Your daily coffee habit may affect your brain and mood in unexpected ways, study finds

Key Points:

• A University College Cork study found that both caffeinated and decaffeinated coffee are linked to changes in gut microbes and mood, with each type affecting cognition differently.
• After reintroducing coffee, participants reported reduced stress, depression, and impulsivity; caffeinated coffee drinkers also showed decreased anxiety and improved attention, while decaf drinkers improved episodic memory.
• The study observed changes in gut bacteria among coffee drinkers but could not establish a direct causal link between these microbial changes and mood or cognitive effects.
• Experts caution that the small sample size and potential confounding factors limit the ability to generalize findings, and improvements in cognitive tests may not reflect real-world benefits.
• Researchers emphasize that changes in self-reported mood should not be interpreted as coffee treating clinical depression, and further research is needed to clarify coffee’s effects on the gut-brain axis.