Plate Nº 61 · recorded November 12, 2026
Neuroscience & MindReported finding
Caffeine Tied to Shorter Sleep and Brain Differences in Kids as Young as Nine
A study of 9,632 U.S. children aged nine to 11 links higher caffeine intake — mostly from soft drinks — to shorter sleep and slightly smaller cortex surface area across 22 brain regions.
By Elena Vasquez3 min read565 words
In brief
- Researchers analyzed data from 9,632 children aged nine to 11 in a long-running U.S. brain development study.
- Higher caffeine intake was linked to slightly smaller cortex surface area in 22 regions across all four major cortical sections.
- A difference appeared even among children reporting about one caffeinated drink a week versus none.
- Soft drinks were the children's main source of caffeine.
- The study was published in Biological Psychiatry: Cognitive Neuroscience and Neuroimaging.
Children as young as nine who drink more caffeine sleep less and show small differences in the shape of the brain's outer layer. That's the headline finding from a large U.S. study of nine- to 11-year-olds, and their main caffeine source wasn't coffee. It was soft drinks.
The research, led by King's College London and published in Biological Psychiatry: Cognitive Neuroscience and Neuroimaging, analyzed data from 9,632 children enrolled in a long-running study of brain development. Each child reported how often they drank caffeinated soft drinks, coffee or tea in a typical week.
The stakes are real. Sleep matters enormously at this age, when children are learning to manage emotions, focus attention and keep up with growing demands at school. The study gives researchers a concrete reason to look more closely at caffeine alongside the other factors that shape how much rest children get.
What did the brain scans show?
The team used MRI scans to examine the cortex — the folded outer layer of the brain. They measured its thickness and how much surface area it covered, then matched those measurements against the children's reported caffeine intake.
Higher intake was linked to slightly smaller surface area across parts of the cortex. The pattern showed up in 22 regions spread across all four major sections of the cortex. It persisted even after the researchers accounted for differences in family income and parental education.
Soft drinks drove much of the association. The researchers saw a difference in overall surface area even among children reporting roughly one caffeinated drink a week, compared with children reporting none.
That's a remarkably low threshold. One drink a week.
Does caffeine cause the brain differences?
Not proven. A difference between groups does not show what caused it, and the researchers are careful on this point.
The team also examined reports of the children's mental health six and 18 months later. Their analysis suggested shorter sleep may be part of the relationship linking caffeine, the brain measures and later mental health symptoms.
Several other explanations remain on the table:
- A child who drinks caffeinated soda may also consume more sugar
- That child may simply have different daily routines
- Children who already sleep poorly may be more likely to reach for a drink that makes them feel alert
In other words, the caffeine could be a marker for a broader lifestyle pattern rather than the culprit itself.
What are the study's limits?
Plenty, and the authors flag them. The study relied on children's reports of drinks rather than measuring every milligram of caffeine. A small can and a large bottle can contain very different amounts. Timing matters too — an afternoon cola may affect sleep far more than a morning one, potentially as much as the weekly count.
The brain differences were also small. They cannot predict how any individual child will develop.
Future research could measure the amount and timing of caffeine more precisely, and test whether changing drink habits actually changes sleep. That would help separate the effect of caffeine itself from the routines and other ingredients that usually come along with it.
The takeaway: more caffeine tracked with less sleep and subtle cortical differences in nearly 10,000 children, but the cause remains an open question — and even one caffeinated drink a week stood out in the data.
via knowridge.com (Source)
More from Elena Vasquez
Show full bio
Correspondent covering money, funding and market shifts around general science news at SciBeat.
384 articles
Nearby plates
- Two to Three Cups of Coffee a Day Linked to Lowest Mood Disorder Rates
- Autistic Brains Process Faces Differently — and Earlier Than Thought
- Childhood abuse linked to brain structure changes in largest neuroimaging study
- Coffee May Lower Diabetes Risk While Caffeine Raises Blood Sugar
- REM Sleep Paradox: Brain's Energy Drops Despite Higher Fuel Supply