What Happens To The Brain When You Drink Decaffeinated Coffee?
- 8.10.2026, 8:55
Scientists believe that gut microorganisms may play a certain role.
Decaffeinated coffee may be less effective than regular coffee in terms of its energizing effect, but it may potentially benefit memory. In an experiment, participants who drank decaffeinated coffee performed significantly better on two memory tasks, while those who consumed caffeinated coffee showed no improvement, according to "Cursor".
The study, published in *Nature Communications*, suggests that coffee’s effect on the brain may not be due solely to caffeine. Scientists speculate that gut microbes may play a role.
“Coffee is more than just caffeine: it’s a component of our diet that interacts with our gut microbiota, metabolism, and even our emotional well-being. Our results suggest that coffee—with or without caffeine—can influence health in different but complementary ways,” — emphasized John Kryan of University College Cork in Ireland.
In 2013, Cryan and his colleague Ted Deenan coined the term “psychobiotics” to describe the potential influence of probiotics on the gut microbiome and mental health through their interaction with the brain.
Now, Kryan is studying the link between coffee and the “gut-brain axis.” The scientist suggests that some of the effects of morning coffee may be linked not so much to caffeine as to the beverage’s impact on gut microorganisms. He is paying particular attention to polyphenols—plant compounds found in coffee that are thought to influence the microbiome.
The study involved 31 participants who temporarily gave up coffee. After reintroducing coffee into their diets, the participants’ gut microbiome changed noticeably, and this effect was observed even with decaffeinated coffee. Perceived stress, depression, and impulsivity also decreased.
However, only caffeinated coffee was associated with reduced anxiety and psychological distress, as well as increased attention and alertness.
The results confirm caffeine’s potential specific influence on mood and cognitive function; however, Krayan noted that changes were also observed after consuming decaffeinated coffee. Specifically, this group showed improved performance on two memory tests.
The researchers suggest that the effect may be linked to polyphenols, which affect gut microbiota and, via the gut-brain axis, influence cognitive function.