Growing Older Without (Too Much) Rust

If you had to pick just one, this would probably be it. Physical exercise is one of the factors with the strongest scientific backing when it comes to brain health and ageing.

Muscle isn't simply something useful for climbing stairs or opening particularly stubborn jars. When it contracts, it releases substances that take part in communication with other organs, including the brain. Exercise has been linked to beneficial changes in the hippocampus, a structure fundamental to memory and especially vulnerable to ageing and to conditions like Alzheimer's.

That's why it makes sense to combine aerobic activity and strength training, alongside something much simpler: not spending half your life sitting down.

The brain doesn't live in isolation inside the skull. The gut maintains constant communication with it through nervous, hormonal, and immune pathways; among them, the vagus nerve.

The composition of our gut microbiota appears to influence multiple aspects of health, though it's worth being cautious, since it's still a young field of research and rather prone to spectacular headlines. What we do know with much more certainty is that a varied diet, rich in minimally processed foods, fibre, vegetables, legumes, fruit, and other plant-based foods, favours a more diverse microbiota than a diet based on ultra-processed food.

No need to buy a yoghurt promising to "activate your neurons." Eating reasonably well remains less thrilling, but considerably more sensible.

For years we've boasted about sleeping little, as if tiredness were proof of productivity. The brain, unfortunately, doesn't seem impressed.

Good sleep takes part in essential processes related to memory, learning, emotional regulation, and the clearance of certain metabolic byproducts. And what matters here isn't just quantity, but a degree of regularity too: fairly stable hours, less stimulation before bed, and conditions that let the nervous system gradually wind down.

Nighttime rumination deserves a mention of its own. We all know that remarkable talent the brain has for waiting until two in the morning to remind us of something awkward we said back in 2007.

Meditation is one of the areas Castellanos has studied with particular interest. There's research linking regular practice to changes in brain regions involved in attention, emotional regulation, body perception, and memory.

That doesn't mean twenty minutes of meditation turns the brain into an eternally young organ. The studies are complex, methodologies vary, and it's difficult to separate the effect of meditation from the lifestyle of people who've practised it for years.

But the body of evidence does point to something interesting: deliberately training attention and body awareness seems to have measurable effects on the brain.

And you don't need to build an altar to do it. Sitting down, noticing the breath, and returning to it whenever the mind wanders off on its own already offers plenty of work.

Here, obviously, I'm playing on home turf.

Yoga combines elements we already know, individually, can be beneficial: movement, strength, mobility, balance, attention, body perception, and breath regulation. Some research has found associations between these practices and favourable changes in certain brain structures and functions.

Breathing turns out to be especially interesting because it occupies a peculiar position: it works automatically, but we can also change it consciously. By changing its pace we influence signals reaching the brain and the activity of the autonomic nervous system.

No need to turn every inhale into a mystical experience. Breathing a little slower and paying attention to what we're doing is already quite a lot. If you'd like to practise it, you'll find several guided patterns on the Breathe page.

Posture isn't just a matter of the spine. The brain constantly receives information about the position of the body and uses those signals to build our perception of our internal state.

Some studies suggest that certain body positions can influence variables like mood, attention, or the tendency to ruminate. That doesn't mean "sitting up straight cures depression" (unfortunately, the human body doesn't run on slogans), but it does mean that posture, breath, emotion, and attention form a much more interconnected system than we tend to imagine.

Perhaps it's another good reason to change position now and then, and to remember we have a body below the neck.

Walking, dancing, playing a sport, or any activity that demands coordination sets very broad brain networks in motion. When we also do it with other people, another important factor in healthy ageing comes into play: social connection.

Dancing is particularly interesting because it blends physical activity, memory, rhythm, coordination, attention, and interaction with others. Some studies even suggest physiological synchronisation when several people share movements or rhythms.

So going out dancing was probably healthier than we thought. Even if the music was questionable.

Learning something new tends to get slower with age. That doesn't mean the brain has stopped learning.

Languages, music, reading, games, manual skills, studying, travel, conversation, computing, gardening: any activity that pushes us out of automatic responses can help keep certain cognitive networks active.

One idea matters to me here: it's not about doing crosswords because someone told us they're good for the brain, but about staying interested in things.

Curiosity may be one of the most pleasant forms of resistance to ageing: still having things we don't understand, and the will to understand them.

We live surrounded by stimuli and have picked up the habit of immediately filling any gap. If thirty free seconds appear, out comes the phone. If we're waiting for a lift, same thing. If the lift takes twelve seconds, we start to suspect we're wasting our lives.

Castellanos stresses the value of introducing small conscious pauses throughout the day. Closing your eyes, putting the screen down, feeling the body, or paying attention to a few breaths can help interrupt that constant build-up of stimulation.

No need to call it meditation. You can just call it standing still for two minutes doing nothing.

And maybe that's exactly why it's so hard.