Regular Caffeine Consumption Tied to Reduced Brain Volume

Regular caffeine consumption is tied to reduced gray matter volume but not because of its potential negative impact on sleep, new research shows.

Investigators found the impact of caffeine on gray matter appears to be temporary, with a rebound after a period of caffeine abstinence.

So far we don't have clear evidence yet indicating any functional consequences of the reduced gray matter. We also don't know if such restorable plasticity per se entails gains or harms.

The study was published online February 15 in the journal Cerebral Cortex.

To understand whether regular caffeine consumption affects brain structure because of poor sleep, the researchers studied 20 young, healthy, habitual caffeine consumers.

During the double-blind, randomized, crossover study, participants received caffeine (150 mg three times daily) or placebo capsules to take over two 10-day periods and were asked to abstain from caffeine during the study periods.

At the end of each 10-day period, the researchers examined the volume of the participants' gray matter with MRI and sleep quality in a sleep laboratory.

Results showed no difference in participants' depth of sleep, regardless of whether they had taken caffeine or placebo tablets. However, there was a significant difference in gray matter volume between the caffeine and placebo periods.

After 10 days of caffeine, there was a significant reduction in gray matter volume vs placebo. The difference was most evident in the right medial temporal lobe, including the hippocampus, which is essential to memory consolidation.

However, after 10 days of caffeine abstinence, gray matter volume had significantly rebounded.