Humans and other mammals show particularly intensive sleeping patterns during puberty – this is also the period during which the brain matures the most; but when pubescent lab rats were administered coffee, their brains matured much slower and not so efficient, a new study shows; considering that children’s and young adults’ coffee consumption has increased dramatically in the past decades, by 70% in the past 30 years, this is a serious matter of concern.

There are many reasons to worry about the increased consumption in teenagers and young adults (which if trends continue, will grow even more). Researchers led by Reto Huber of the University Children’s Hospital Zurich are now adding new arguments to the debate: their research on rats showed that the equivalent of three to four cups of coffee per day in humans results in reduced deep sleep and (perhaps consequently) a significantly delayed brain development.

“The brain of children is extremely plastic due to the many connections,” says Huber. When the brain then begins to mature during puberty, a large number of these connections are lost. “This optimisation presumably occurs during deep sleep. Key synapses extend, others are reduced; this makes the network more efficient and the brain more powerful,” says Huber.

Both in humans and in rats, the number of synapses grows dramatically during childhood and puberty, which makes it highly plausible that the results obtained in rats are coherent with what you would see in humans. Even if the rat brain differs significantly from the human brain, there are certainly some resemblances, and probably, some similar reactions to the pick-me-up.

Another interesting efect was that the slower maturing process of the brain was also associated with behavioral traits: instead of becoming more curious and active, rats on caffeine were much more timid and shy.

Journal Reference.

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