2024Lancet
Livingston et al.
International commission
14 changeable risk factors account for about 45% of dementia. Hearing loss and high LDL cholesterol in midlife are the biggest, at 7% each.
Find on PubMed ↗Research library · Mind & mood
Brain health: keeping your memory sharp
Nearly half of dementia cases worldwide could be prevented or delayed by tackling 14 risk factors through life, from hearing loss to high cholesterol. What protects your heart also protects your brain.
Good evidence45%of dementia linked to 14 changeable risk factorsLivingston 2024, Lancet Commission
−50%dementia risk at about 9,800 steps a day; 3,800 steps cut it by 25%del Pozo Cruz 2022, JAMA Neurol, 78,430 adults
−20%new dementia diagnoses over 7 years after the shingles vaccineEyting 2025, Nature, natural experiment in Wales
01
The basics
Building your brain's reserve
Your brain uses about a fifth of your body's energy and depends on a steady blood supply. Damage to small blood vessels, from high blood pressure, diabetes and smoking, is one of the biggest drivers of memory decline.
Alzheimer's disease involves build-ups of proteins called amyloid and tau. During deep sleep, the brain's glymphatic system flushes waste, including amyloid, so poor sleep may speed things up.
People with more cognitive reserve, built through education, challenging work, social life, exercise and good hearing, can carry the same brain changes with fewer symptoms. Hearing loss matters because a brain straining to hear has less capacity left for thinking and memory.
14 risk factors for dementia
Share of dementia worldwide linked to each factor (Lancet Commission 2024). Together they account for about 45%.
02
How it works
What keeps a brain healthy
1
Good blood flow
Healthy blood pressure, sugar and cholesterol protect tiny brain vessels.
2
Deep sleep cleans
The glymphatic system clears waste while you sleep.
3
Use it
Learning, social life and good hearing keep circuits active.
4
More reserve
A well-connected brain copes with ageing for longer.
03
Measure it
Checks that protect your brain
- Hearing test: from 50, or sooner if you struggle in noisy rooms. Untreated hearing loss is the largest single risk factor.
- Eye test: untreated vision loss was added as a new risk factor in 2024.
- Blood pressure and LDL cholesterol: keep top blood pressure under 130 from midlife and treat high LDL.
- Memory worries? A doctor can run a short test such as the MoCA. Low B12, low thyroid, depression and medicines can all cause reversible memory problems.
04
What the research says
The key studies
2022JAMA Neurology
del Pozo Cruz et al.
78,430 adults, wrist trackers
About 9,800 steps a day was linked to 50% lower dementia risk over 7 years; 3,800 steps to 25% lower. Brisk steps mattered most.
Find on PubMed ↗2025Nature
Eyting et al.
280,000+ older adults in Wales
A birth-date cut-off decided who got the shingles vaccine. Those who got it were about 20% less likely to be diagnosed with dementia over 7 years.
Find on PubMed ↗2015Lancet
Ngandu et al. (FINGER)
1,260 older adults, 2 years
A combined programme of healthy diet, exercise, brain training and heart checks improved thinking scores compared with general advice.
Find on PubMed ↗2023Lancet
Lin et al. (ACHIEVE)
977 older adults with hearing loss
Hearing aids and support slowed cognitive decline by 48% over 3 years in people already at higher risk.
Find on PubMed ↗2025JAMA
Baker et al. (US POINTER)
2,111 older adults at risk
A structured 2-year lifestyle programme (exercise, MIND diet, brain training, health checks) improved thinking more than a self-guided version.
Find on PubMed ↗05
Take action
A brain-protection plan
The earlier you start, the bigger the effect, but it's never too late.
- 1
Check your hearing
Get tested and wear hearing aids if you need them. They're now available over the counter in many countries.
- 2
Walk briskly most days
Work up toward 8,000–10,000 steps, with some at a purposeful pace.
- 3
Treat blood pressure and LDL
Keeping both in range protects your brain's blood vessels.
- 4
Sleep 7–8 hours
Get snoring or gasping checked for sleep apnoea.
- 5
Learn hard new things
A language, instrument or dance challenges the brain more than repeat puzzles.
- 6
Helmets and vaccines
Protect your head in sport and cycling, and ask about the shingles vaccine after 50.
06
Myth or fact
Common myths, checked
✕ MythBrain-training apps prevent dementia.
✓ FactMost apps make you better at the app. Real-world learning and social challenge have stronger evidence.
✕ MythDementia is a normal part of ageing.
✓ FactSome slowing is normal; dementia isn't. Many people reach 90+ with sharp minds.
✕ MythIt's all in your genes.
✓ FactThe APOE4 gene raises risk, but people who carry it still benefit from lifestyle changes.
✕ MythCrosswords are enough.
✓ FactThey help a little. Physical activity, hearing and heart health matter far more.
07
Questions
Frequently asked
Should I get tested for APOE4?
It doesn't change prevention advice, and results can cause worry. Talk to a doctor or genetic counsellor first.
Are memory slips normal?
Forgetting a name and remembering later is normal. Getting lost in familiar places or repeating questions isn't. See a doctor.
Do supplements help memory?
No supplement prevents dementia. A daily multivitamin modestly slowed memory ageing in older adults in one set of trials.
08
Sources
References and related topics
- Livingston et al. (2024). Lancet. International commission. PubMed ↗
- del Pozo Cruz et al. (2022). JAMA Neurology. 78,430 adults, wrist trackers. PubMed ↗
- Eyting et al. (2025). Nature. 280,000+ older adults in Wales. PubMed ↗
- Ngandu et al. (FINGER) (2015). Lancet. 1,260 older adults, 2 years. PubMed ↗
- Lin et al. (ACHIEVE) (2023). Lancet. 977 older adults with hearing loss. PubMed ↗
- Baker et al. (US POINTER) (2025). JAMA. 2,111 older adults at risk. PubMed ↗