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A study found that high quality decaf coffee can help ease caffeine withdrawal symptoms. Pixel Stories/Stocksy
  • Good decaf reduces symptoms of caffeine withdrawal in a new study.
  • Whether participants believed they were drinking standard coffee or decaf after 24 hours without coffee, they felt better afterward.
  • The study is an interesting addition to research regarding surprising placebo effects.

According to a new study, if a cup of decaffeinated coffee tastes sufficiently like real coffee, it may be able to reduce the unpleasant symptoms of caffeine withdrawal.

Researchers at the University of Sydney found that a cup of high quality decaf significantly reduced the withdrawal symptoms participants had been experiencing 24 hours after their last cup of caffeinated coffee.

Some individuals in the study were unaware that they were drinking decaf, while others knew what they were drinking. Interestingly, withdrawal symptoms also receded in the group who knew what they were imbibing.

The study is one of many describing the often-surprising beneficial effects that placebos produce in clinical studies.

A placebo is a substance with no therapeutic effect, often administered to some participants in a controlled drug study. Other participants receive the actual drug being tested. The placebo-receiving control group provides baseline measurements against which researchers can assess the drug’s effect on those who have received it.

Participants sometimes gain the expected benefits of drugs being tested when they do not know they’ve been given a placebo.

In other studies, the placebo effect also occurs in participants who receive “open-label” placebos — that is, they have been told that they were getting a placebo.

The University of Sydney study may offer a means of escaping caffeine addiction for those who want to quit drinking coffee.

The study appears in the Journal of Psychopharmacology.

Americans love coffee. According to market research company DriveResearch, three out of four Americans drink coffee daily, and 49% drink three to five cups daily.

Many depend on caffeine’s jolt of energy and credit its caffeine with making them more alert and focused. Research suggests, however, that coffee may offer much more than this. It may also lower your risk of type 2 diabetes, heart failure, colon cancer, Parkinson’s disease, and Alzheimer’s disease.

The Food and Drug Administration (FDA) recommends consuming no more than 400 milligrams of caffeine daily, or the amount in about four to five cups of coffee.

Caffeine is also an ingredient in tea, energy drinks, and sodas. According to the FDA, it is both a food additive and a drug.

While caffeine is not technically addictive, quitting coffee can result in withdrawal symptoms, including headaches, fatigue, sleepiness, irritability, depression, scattered concentration, nausea, and muscle pain or stiffness.

These symptoms were reduced or alleviated by decaf in the new study.

“A convincing cup of decaf has the power to reduce withdrawal symptoms a lot when the person drinking it is unaware it’s decaf,” the study’s lead author Dr. Llew Mills tells the University of Sydney News. “But our study suggests that even if they are aware it’s decaf, their withdrawal still subsides.”

Dr. Mills told Medical News Today that decaf should work as long as it “does not taste like decaffeinated coffee.”

For the study, researchers used a U.S. brand called Major Dickason’s. “Despite Sydney folks being notorious coffee snobs, our participants were pretty easy to trick,” Dr. Mills said.

For the study, 61 heavy coffee drinkers used to three or more cups a day took a 24-hour break from consumption. At the end of that period, participants filled out a withdrawal-symptom questionnaire.

Researchers divided the individuals into three groups. One group was under the impression they would be drinking coffee, and one group was told they would be drinking decaf. The third, which was the control group, received water.

Forty-five minutes after downing their beverage, participants again filled out the questionnaire.

“The group we lied to had a sizable reduction in their caffeine withdrawal,” said Dr. Mills. “But surprisingly, the group we told the truth to also reported a reduction in their caffeine withdrawal, although not as large a reduction as the group we lied to.”

According to Harvard Medical School’s Dr. Ted Kaptchuk, a leading investigator of placebo effects who was not involved in the study:

“It provides a proof-of-principle that honest decaf coffee used as [an] open-label honest placebo can serve as an aid to reducing withdrawal symptoms, at least in the very short time frame [45 minutes] of the study.”

About the symptom reductions for the group of participants who knew they were drinking decaf, Dr. Kaptchuk noted:

“Importantly, expectations were not involved with this decaf effect, which supports long-term clinical research on clinical patients that expectations are not a component of honest placebo effects.”

Dr. Mills also cautioned:

“I think it would be a mistake to discount the role that cognition and learning can play. It is certainly not out of the realm of possibility to think they could have a robust conditioned response to the stimuli surrounding caffeine consumption even in the absence of expectancy.”

As Dr. Kaptchuk explained:

“The mechanism of open-label placebo probably involves the body automatically and non-consciously reacting to the embodied ritual of coffee-taking that makes the central nervous system — in some people some of the time — respond with similar reductions of symptoms as if it was taking a real cup of coffee.”

“This process in neuroscience,” said Dr. Kaptchuk, “is called ‘prediction coding’ (also called ‘Bayesian Brain’) and is acknowledged as critical for symptom formation.”