Caffeine Slows Down Development in Teenage Brains: Coffee Impacts Maturation

There's some bad news for any teenage coffee drinkers out there. It turns out that caffeine can slow down brain development in pubescent brains. The findings reveal the importance of understanding exactly how caffeine can impact young brains.

Caffeine consumption is only going up in both young adults and children. In fact, consumption has increased by 70 percent over the past 30 years. Energy drinks in particular are to blame, but there are also students that turn to coffee for a pick-me-up during late-night cram sessions. That's why it's more important than ever to study exactly what caffeine does to a developing brain.

In order to examine caffeine's effect on the brain a bit more closely, the researchers conducted a study on rats. Both in humans and in rats the duration and intensity of deep sleep as well as the number of synapses or connections in the brain increase during childhood. These connections reach their highest level during puberty before dropping again once the individual matures into an adult.

"The brain of children is extremely plastic due to the many connections," said Reto Huber, one of the researchers, in a news release. "This optimization presumably occurs during deep sleep. Key synapses extend, other are reduced; this makes the network more efficient and the brain more powerful."

The researchers gave moderate quantities of caffeine to 30-day-old rats over five days. They then measured the electrical current generated by their brains. Surprisingly, they found that the deep sleep periods, which are characterized by slow waves, were reduced from day 31 until day 42. That was well beyond the end of administering caffeine. Compared to the rats given pure drinking water, the caffeinated rats had far more neural connections. In other words, the caffeine was slowing the maturing process in the brain.

That's not all the scientists found, though. The caffeine also impacted the rats' behavior. While rats normally become more curious with age, the rats given the caffeine remained timid and cautious. This seemed to indicate that, in fact, caffeine has a large impact when it comes to the maturation process.

While the study was conducted on rats, it could also have implications for humans. The amount of caffeine that children and adolescents consume keeps rising. As it does, it's more important than ever to understand how caffeine could impact development and growth.

The findings are published in the journal PLOS One.