Most of us have a fairly clear idea of what “looking after our brain” is supposed to involve.
We might do a crossword. Read. Learn something new. Stay socially connected. Perhaps take up a language or finally work out how to play Wordle without cheating.
But have your cholesterol checked?
Get your hearing tested?
They don’t immediately spring to mind as brain-health strategies.
And yet some of the strongest research we now have on dementia suggests perhaps they should.
The **2024 Lancet Commission on dementia prevention, intervention and care** identified 14 potentially modifiable risk factors for dementia across the lifespan. Together, researchers estimated that addressing these factors could prevent or delay around **45% of dementia cases**.
And sitting right at the top of the list were two surprisingly ordinary conditions: **hearing loss and high LDL cholesterol**.
Each was associated with an estimated **7% of dementia cases at the population level** — higher than the estimates assigned individually to smoking, physical inactivity, obesity, diabetes or excessive alcohol use. d Health Organization has since reinforced much of the same message. Its updated dementia prevention guidelines, released in July 2026, specifically recommend managing high cholesterol and say hearing aids may form part of dementia risk-reduction strategies. uite a shift in how we need to think about dementia.
Because neither hearing loss nor cholesterol feels particularly neurological.
But the brain does not live separately from the rest of us.
What is good for your heart may also be good for your brain
We have become accustomed to thinking about cholesterol in relation to heart attacks and strokes.
LDL — often called “bad” cholesterol — can contribute to fatty deposits building up in blood vessels. Over time, that can interfere with the healthy circulation on which every organ depends.
Including the brain.
The Lancet Commission specifically identified **high LDL cholesterol in midlife** as a dementia risk factor.
That timing matters.
Dementia may become visible late in life, but many of the processes contributing to it can begin decades earlier.
This is one reason I think we need to move away from the idea that brain health is something we start worrying about at 75.
It is life-course health.
Blood pressure matters.
Blood sugar matters.
Movement matters.
Smoking matters.
Cholesterol matters.
As the WHO memorably put it when issuing its earlier dementia prevention guidelines: what is good for the heart is also good for the brain. sn’t mean everyone with high cholesterol will develop dementia. Far from it.
Risk factors aren’t destiny.
They simply alter probabilities.
And that distinction is important, because dementia is one of those subjects where statistics can quickly become frightening rather than useful.
The point of identifying modifiable risk isn’t to make us anxious.
It’s to show us where we still have some influence.
Hearing loss is an even more surprising part of the story
Hearing loss feels different.
If you can’t hear well, surely that’s an ear problem?
Apparently, it isn’t quite that simple.
WHO now explicitly states that unaddressed hearing loss is associated with an increased risk of dementia and accelerated cognitive decline. ers are still working out exactly why.
There are several plausible explanations, and they may overlap.
When hearing becomes difficult, the brain has to work harder simply to decode conversation. More mental resources may be diverted toward understanding what is being said.
Hearing loss can also gradually change behaviour.
A noisy restaurant becomes tiring.
A large group conversation becomes frustrating.
You stop catching the punchline.
Eventually, perhaps, it feels easier not to go.
And that creates another problem.
Human brains seem to benefit enormously from engagement — conversation, relationships, stimulation, novelty and participation in the world around us.
Hearing loss can quietly chip away at all of them.
WHO lists social isolation and cognitive effects among the consequences of unaddressed hearing loss. ins as difficulty hearing may therefore become something much larger.
The important word is *unaddressed*
There is a nuance here that matters enormously.
Hearing loss itself is often not reversible.
Age-related hearing loss, for example, commonly results from degeneration of sensory cells in the ear. WHO says it cannot usually be reversed, although it can be managed effectively with hearing aids and other communication devices. we say hearing loss is “treatable”, what we really mean is that **its effects can often be managed**.
And that management may matter.
Hearing aids are not a magic shield against dementia, and the evidence does not justify telling people that wearing one will prevent Alzheimer’s disease.
But the direction of the research is encouraging enough that WHO’s newest guidelines say hearing aids may be offered as part of a dementia risk-reduction strategy. a significant recommendation.
Particularly because hearing loss is so often minimised.
People adapt.
Partners repeat themselves.
The television gets louder.
Family members learn which side to sit on.
And slowly everyone accommodates the problem rather than addressing it.
Sometimes that works surprisingly well.
Until it doesn’t.
Dementia prevention is becoming less mysterious
For many years, dementia carried a terrible sense of inevitability.
Your parents had it.
You got older.
You waited.
There is still a great deal we cannot control, including age and genetics.
And even someone who follows every piece of health advice imaginable can develop dementia.
But that’s only part of the story now.
The Lancet Commission’s estimate that potentially modifiable factors are associated with around 45% of dementia cases doesn’t mean 45% of individual cases could definitely have been prevented.
Population statistics don’t work that way.
But it does mean that a substantial proportion of dementia risk appears connected to things societies and individuals can potentially influence.
The full list is remarkably ordinary: education, hearing loss, high LDL cholesterol, depression, traumatic brain injury, physical inactivity, diabetes, smoking, high blood pressure, obesity, excessive alcohol consumption, social isolation, air pollution and untreated vision loss. no exotic brain supplement on that list.
No miracle food.
No expensive anti-ageing treatment.
Instead, much of dementia prevention increasingly looks like looking after the ordinary machinery of a human life.
Move your body.
Stay connected.
Protect your hearing.
Treat your blood pressure.
Check your cholesterol.
Don’t smoke.
Keep learning.
Look after your eyes.
And address health problems rather than assuming they’re simply part of getting older.
Perhaps we need to redefine “brain health”
This is the part I find most interesting.
We tend to divide ourselves into pieces.
Heart health.
Mental health.
Hearing.
Vision.
Fitness.
Brain health.
But our bodies don’t respect those categories nearly as much as we do.
A hearing problem can alter how much we participate socially.
A cardiovascular problem can affect the blood vessels supplying the brain.
Depression can change behaviour, activity and connection.
Poor vision can shrink someone’s world.
Everything connects.
And perhaps that’s the more hopeful message behind this research.
Looking after our brains as we age may not require us to obsess about dementia.
It may simply require us to pay attention to our whole lives.
Including the surprisingly mundane things we’d never thought of as brain health at all.
