Brain Health at 70+: What You Can Still Change Today

You walk into the kitchen and stop. You came in here for something — you knew you did — and now there’s a blank where the reason used to be. Hand on the counter, waiting for it to come back.

For a lot of readers, that small blank comes with a second thought right behind it, colder than the first: Is this how it starts?

I want to begin right there, in that half-second, because it’s the real reason brain health is so hard to read about. It isn’t a neutral topic. Under every article about “cognitive decline” is a fear most people carry and rarely say out loud — that the mind is the one thing you can’t afford to lose, and that losing it might already be underway, quietly, without your permission.

That fear isn’t silly, and I’m not going to talk you out of it with brightness. Forgetting a word, losing a name, walking into a room empty-handed — these do happen more with age. It makes complete sense that they scare you.

But when you actually read the research — not the headlines, the research — it says something the fear never mentions. A surprising amount of what shapes your brain’s future is still in your hands. Even at seventy, or seventy-five.

This week is a good excuse to tell you about it: July 22nd is World Brain Day. This year’s campaign is about brain health for everyone — and one of its plainest messages is that prevention starts in everyday life. Which is exactly where this article goes.

The number that changed how I think about this

In 2024, the Lancet Commission — a group of the world’s leading dementia researchers — published an update I keep coming back to. Their conclusion: up to 45% of dementia cases could, in theory, be prevented or delayed by addressing fourteen risk factors across a person’s life.

Sit with that fraction for a second. Nearly half — tied to things that aren’t written in stone.

The word that matters in that sentence is modifiable. It means changeable.

The part that’s still on the table

The Commission sorts those fourteen factors by life stage — some matter most in school years, some in midlife. But a whole cluster sits in what they call later life: the ones still open in your sixties, seventies, and beyond. Physical inactivity. Social isolation. Depression. Diabetes. Smoking. Air pollution. And, newly added in 2024, untreated vision loss.

Look at that list again. Almost none of it is exotic. No gene therapy, no expensive scan, nothing you’d fly to a clinic for. It’s how much you move. Who you stay connected to. Whether you get your eyes and ears checked. Whether a low mood gets treated instead of endured.

Ordinary, unglamorous, and still within reach at seventy. Here’s what the evidence actually says about a few of them, because the specifics are more encouraging than “stay sharp” ever is.

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Four levers, and what the research says about each

Your hearing. This one surprised me most. Untreated hearing loss is one of the single largest modifiable risk factors on the whole list — the leading theory is that a brain straining to hear has less left over for memory and thinking, and slowly withdraws from the conversations that keep it engaged. In a large trial called ACHIEVE, older adults were given hearing aids and support. The honest version: across everyone, the result was modest. But among those already at higher risk, treating their hearing slowed cognitive decline by nearly half over three years. If you’ve been putting off that hearing test, this is your reason. (I wrote a whole article on how quietly hearing slips, and why it’s so easy to ignore: The Sound You Stop Noticing You’re Missing.)

Your movement. Not the gym. Just motion, regularly. A review pooling dozens of long-term studies found that people who were more physically active had roughly a 35% lower risk of cognitive decline over the years they were followed. Walking counts. Gardening counts. The stairs count. Your brain doesn’t know the difference between a treadmill and a walk to the shops — only whether you moved.

Your blood pressure. Quietly powerful, because it runs in the background while you feel nothing. In a major trial called SPRINT MIND, older adults who brought their blood pressure down more tightly had about 19% fewer new cases of mild cognitive impairment — the stage that often comes before dementia. A number on a cuff, managed with your doctor, turns out to be brain care too.

Your mind and your people, kept in use. This is the finding I’d tape to the fridge, because it answers the exact fear at the top of this letter. Researchers followed more than ten thousand older adults — all of them past seventy, not midlife — for ten years. Those who kept reading, writing, taking classes, and playing games had a meaningfully lower risk of dementia: around 11% lower for the reading and writing, 9% lower for the games and puzzles. Not started at forty. Started in their seventies. And it still moved the needle.

What this doesn’t mean

I want to be careful here, because the space between “you have real influence” and “it’s all your fault” is exactly where this kind of advice goes wrong.

None of this is a guarantee. Plenty of people do everything on this list and develop dementia anyway, through no failure of their own — and if that’s your family’s story, I’m not standing here implying someone didn’t try hard enough. Some of the risk is genes and age and plain bad luck, and it deserves to be named as such, not quietly blamed on the person carrying it.

So this isn’t a to-do list you can fail. It’s the opposite. After years of being told the brain is a slow, one-way decline you just brace for, a good part of it turns out to still be open.

The smallest possible start

You don’t have to do the whole list. You shouldn’t try — nothing kills a good habit faster than starting all fourteen at once.

Pick one. The one you already knew, reading this, was yours. The hearing test you keep rescheduling. The walk you used to take and quietly dropped. The friend you’ve been meaning to call back. The blood pressure you haven’t checked since your last appointment.

Choosing one and starting is the entire mechanism these studies are describing, shrunk down to something you can do this week.

The fear in the kitchen told you the story was already over, decided somewhere you couldn’t reach. The research says something better, and it happens to be true: a large part of it is still close enough to touch. Not all of it — but more than fear admits.

You walked into the kitchen for a reason. Some of the best ones are still yours to choose.

If you want the fuller picture, I’ve written the companion pieces: what we actually now know about preventing dementia, and whether a daily puzzle really does anything for your brain.

## Why this one gets a whole month

A single article isn't enough for a subject this size. It matters too much, and there's too much worth saying properly — so I'm giving it all of August. Every Sunday next month, the paid edition takes one piece of this and slows right down with it: what actually keeps a mind engaged and what quietly dulls it, how to start learning something new when it's been years, the kinds of learning that give you the most back at this stage of life, the small daily habits that clear the mental fog, and how to build a life that simply keeps you curious.

If you'd rather not miss any of it, this is the moment. Becoming a Plus member means every Sunday of August lands in your inbox — you can read more about it here 👇