Caffeine causes a degradation of gray matter and blocks the brain's ability to recover after a lack of sleep; therefore, be cautious with its consumption when you are sleep-deprived.

noli's read

The claim blends real neuroscientific observations with a preventive interpretation. Studies (e.g., Cerebral Cortex, 2021) show that regular caffeine consumption does indeed induce temporary variations in gray matter volume, although these changes appear reversible after a period of abstinence. Regarding sleep, it is well established by randomized controlled trials that caffeine disrupts the structure of recovery sleep (less deep sleep, increased fragmentation). However, the idea that caffeine totally blocks recovery is nuanced by recent work showing that it can, in certain specific circuits (hippocampus), help restore cognitive functions impaired by sleep deprivation. The term 'degradation' is therefore a fairly strong simplification of complex and often temporary cerebral plasticity. The direct causal link between caffeine, permanent structural degradation, and total failure of recovery is not as clear-cut as the post suggests.

the sources

No named source held this one up — that absence is part of the verdict.