A new study reveals that abstaining from coffee for just two weeks can lead to reduced impulsivity and stress levels. Switching to decaf may also improve sleep and memory, suggesting benefits beyond caffeine.

Study Details & Methodology

Researchers at University College Cork in Ireland conducted a study published in Nature Communications. The research tracked 62 healthy adults – 31 regular coffee drinkers and 31 non-coffee drinkers – over several weeks.

The study involved collecting baseline data through blood, urine, stool samples, and questionnaires. Participants then abstained from coffee for two weeks, during which regular coffee drinkers showed a decrease in impulsivity and emotional reactivity.

Effects of Caffeine vs. Decaf

Following the withdrawal period, participants were assigned to either caffeinated or decaffeinated coffee for 21 days. Those who resumed caffeinated coffee reported reduced anxiety and psychological distress.

Conversely, participants consuming decaffeinated coffee experienced improvements in sleep quality, increased physical activity, and enhanced memory performance. This suggests coffee’s benefits extend beyond caffeine’s stimulant effects.

Gut Microbiome Changes

The study also revealed differences in the gut microbiome composition between coffee drinkers and non-drinkers. Regular coffee drinkers displayed a distinct microbial profile that shifted during the two-week withdrawal.

Both caffeinated and decaffeinated coffee triggered further alterations in the gut microbiome, suggesting compounds like phenolic acids may play a role.

Inflammation & Coffee

Regular coffee drinkers initially had lower levels of C-reactive protein (inflammation marker) and higher levels of IL-10 (anti-inflammatory molecule). These levels shifted during withdrawal.

Reintroducing both caffeinated and decaffeinated coffee was associated with a reduced inflammatory response in laboratory tests.

Study Limitations & Future Research

Researchers emphasize the study doesn’t prove a direct causal link between coffee and improved health. The small sample size (62 participants) and limited diversity require further investigation.

Some memory improvements may be due to practice effects from repeated testing. Larger, more diverse studies are needed to validate these findings and assess long-term health benefits.