a large cup of coffee and then been stuck in a traffic jam may conclude that caffeine is a diuretic. But University of Connecticut researchers studied the effects of caffeine on healthy, active men in 2005 and found no indication of such an effect. Their study, which followed subjects for 11 days of controlled caffeine consumption, came to this conclusion: "These findings question the widely accepted notion that caffeine consumption acts chronically as a diuretic."
Because caffeine has been considered a diuretic, people have worried that drinking coffee can contribute to dehydration. In a study published this year, however, researchers in England looked specifically at caffeinated coffee. Their subjects were 50 men who consumed similar amounts of coffee or water while researchers measured their urine output. The result? No dehydration.
The authors say it's time to bust the dehydration myth: "These data suggest that coffee, when consumed in moderation by caffeine habituated males contributes to daily fluid requirement and does not pose a detrimental effect to fluid balance. The advice provided in the public health domain regarding coffee intake and hydration status should therefore be updated to reflect these findings."
It may be little comfort to that bursting bladder, but caffeine isn't to blame.