Decaf Coffee May Improve Memory, Study Finds
- As the public continues to think about dietary changes for the right digestive balance, coffee has the potential to also be harnessed as a further intervention as part...
- Coffee drinkers who switch to decaf may gain unexpected cognitive advantages, as a new study published in April in Nature Communications shows that decaffeinated coffee significantly improves memory...
- In an experiment conducted by APC Microbiome Ireland at University College Cork, 31 habitual coffee drinkers stopped drinking their usual three to five cups daily for two weeks.
As the public continues to think about dietary changes for the right digestive balance, coffee has the potential to also be harnessed as a further intervention as part of a healthy balanced diet.
John Cryan
Coffee drinkers who switch to decaf may gain unexpected cognitive advantages, as a new study published in April in Nature Communications shows that decaffeinated coffee significantly improves memory and reduces emotional reactivity.
Memory Improvements Seen Only in Decaf Drinkers
In an experiment conducted by APC Microbiome Ireland at University College Cork, 31 habitual coffee drinkers stopped drinking their usual three to five cups daily for two weeks. After this withdrawal period, half the participants received decaffeinated coffee and the other half received caffeinated coffee for three weeks without knowing which version they were consuming. Only the participants who drank decaffeinated coffee showed significant improvements on two memory tests involving learning words and remembering locations. Meanwhile, the group drinking caffeinated coffee showed no significant improvements on those specific memory tests.
Gut Microbiome Shifts Linked to Mood and Stress
Reintroducing coffee triggered acute microbiome changes regardless of whether caffeine was present. Both caffeinated and decaf coffee drinkers reported lower perceived stress, depression, and impulsivity after resuming coffee consumption. However, the two versions of the beverage produced distinct physiological benefits. Caffeinated coffee reduced anxiety and improved attention and vigilance, while decaffeinated coffee improved sleep quality and physical activity. Stress neurobiologist John Cryan explained that coffee interacts with gut microbes through complex plant compounds rather than caffeine alone.
Polyphenols and Microbial Interactions Under Investigation
Although caffeine crosses the blood-brain barrier directly, coffee contains more than a thousand other compounds, including numerous polyphenols that feed human gut microbes. The study found that coffee consumption increased Firmicutes bacteria, which are associated with positive emotions in women, along with bacteria tied to intestinal gastric acid secretion and bile acid synthesis. Coffee’s non-caffeine compounds are processed by gut bacteria into metabolites that may influence biological pathways involved in inflammation, mood, and brain function. Researchers emphasize that these findings rely on a small group of healthy adults and do not prove that coffee can prevent depression or replace professional mental health care.