Caffeine linked to shorter sleep and brain changes in late childhood

A study of more than 9,600 children aged nine to 11 found that higher caffeine intake was associated with shorter sleep, differences in brain structure and more attention, mood and behavioural symptoms.

Researchers have found that caffeine intake in late childhood is linked with shorter sleep, changes in brain structure and more mental health symptoms, according to a new study highlighted by Mehr News and published in a peer-reviewed journal. The work adds to growing concern that what children drink in the school day may matter not only for rest, but also for brain development and emotional wellbeing.

The study examined 9,632 children aged nine to 11 and tracked how much caffeine they consumed, how long they slept and what their MRI scans showed. Most of the caffeine came from soft drinks, with coffee and tea also contributing. According to the researchers, higher caffeine intake was associated with a smaller cortical surface area and reduced cortical thickness, both measures of the brain’s outer layer, which is involved in attention, decision-making and emotion.

Sleep appeared to play a key role. The researchers found that children who consumed more caffeine tended to sleep for less time, and that shorter sleep partly explained the link between caffeine and poorer mental health outcomes. The children with the highest caffeine intake also reported more problems with attention, mood and behaviour.

Divyangana Raksh, the lead author from King’s College London, said in comments carried by Mehr News that caffeine has become such a routine part of daily life that adults can overlook how often young people consume it. She said the findings suggest that both caffeine intake, including from fizzy drinks, and sleep deserve attention when adults think about children’s mental health. The study’s authors argued that clearer guidance on caffeine use in adolescence may be needed to support healthy brain development.