Imma Perfetto
Cosmos science journalist
New Australian research suggests that heavy coffee drinkers could use decaffeinated coffee as a way to kick their caffeine habit.
Researchers have discovered that decaf quenches caffeine withdrawal symptoms – such as headache, fatigue, bad mood, and irritability – regardless of whether the drinker knew it was decaf or not.
“A convincing cup of decaf has the power to reduce withdrawal symptoms a lot when the person drinking it is unaware it’s decaf. But our study suggests that even if they are aware it’s decaf, their withdrawal still subsides,” says Dr Llewellyn Mills, a senior research associate at the School of Addiction Medicine at the University of Sydney, and first author of the study in the Journal of Psychopharmacology.
The study involved measuring the withdrawal symptoms of 61 heavy coffee drinkers (Three or more cups of joe per day) who were asked to forego caffeine for 24 hours.
Participants were then separated into three groups: one was told it was drinking decaf (the truth), another told it was drinking regular coffee (a lie, it was still just decaf), and the third control group was given water.
Then, 45 minutes later, they were asked to rate their withdrawal symptoms again.
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“The group we lied to reported a big drop in caffeine withdrawal even though there’s no pharmacological reason why it should. Because they expected their withdrawal to go down, it did go down,” says Mills.
“In other words, a placebo effect. We’ve found this in several studies now.
“What was interesting is that withdrawal symptoms also reduced even when people knew they were getting decaf. Not as much as the group we lied to, but a significant amount.”
This is what’s called an open-label placebo effect, where the effect happened even while knowing they were getting a placebo.
Participants were asked to rate how much they expected various drinks to reduce their caffeine withdrawal before being given their beverages.
“Funnily enough, they actually expected water to reduce their withdrawal more than decaf,” says Mills.
“Withdrawal in the group we gave water to didn’t drop at all, whereas the people who were given decaf experienced a significant reduction.
“The reduction they experienced was contrary to what they expected would happen when they were given water and decaf.”
Mills says that the increase in alertness and energy people feel when drinking their daily coffee is just caffeine withdrawal being reversed.
“A cup of decaf could help someone who is trying to cut back their caffeine intake to temporarily ride out the worst of the cravings and help them stay caffeine-free,” he says.
“We did this study to model some of the processes involved in addiction to any drug, including more serious, or harmful, drugs. What we found has some promise for developing new treatments for addiction that integrate placebo effects.”