- Researchers compared the neurological effects of coffee and caffeine consumption.
- They found that coffee, but not caffeine consumption increases brain activity linked to visual processing and higher-level cognitive function.
- The findings mean that some key benefits of drinking coffee may not be related to caffeine.
Could your morning cup of coffee be a placebo when it comes to boosting alertness and performance?
That may be the case, according to a new study that compared the effects of drinking coffee vs. consuming caffeine only.
Many people drink coffee first thing in the morning to overcome fatigue, stay alert and work effectively. Around
The study’s findings appear in Frontiers in Behavioral Neuroscience.
While much is known about the neurochemical effects of coffee on the brain, less is understood about its psychological effects.
For example, some research shows that while coffee may affect cognitive performance in non-habitual drinkers, it has less effect on habitual drinkers as they develop a tolerance.
The same research suggests that a large part of coffee’s and caffeine’s invigorating effects may be explained via the reversal of withdrawal symptoms from short periods of abstinence.
Further research into how coffee affects the brain could improve understanding of what motivates people to drink it.
Recently, researchers compared fMRI data from habitual coffee drinkers before and after consuming coffee or caffeine.
They found that both coffee and caffeine caused changes in brain activity, decreasing “the connectivity of the default mode network.”
According to a press release, this suggests that consuming either caffeine or coffee helped people transition from resting to working on tasks.
However, researchers also found that other modes of activity are exclusively increased among coffee drinkers.
This may be due to the sensory experience of drinking coffee of other compounds present in coffee.
Dr. Antonio Teixeira, professor of psychiatry and director of the Neuropsychiatry Program at UTHealth Houston, not involved in the study, told Medical News Today:
“The authors concluded that part of the common effects attributed to coffee might be related to mechanisms other than caffeine itself. Among these other mechanisms, they mention the whole experience of drinking coffee- that might involve some placebo effect, expectations, and even withdrawal, which were not investigated in the study.”
For the study, the researchers recruited 47 people who drank at least one cup of coffee per day. They were an average of 30 years old, and 31 were women.
All participants were asked to abstain from consuming caffeinated drinks or food for at least three hours before participating in the study.
Once in the lab, the participants underwent two fMRI scans: one before and one 30 minutes after taking caffeine or drinking a cup of coffee. During the fMRI scans, participants were asked to relax and let their minds wander.
Ultimately, the researchers found that both coffee and caffeine reduced functional connectivity, in the default mode network (DMN). The DMN is associated with “self-referential processes when participants are at rest” as noted by the authors.
The researchers noted that decreased DMN indicates higher preparedness to switch from resting to task-context processing.
They further noted that coffee consumption, but not caffeine consumption, significantly decreased connectivity between somatosensory and motor networks of the brain. The researchers wrote that this might explain why people report improved psychomotor efficiency after drinking caffeinated coffee.
Consumption of coffee, but not caffeine, also led to increased activity in executive control and visual networks implicated in visual processing.
Coffee consumption also led to better cognitive function, including improvements in:
- working memory
- cognitive control
- goal-directed behavior
The researchers wrote that the differing effects of taking caffeine and drinking coffee may stem from the sensory experience of drinking coffee.
Armargo Couture, Registered Dietitian Nutritionist at Staten Island University Hospital, New York, not involved in the study, noted that the extra effects of drinking coffee may be explained via the placebo effect:
“The placebo effect might work in this case due to the fact that culturally, drinking a cup of coffee before starting your day is the social norm. Essentially, many associate their “morning coffee” with “waking up” and preparing for the day ahead.”
“After waking up, many people will routinely drink their morning cup of coffee before starting their day, which naturally becomes associated with being productive. Preparing for your day with a morning coffee is a collective experience and the social norm, which is where the coined phrase “don’t talk to me until I’ve had my morning coffee” came from,” she added.
Couture noted, however, that coffee’s extra effects may also arise from other compounds within.
“Components of coffee, such as terpenes — cafestol and kahweol, and polyphenols such as chlorogenic acids, interact with various brain receptors to increase energy, increase mood, and give us that motivated mindset. The terpenes and polyphenols in coffee have been researched and shown to have anti-inflammatory and antioxidant properties which has been associated with a lower risk of depression as well,” she added.
Dr. Teixeira noted that important limitations to the study include a lack of inclusion of non-drinker or decaf-drinker groups and a lack of task-related fMRI data or cognitive assessments.
“The researchers assessed neural connectivity through fMRI, and this is different from actually evaluating cognitive performance. This is a very common misinterpretation in the lay literature,” he noted.
“It is [also] unclear how matched [the coffee and caffeine groups] were regarding sociodemographic and coffee and/or other caffeinated beverage consumption,” he added.
Dr. Gregory S. Carter, PhD, associate professor of neurology and Sleep Medicine Section Chief for the Department of Neurology at the University of Texas (UT) Southwestern Medical Center, not involved in the study, also told MNT:
“The prime limitation is the timeline from the ingestion of coffee or caffeine to the performance of the fMRI. Dissolved caffeine [takes 50-60 minutes to reach maximum concentration in the blood]. The authors tested at 30 minutes, which would be a little early- especially if the relatively quick transit across the blood-brain barrier is added.”
Dr. Michael J. McGrath, board certified psychiatrist and Medical Director at the Ohana Luxury Alcohol Rehab, not involved in the study, also told MNT that the results are further limited as the researchers did not test whether the benefits coffee drinkers experience come from relieving withdrawal symptoms.
“Drinking coffee increased subjects’ executive control which means coffee may benefit your mindset towards goals while improving your working memory and cognition,” Couture said.
“For those who have difficulty with executive dysfunction, drinking coffee may benefit you by increasing your motivation and working memory,” she added.
Dr. McGrath also noted that the results show that some of the benefits of drinking coffee come independently from caffeine. This, he noted, means that drinking decaffeinated coffee in the morning may also make people feel more alert and focused.