As many regular coffee drinkers know, mild headache, a weary feeling, and some loss of alertness can occur when we stop drinking caffeinated coffee for any length of time. But, what happens when you go back to drinking coffee or switch to decaf or stop drinking it altogether??? According to a recently published study by researchers from the University of Vermont and Johns Hopkins University, once you've been on a daily steady caffeine dose for a couple of weeks, tolerance essentially develops and your brain and mood look almost like they would if you were not a caffeine user at all. This was unexpected data that resulted from the study. Researchers sought to investigate the biological mechanisms of caffeine withdrawal by looking at brain electrical activity and blood flow during caffeine withdrawal to examine what was taking place physiologically during acute caffeine abstinence, including the likely mechanism underlying the common caffeine withdrawal headache.?? They confirmed via a rigorous, double-blind study that caffeine withdrawal does indeed result in changes in three areas: cerebral blood flow (flow of blood to the brain) as measured by ultrasound, brain electrical activity as tested by an EEG (electroencephalogram), and participant self-reports of subjective effects.
As many regular coffee drinkers know, mild headache, a weary feeling, and some loss of alertness can occur when we stop drinking caffeinated coffee for any length of time. But, what happens when you go back to drinking coffee or switch to decaf or stop drinking it altogether?
According to a recently published study by researchers from the University of Vermont and Johns Hopkins University, once you've been on a daily steady caffeine dose for a couple of weeks, tolerance essentially develops and your brain and mood look almost like they would if you were not a caffeine user at all.
This was unexpected data that resulted from the study. Researchers sought to investigate the biological mechanisms of caffeine withdrawal by looking at brain electrical activity and blood flow during caffeine withdrawal to examine what was taking place physiologically during acute caffeine abstinence, including the likely mechanism underlying the common caffeine withdrawal headache.
They confirmed via a rigorous, double-blind study that caffeine withdrawal does indeed result in changes in three areas: cerebral blood flow (flow of blood to the brain) as measured by ultrasound, brain electrical activity as tested by an EEG (electroencephalogram), and participant self-reports of subjective effects.
During acute caffeine withdrawal, participants experienced the typical symptoms of headache, fatigue and lack of alertness which were reflected in the physical examinations. In the brain, the researchers saw increased cerebral blood flow velocity, increased EEG theta power (a mechanism reflecting increased drowsiness), and decreased beta power (reflecting decreased alertness) -- the likely mechanisms that underlie the subjective symptoms of withdrawal.
Participating in the carefully controlled study were 16 people who were regular caffeine users who ingested capsules daily that contained either caffeine (400mg/day, approximately 3-4 cups of coffee) or placebo. Neither participants nor staff knew the capsule contents throughout the study.
Unexpectedly, the researchers also discovered that there were no differences in blood flow velocity, electrical activity in the brain or subjective effects between those participants were maintained on chronic placebo vs. those who were stabilized on chronic caffeine administration.
Participants reported they simply did not feel any more alert, energized, happy, awake or any other attribute that might be expected when consuming caffeine regularly, and they essentially felt similar to how they had felt when they had been off of caffeine for several weeks.
This means that, contrary to what most of us coffee lovers would expect, we found no evidence that there are net beneficial effects associated with habitual or prolonged caffeine administration, at least on the measures we examined," said Dr. Sigmon.
The study results were published in the recent issue of the scientific journal, Psychopharmacology. Authors included Dr. Sigmon, research associate professor of psychiatry at the University of Vermont; Roland Griffiths, Ph.D., Johns Hopkins University School of Medicine Departments of Psychiatry and Neurosciences, and Ronald Herning, Warren Better, and Jean Cadet of the National Institute on Drug Abuse's Molecular Neuropsychiatry Section, Division of Intramural Research.?