Wellness · Healthy ageing
Cognitive health, 14 modifiable risks, 45% of dementia.
The Lancet Commission puts numbers on it — cognitive decline is not inevitable. Here is what actually helps.
Why trust this guide
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Clinically reviewed
Written by our editorial team and reviewed by a registered UK clinician before publication.
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Sourced from the Lancet Commission
Every claim is checked against the 2024 Lancet Commission on Dementia, NICE and NHS guidance you can see at the end.
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Practical, not preachy
Real changes you can make this decade — no vague advice, no supplement upsells.
Key facts
Cognitive health at a glance.
The headline numbers from the 2024 Lancet Commission, the levers that matter most, and when to escalate.
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The headline number
The Lancet Commission identifies 14 modifiable dementia risk factors accounting for ~45% of dementia risk.
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The full list
Top modifiable factors: education, hearing loss, high LDL, hypertension, obesity, smoking, depression, physical inactivity, diabetes, alcohol, TBI, air pollution, social isolation, uncorrected vision loss.
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Not inevitable
Cognitive decline is NOT inevitable — a large fraction of risk sits inside habits and health metrics we can act on.
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The biggest levers
Sleep, exercise, blood pressure, hearing correction and social connection are the biggest levers.
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Start at midlife
The evidence is strongest for changes made in your 40s, 50s and 60s — but earlier and later still help.
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When to escalate
Memory change affecting daily life — see your GP.
Why this guide matters
Small habits, real brains.
Cognitive-health advice online is noisy and often contradictory. The three points below shape everything else on this page.
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Prevention starts at midlife
The evidence is strongest for changes made in your 40s, 50s and 60s — but earlier and later still help.
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Hearing loss is the top modifiable factor
A hearing test at 55+ and hearing aids where indicated are one of the highest-value interventions available.
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Sleep, BP, social — three of the biggest levers
Fixing these three does more than any supplement or brain-training app.
The evidence
The levers that actually move cognitive risk.
A pragmatic order to work through — the biggest levers first, the fine-tuning last.
Phase 1 · Anchors
Hearing, blood pressure, social connection
Phase 2 · Habits
Exercise and sleep
Phase 3 · Fine-tune
Diet and alcohol
- 01
Anchors
Address hearing loss early
The single biggest modifiable factor in the Lancet analysis — a hearing test at 55+ and hearing aids where indicated.
- 02
Anchors
Treat blood pressure aggressively
Target systolic <130 mmHg in midlife where safe — this is one of the highest-impact levers.
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Anchors
Get social connection right
Loneliness and isolation are independent risk factors. Regular real-world contact is protective.
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Habits
Regular aerobic + strength exercise
150 minutes moderate aerobic per week plus two strength sessions — the single best whole-brain intervention.
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Habits
Adequate sleep
7-9 hours, consistent timing. Poor sleep is associated with amyloid clearance problems.
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Fine-tune
Mediterranean-style diet
Plants, olive oil, fish, nuts and legumes. Robust cohort evidence for cognitive protection.
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Fine-tune
Manage alcohol
No safe level for the brain — less is better. Consider going alcohol-free or well below 14 units/week.
Typical timeline: years of steady habits — this is a decades-long project, not a sprint.
Signs it affects you
Where your modifiable risk usually sits.
A quick self-check across the biggest modifiable factors. A pattern here is a nudge to act.
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Hearing loss
The single biggest modifiable factor — correcting it is protective.
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High blood pressure
Sustained hypertension damages the small vessels that feed the brain.
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Social connection
Loneliness and isolation are independent risk factors.
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Sleep
Chronically poor sleep is associated with higher dementia risk.
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Physical activity
Inactivity is a leading modifiable factor — movement is treatment.
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Diet
A Mediterranean-style pattern is the best-evidenced eating pattern.
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Alcohol
No safe level for the brain — less is genuinely better.
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Red flag: memory change affecting daily life
If new forgetfulness is disrupting work or home, see your GP.
How to do it
Practical changes that add up.
Eight steps, in rough order of impact — pick the ones that fit your life and stack them over months and years.
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Get a hearing test at 55+
The single biggest modifiable factor — free NHS tests are widely available. Use hearing aids if recommended.
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Blood-pressure control
Know your numbers. Target systolic <130 mmHg in midlife where safe. Retest yearly at minimum.
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Regular activity
150 minutes moderate aerobic per week plus two strength sessions. Walking counts.
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Sleep hygiene
7-9 hours, consistent wake time, cool dark bedroom. See our sleep hygiene guide.
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Mediterranean-style diet
Plants, olive oil, fish, nuts, legumes. Limit ultra-processed food.
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Learn something new (novelty)
A new language, instrument or skill builds cognitive reserve — the effect is dose-dependent.
