We are living longer than ever. Life expectancy keeps rising and, with it, a question that concerns more and more people: how can we keep our brain healthy as we age?
For decades it was assumed that cognitive decline was an inevitable consequence of time. Forgetting names, losing mental agility or having a reduced ability to learn seemed like a natural part of ageing. However, scientific research in recent years is profoundly changing this view.
Today we know that ageing does not necessarily mean deterioration. And, above all, we know that much of brain health is built long before the first symptoms of any disease appear.
This was one of the central messages of the round table Keep Your Brain Young: Certainties and Strategies for a Healthy Mind, held at CosmoCaixa Barcelona as part of the LongevitIA congress, organised by Grupo Godó. Neurologists Pablo Villoslada and Mercè Boada, together with microbiologist Alex Mira, took part—three leading experts who approached brain ageing from complementary perspectives but reached a common conclusion: our brain’s health depends far more on what we do every day than previously thought.
The brain does not age alone
One of the major paradigm shifts in current science is the understanding that the brain does not work in isolation. It maintains constant communication with the immune system, metabolism, hormones and even the trillions of microorganisms that inhabit our body.
For Alex Mira, one of the most surprising discoveries of recent years is realising how strongly the microorganisms in our body can influence brain function. Research on the microbiome has shown that certain bacteria play a role in regulating inflammation, stress responses and even processes related to mental health.
And the focus is no longer limited to the gut. Oral microbiota is also beginning to reveal a much greater influence than previously thought. There is growing evidence linking specific alterations in oral bacteria to inflammatory processes that may affect brain ageing.
Experiments in animal models even show that microbiota can modify stress responses. The brain can no longer be understood as an isolated organ, but rather as part of a complex biological network involving the gut, the mouth, the immune system and the rest of the body.
This new perspective requires broadening the concept of brain health. Taking care of the brain is no longer just about doing crosswords or keeping the mind busy. It also means sleeping well, eating properly, maintaining high‑quality social relationships and preserving the balance of the microbial ecosystems that live with us.
Genetics is only the starting point
Another certainty that science is beginning to consolidate is that genes do not fully write our story.
Pablo Villoslada reminded the audience that genetics is an important part of the equation, but not the whole story. Some genetic variants, such as APOE4, increase the risk of developing Alzheimer’s disease, especially when two copies of the gene are inherited. However, he stressed that knowing about a genetic predisposition should not be interpreted as a sentence.
On the contrary. Healthy lifestyle habits can offset part of that risk, and in the near future will allow even more personalised preventive strategies and treatments.
As Villoslada summarised with a memorable image, genes carry part of the backpack, but they do not determine the entire path.
There is increasing evidence that regular physical activity, restorative sleep, intellectual stimulation, a balanced diet and controlling factors such as hypertension, diabetes or obesity help build greater cognitive reserve and protect the brain from the effects of time.
The good news is that it is never too late to start. Although the benefits are greater when healthy habits are adopted early, the brain retains its capacity for adaptation and learning throughout life.
Not all forgetfulness is disease
One of the most significant advances is happening in early detection.
Until a few years ago, many neurodegenerative diseases could only be diagnosed when symptoms were already evident. Today, the situation is beginning to change thanks to the development of biomarkers capable of identifying brain alterations decades before the first clinical signs appear.
But Mercè Boada wanted to send a reassuring message first.
Occasionally forgetting a name, a word or where we left our keys does not necessarily mean we are developing a neurodegenerative disease. Normal ageing and cognitive decline are different processes.
The key is not an isolated lapse, but how these changes affect autonomy, orientation, problem‑solving ability or daily functioning.
This distinction is essential. The growing availability of biomarkers and early‑detection tools offers an extraordinary opportunity to shift from reactive medicine to anticipatory medicine. But it also requires careful communication with the public.
Knowing your risk does not mean living in fear. It means having more information to make decisions, adopt protective habits and plan strategies that help preserve autonomy and quality of life for longer.
Making decisions that help your brain stay young
Many of the tools we now know support brain health are within reach of almost everyone. Exercising regularly, sleeping well, following a healthy diet, taking care of oral health, controlling cardiovascular risk factors, maintaining an active social life and continuing to learn throughout life are habits that science associates with healthier brain ageing. None of them guarantees absolute protection, but together they form the best strategy we currently know to preserve brain health.
A new paradigm for long‑lived societies
Perhaps the greatest lesson from current research is that we must stop thinking about the brain only in terms of disease.
Brain longevity is not just about avoiding cognitive decline. It is about preserving what allows us to remain ourselves: memory, the ability to learn, to feel emotions, to connect with others and to build new projects.
The great lesson science offers is that the brain is not cared for only when problems arise. It is built day by day, long before that. Every walk, every conversation, every night of sleep and every new learning experience is a small investment in a more resilient mind.
In a society that aims to live increasingly longer lives, keeping the mind young is no longer a matter of luck. It is, more and more, an opportunity supported by scientific evidence.
