While adolescents are fast asleep, their brains are busy maturing, making key connections (synapses), a process that continues until adulthood. But the amount of caffeine kids consume may be disrupting that process, warn a group of Swiss researchers who investigated how caffeine acts on the brains of rats. A study from the team at the University Children’s Hospital Zurich shows that caffeine intake equivalent to three or four cups of coffee per day reduced rats’ deep sleep and delayed the animals’ brain development. The researchers gave 30-day-old rats moderate amounts of caffeine over five days and measured the electrical current generated by their brains. They found that deep sleep periods were reduced from day 31 until day 42, seven days beyond the time the rats received the caffeine. Not only did the rats’ brain maturation slow, but the investigators reported that the animals, which normally grow more curious with age, remained timid and cautious. The researchers suggested that even if rat brains differ clearly from the human brain, there are enough developmental parallels to raise the issue of whether caffeine intake during puberty is harmless. The study was published in PLoS ONE on September 4, 2013.
Nadja Olini, Salomé Kurth, and Reto Huber. “The Effects of Caffeine on Sleep and Maturational Markers in the Rat,” PLoS ONE, September 4, 2013; DOI: 10.1371/journal.pone.0072539