Guide · Latest research · 8 min read
Reducing dementia risk: the 14 factors that matter
The Lancet Commission on dementia concluded that up to 45% of cases worldwide are associated with 14 modifiable risk factors. That figure is a population estimate, not a personal guarantee — but every item on the list is something a family can actually act on.
01. Hearing loss
One of the largest single contributors in mid-life. Straining to hear withdraws people from conversation and starves the brain of stimulation. Get a hearing test; wear the aids. Trials suggest the benefit is greatest in people already at higher risk.
02. Untreated vision loss
Added to the list in 2024. Cataract surgery and up-to-date glasses are among the cheapest, fastest interventions available.
03. High LDL cholesterol in mid-life
Also added in 2024. Worth a conversation with the GP or PCP about a lipid check and whether treatment is warranted.
04. High blood pressure
From your forties onwards, treating hypertension is one of the best-evidenced things you can do for your brain — not just your heart.
05. Smoking
Stopping helps at any age. Risk starts falling within a few years.
06. Obesity
Mid-life weight matters more than later-life weight. Unintended weight loss in older age is a different signal — get it checked.
07. Physical inactivity
The threshold is lower than people assume. Regular brisk walking counts; consistency beats intensity.
08. Excess alcohol
More than about 21 units a week (roughly 14 US standard drinks) raises risk measurably.
09. Depression
Both a risk factor and an early symptom. Treat it either way — it's one of the most under-treated things in older adults.
10. Social isolation
Loneliness is a genuine, measurable brain-health risk. A weekly group, a regular call, a lunch club — mundane and effective.
11. Diabetes
Good glucose control protects small blood vessels in the brain as well as everywhere else.
12. Traumatic brain injury
Helmets, and taking falls prevention seriously in the over-65s. A hip fracture and a head injury often arrive together.
13. Air pollution
Largely a policy issue, but indoor air matters too — ventilation, and avoiding wood-burning stoves in poorly ventilated rooms.
14. Less education in early life
Not something you can change retrospectively, but continued learning at any age builds cognitive reserve. Adult classes count.
"My mum already has dementia — is any of this relevant?"
Yes, more than most people expect. These factors don't only affect whether dementia starts; several affect how well someone functions with it. Correcting hearing and vision reduces confusion, agitation and hallucinations. Treating depression, pain, blood pressure and sleep apnoea improves day-to-day cognition. Staying active and socially connected slows functional decline. None of this reverses the disease — but it is the difference between a difficult year and an unbearable one.
Six things worth doing this month
- Book a hearing test and an eye test for the person you care for — both are often years overdue and both change daily life immediately.
- Ask for a medication review, specifically for anticholinergic burden. Some bladder, sleep and allergy medicines measurably worsen confusion in older adults, and there are usually alternatives.
- Get blood pressure, cholesterol and HbA1c checked and actually treated to target.
- Protect sleep. Poor sleep and untreated sleep apnoea are increasingly linked to faster cognitive decline; snoring plus daytime sleepiness is worth reporting.
- Falls-proof the house — rails, lighting on the stairs and landing, no loose rugs, and a strength-and-balance class.
- Keep them in company. One fixed social commitment a week does more than any supplement on the shelf.
And for you, the carer
Family carers score badly on almost every one of these factors — isolation, inactivity, poor sleep, skipped health checks, delayed hearing tests. Looking after your own brain is not a self-indulgence when you are the plan. Book your own appointments while you're booking theirs.