The brain matures rapidly during puberty and pre-puberty as cortical connectivity advances but the researchers led by Reto Huber of the University Children’s Hospital in Zurich, Switzerland, found the equivalent of 3-4 coffees per day in humans provoked brain maturity to slow as measured by, “electrophysiological recordings, behavioral and structural readouts”.
Reduced deep sleep was also observed, with Huber suggesting the two phenomenon are interlinked.
Slow brain wave activity and sleep
“The brain of children is extremely plastic due to the many connections,” said Huber. “This optimisation presumably occurs during deep sleep. Key synapses extend, others are reduced; this makes the network more efficient and the brain more powerful.”
The study fed the varying caffeine doses to 30-day-old rats for five days and measured slow brain wave activity (SWA) which they noted was affected until day 42.
The researchers found the caffeinated rats which normally become more curious with age, were timid and cautious compared to the placebo group on water.
“No matter what mechanism applies our study shows that caffeine interferes with cortical maturation during a critical developmental period,” they wrote.
“This might also be of clinical importance since the critical period of synapse elimination during adolescence is associated with an increasing incidence of psychiatric and mood disorders, such as schizophrenia, anxiety, substance abuse and personality disorders.”
“Thus, it will be important for future studies to investigate the effects of chronic caffeine application during critical periods of development in animal models for psychiatric and mood disorders.”
‘The Effects of Caffeine on Sleep and Maturational Markers in the Rat’
Authors: Olini N, Kurth S, Huber R