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December 16, 2025
Nils Behrens
Health expert Nils Behrens on news from brain research: New data shows five phases of brain age. And each phase determines how long we stay mentally young.
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When talking about the age of the brain, many think of Sudoku, Omega 3, and the question of whether they remember their own door code. But a new analysis from the University of Cambridge shows: The brain follows its very own master plan – divided into five remarkably precise stages of life.
And believe me: These insights are more relevant to longevity than any superfood bowl ever discussed at Healthwise.
In this phase, there is as much activity in your head as in a large kitchen at lunchtime. Synapses are built and torn down as if they were rental contracts in Berlin.
This is the time when it is decided how stable the basic architecture will be – the foundation for everything that comes later: concentration, learning ability, stress resilience.
Those who have poor starting conditions here can compensate for a lot later – but not everything. Early childhood nutrients, sleep, and emotional security are practically the first healthspan investments in life.
Welcome to the era where the brain learns as quickly as you discover new biohacks at Healthwise. Neural efficiency climbs steeply.
Between 20 and 30, the brain reaches its peak – processing speed, problem-solving, creativity: everything at its maximum.
Those who sleep like a zombie, eat like an algorithm, and stress like a startup founder during this phase will face the consequences later.
Cognitive reserves are now being built – or burned.
Now the brain works not like a sports car, but like a Swiss watch. Stable, reliable, efficient – just not with turbo anymore. This phase is long. And that's precisely why it is crucial.
Here decides your cognitive future.
Movement, nutrition, sleep, micronutrients, mental hygiene – everything has a long-term effect on neural networks.
This is the era in which the longevity homework must be done.
Nils Behrens, Chief Brand Officer of Sunday Natural and host of the podcast HEALTHWISE
The networks lose speed. Multitasking becomes a duel discipline. And memories no longer always run in full HD.
But: The descent is not inevitably steep.
Who now has solid vascular health, exercises regularly, sleeps well, and keeps inflammation low, can significantly slow down the pace of cognitive decline.
From here, the brain becomes more selective. The networks retract, communication slows down, but often becomes clearer.
Many 90-year-olds develop impressive mental sharpness – not in spite of this phase, but because of decades of nurturing their mindset.
Cognitive preservation at this age is no accident. It is the result of a lifestyle that takes the brain as seriously as the heart and muscles.
The new mapping shows four biographical turning points: around 9, 32, 66, and 83 years. This is the first time we know when lifestyle interventions are particularly effective – and when they fizzle out.
There is no moment in life when the brain is not malleable. But there are moments when it's much easier than others.
In the Healthwise Podcast, I regularly talk about this with scientists and doctors. Because in the end, it's not about thinking as long as possible – but as clearly as possible.
Nils Behrens is the Chief Brand Officer of Sunday Natural and host of the HEALTHWISE podcast. He also teaches as a lecturer at the Fresenius University of Applied Sciences, as a sought-after health expert. Previously, Behrens worked for over 12 years as the Chief Marketing Officer of the Lanserhof Group and host of the successful "Forever Young" podcast.