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Social engagement
Weekly real-world contact, ideally in a role or group where you are needed.
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Stop smoking, moderate alcohol
Two of the clearest modifiable levers — both effects are reversible over time.
What this guide is based on
The sources behind every claim on this page.
The Lancet Commission on Dementia and UK national guidance, current at the time of last review.
Key references
Guidelines and standards we relied on.
A quiet reminder
This guide is for information, not medical advice.
If you or a family member have noticed a memory change affecting daily life, please see your GP — early assessment is worthwhile.
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Lancet Commission. Dementia prevention, intervention and care: 2024 report.
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NHS. Dementia — risk factors and prevention.
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Alzheimer's Society. Reducing your risk of dementia.
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NICE NG97. Dementia: assessment, management and support.
Red flags
When it is not just normal ageing.
These signs suggest an underlying problem worth investigating. Prevention alone will not address them — see a GP.
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Getting lost in familiar places
Losing your way on a route you know well is not normal ageing — see your GP.
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Confusion about time or place
Losing track of the date, season or where you are warrants assessment.
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Word-finding beyond occasional
Frequent, obvious difficulty finding common words — worth investigating.
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Personality change
New irritability, apathy or disinhibition noticed by those close to you.
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Falls with head injury
Traumatic brain injury is itself a modifiable risk factor — take falls seriously.
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Depression in later life
Overlaps significantly with cognitive decline and is treatable — see a GP.
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Family observations of change
People close to you often notice cognitive change before you do. Take it seriously.
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Vision or hearing loss + cognitive dip
Uncorrected sensory loss accelerates decline — correct both, then reassess.
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Any thoughts of self-harm
Please contact the Samaritans on 116 123 or your GP urgently.
Making it stick
A steady rhythm, for decades.
Four principles to keep the changes going once the novelty wears off.
A quiet reminder
Consistency beats intensity, every time.
Small, steady changes — kept up for years — do more than a heroic month that does not last.
- 01 Timing
Prevention starts at midlife
The evidence is strongest for changes made in your 40s, 50s and 60s — but earlier is better and later still helps.
- 02 Hearing
Hearing correction is huge
The biggest single modifiable factor. A hearing test is quick, free on the NHS, and hearing aids are transformative.
- 03 Connection
Social connection is treatment
Weekly meaningful contact is protective in its own right. Treat it with the same seriousness as exercise.
- 04 Compounding
Small habits compound
No single change transforms risk. Six modest habits, kept up for years, do more than any pill.
Frequently asked
Everything we get asked about cognitive health.
Quick answers on prevention, brain training, sleep, menopause, alcohol, hearing aids, statins and when to see a GP.
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Can I prevent dementia?
You cannot guarantee prevention, but you can reduce risk substantially. The 2024 Lancet Commission estimates ~45% of dementia risk sits in 14 modifiable factors.
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What are the biggest modifiable risks?
The Lancet Commission identifies 14 factors: education, hearing loss, high LDL, hypertension, obesity, smoking, depression, physical inactivity, diabetes, alcohol, traumatic brain injury, air pollution, social isolation and uncorrected vision loss.
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Does brain training help?
The effects are small and largely task-specific — you get better at the training itself. Real-world novelty (a new language, instrument or skill) is more likely to build durable cognitive reserve.
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Sleep and dementia — real link?
Yes. Chronically poor sleep is associated with higher dementia risk, likely via impaired clearance of amyloid and other by-products. Fix the fundamentals — see our sleep hygiene guide.
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Menopause and cognition?
Cognitive symptoms during the perimenopause are common and usually resolve. HRT may help symptoms and there is emerging evidence for cognitive benefit — discuss with your GP.
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What about alcohol?
There is no safe level for the brain — less is better. Well below the UK 14 units/week guidance is sensible, and alcohol-free is a reasonable choice.
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Hearing aids — how much difference?
Big. Hearing loss is the single biggest modifiable factor in the Lancet analysis, and correcting it is associated with meaningful risk reduction.
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Language learning?
A well-evidenced way to build cognitive reserve. The benefit comes from sustained, effortful learning — a few weeks of an app is not enough.
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Statins and cognition?
The evidence is reassuring — statins do not appear to harm cognition and may reduce vascular dementia risk. Continue if prescribed.
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When should I see a GP?
Any memory change affecting daily life — getting lost in familiar places, confusion about time or place, or family members noticing a change. Early assessment is worthwhile.
Related content
Keep reading.
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Hearing test
The single highest-value cognitive-health intervention over 55.
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High blood pressure
One of the biggest modifiable dementia risk factors — know your numbers.
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Purpose & connection
Social engagement is protective in its own right.
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