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More than half of American adults drink coffee every day, according to the National Coffee Association. The caffeine in coffee has well-known stimulant effects, including increased alertness, attention, and wakefulness. But recent research suggests that the strength of your response may be shaped in part by your expectations. The more you expect a java jolt, the more likely you are to get one.
Wake Up and Smell the Research
A 2011 study by researchers from the University of East London, published in the journal Appetite, is a case in point. In the study, volunteers did better on a test of attention when told they were drinking caffeinated coffee, regardless of whether they were actually drinking regular coffee or decaf. The belief that they were consuming caffeine, whether true or not, also affected their mood and responsiveness to reward.
In short, part of their reaction to caffeine was apparently due to the placebo effect. This is the same phenomenon that leads participants in medical studies to feel better even when given a sugar pill or sham treatment, simply because they believe that they will. Not incidentally, the volunteers in this study all had at least a two-cup-a-day coffee habit. They had probably come to expect a pick-me-up from coffee - and their minds made sure that they got it.
Another new study, this one by researchers from American University in Washington, DC, offers indirect support for that idea. The study included more than 1,000 adults, coffee drinkers and non-drinkers alike. The researchers found that greater caffeine intake was associated with higher expectations that it would boost energy and alertness, suppress appetite, improve mood, and enhance athletic performance.
This suggests that frequent coffee drinkers may be particularly primed for the placebo effect based on their past personal experience. As with other drugs, social learning about caffeine also influences how people feel when they use it. Both observations of other coffee drinkers and societal beliefs about caffeine add to the expected effect.
The Caffeine-Free Caffeine Buzz
Personally, I'm not a coffee drinker, but I do love my diet cola. (Little-known fact: Diet colas tend to contain slightly more caffeine than their non-diet counterparts.) I swear that I feel the same small energy boost whether the diet cola is caffeine-free or not. Is it all in my mind? Probably. But that doesn't make the extra alertness any less real.
The psychological effect may be magnified if you drink coffee, which contains considerably more caffeine than a cola does. The greater kick may set up a powerful expectation for how you'll feel after your next piping hot cup o' joe - so powerful that you might still get a caffeine buzz even if you wind up drinking decaf.
Linda Wasmer Andrews is a health writer and recovering diet cola addict. Follow her on Twitter. Find her on Facebook. Visit her online.
