Dementia, that dreaded disease that steals memories, identities, and lives, usually appears in old age. But a recent scientific analysis has given an alarming twist to our understanding of the problem: the roots of cognitive decline could lie much further back, in childhood .

The study gathered data from several countries and found that children with obesity, sedentary habits, and poor diets were more likely to face cognitive problems decades later. This is because brain health is a cumulative process: arteries, inflammation, and brain plasticity begin to form (or deteriorate) from early stages.

For example, childhood obesity is linked to insulin resistance, hypertension, and microinflammation, which, over time, affects blood flow to the brain . A sedentary lifestyle, meanwhile, limits the development of neural connections, reduces the release of substances like dopamine and serotonin, and diminishes the brain's ability to adapt and learn.

What's most alarming is that these effects are silent. A sedentary child may have acceptable academic performance, but is developing a less resilient, less flexible brain that is more vulnerable to neurodegenerative diseases.

The good news is that prevention is possible . Promoting physical play, limiting screen time, and offering foods rich in omega-3 fatty acids, antioxidants, and healthy proteins are strategies that, although they may seem simple, could be key to healthy brain aging.

💡 The message is clear: it's not enough to think of dementia as just an issue for older adults. If we want long-lived societies, we need to start taking care of brains from the moment children take their first steps.