Dementia Prevention: What to Do at Every Age

A new generation of blood biomarkers is changing how we think about dementia prevention. A recent Lancet article highlighted how Alzheimer-related bloo

d markers may detect risk years before symptoms appear [1].

A 2026 Nature Medicine study showed that plasma p-tau217 clocks could estimate the likely timing of symptomatic Alzheimer’s disease several years before onset [2].

This matters because dementia prevention is no longer just about reacting once memory problems begin. It is increasingly about identifying risk earlier, then using that window to act.

The 2024 Lancet Commission estimated that 45.3% of dementia cases worldwide may be preventable or delayable by reducing 14 modifiable risk factors across life [3]. These include hearing loss, high LDL cholesterol, hypertension, smoking, obesity, diabetes, depression, physical inactivity, excess alcohol, traumatic brain injury, air pollution, social isolation, untreated vision loss and limited education.

Importantly, the evidence is not only observational. The FINGER study - a 2-year randomised controlled trial of 1,260 at-risk older adults, tested a combined programme of diet, exercise, cognitive training and vascular risk monitoring. Participants receiving the multidomain intervention had better cognitive outcomes than those receiving general health advice alone [4]. This supports a practical message: brain health is not about one magic intervention. It is about combining the basics and doing them consistently.

This does not mean any individual can guarantee they will avoid dementia. It means that, at a population level, a large proportion of dementia risk flows through pathways we can influence.

The practical question is: what should we do, and when?

Childhood and adolescence: Build brain reserve

The earliest stage of dementia prevention is not a blood test or a supplement. It is education, learning and brain development.

The Lancet Commission identifies limited education as one of the major early-life risk factors for dementia [3]. The likely explanation is cognitive reserve: the more resilient and adaptable the brain becomes earlier in life, the better it may cope with later-life pathology.

Practical actions:

🎓 Stay engaged in education and learning

Reading, school, training, music, problem-solving and cognitively challenging hobbies all help build cognitive reserve.

🎧 Protect hearing early

Use ear protection at loud concerts, music venues, workshops or when using power tools.

🚴 Prevent head injury

Wear helmets where appropriate, use seatbelts, and take concussion/return-to-play advice seriously.

🏃 Build movement habits early

Encourage daily activity, sport, walking, cycling or active play.

🚭 Stay smoke-free from the start

Avoiding smoking protects the brain, lungs, heart and blood vessels.

The added benefits are obvious: better mental health, better employment prospects, better physical fitness and lower lifetime cardiovascular risk.

Young adulthood: Protect the brain from avoidable damage

Young adulthood is where long-term habits start to compound. Alzheimer’s disease may feel distant, but vascular risk, smoking exposure, alcohol patterns, head injury and poor fitness can begin decades before symptoms.

Smoking is consistently associated with increased dementia risk. In the Lancet model, smoking remains one of the key modifiable contributors [3]. Quitting is likely to reduce risk over time, and the cardiovascular benefits begin quickly.

Practical actions:

🚭 Do not smoke — and quit fully if you do

Smoking increases vascular and dementia risk. Stopping is one of the most powerful long-term health decisions.

💪 Exercise most days

Aim for a mix of aerobic exercise and strength training. Fitness supports brain, heart, metabolic and mental health.

🍺 Keep alcohol low

Avoid binge drinking and build in alcohol-free days. Lower alcohol intake benefits sleep, blood pressure, liver health and cancer risk.

🧠 Treat depression, anxiety and poor sleep early

Mood and sleep problems affect activity, social connection, motivation and long-term brain health.

🪖 Avoid repeated head injury

Take concussion seriously, especially in sport, cycling, manual work or high-risk activities.

These are not just “brain health” actions. They reduce risk of heart disease, stroke, diabetes, cancer, liver disease and poor mental health.

Early midlife: Know your numbers

Midlife is probably the most important period for vascular dementia prevention. This is when blood pressure, cholesterol, glucose, weight and lifestyle exposures begin to have a major cumulative effect on the brain.

The 2024 Lancet Commission added high LDL cholesterol as a dementia risk factor and highlighted its importance from around midlife [3]. Hypertension, diabetes, obesity and smoking are also key modifiable risks.

 A large South Korean study published in Journal of Neurology, Neurosurgery & Psychiatry found that people with LDL cholesterol below 1.8 mmol/L had a 26% lower risk of dementia and 28% lower risk of Alzheimer’s disease compared with those with LDL above 3.4 mmol/L [5]. This does not prove cause and effect, but it strongly supports a practical message: know your cholesterol early, treat high LDL appropriately, and see lipid control as part of both heart and brain prevention.

Practical actions:

🩺 Check your blood pressure

High blood pressure is one of the clearest modifiable risks. Don’t ignore “slightly high” readings.

🧬 Know your LDL cholesterol

High LDL cholesterol is now recognised as an important midlife dementia risk factor, as well as a major cardiovascular risk factor.

🩸 Check glucose or HbA1c if at risk

Preventing or managing diabetes protects blood vessels throughout the body, including the brain.

🥗 Eat for brain and heart health

Choose a Mediterranean-style pattern: vegetables, legumes, nuts, olive oil, fish, wholegrains and fewer ultra-processed foods.

👂 Act on hearing changes early

If you are struggling to hear conversations, get assessed. Don’t wait years before considering hearing support.

Blood pressure control has some of the strongest intervention evidence for protecting brain health. In the original SPRINT-MIND trial, intensive blood pressure control reduced the risk of mild cognitive impairment, although the reduction in probable dementia alone did not reach statistical significance [6]. Longer-term follow-up from SPRINT-MIND has strengthened the case that sustained blood pressure control may help reduce later cognitive impairment and dementia risk [7].

The co-benefits are substantial: fewer strokes, fewer heart attacks, less kidney disease, better metabolic health and lower vascular ageing.

Later midlife: Treat risk factors aggressively

Later midlife is where prevention should become more proactive. This is not the time for “watchful waiting” with high blood pressure, poor diabetes control, hearing loss or rising cholesterol.

The FINGER trial showed that combining diet, exercise, cognitive training and vascular risk monitoring can help maintain cognitive function in at-risk older adults [4]. The lesson is simple: do not rely on one habit alone. The biggest opportunity is combining movement, healthy eating, blood pressure/cholesterol/glucose control, mental stimulation and social connection.

Hearing loss is one of the largest potentially modifiable dementia risks in the Lancet model [3]. It may increase cognitive load, reduce social interaction and contribute to isolation. The ACHIEVE trial found that hearing intervention did not significantly reduce cognitive decline in the whole study population, but it did slow decline in a higher-risk subgroup [8].

Practical actions:

🩺 Tighten blood pressure control

This is not the stage for “watchful waiting” with persistently high readings.

🩸 Manage diabetes actively

Good diabetes care protects the brain, kidneys, eyes, nerves and heart.

⚖️ Reduce visceral weight gain

Waist gain, insulin resistance, sleep apnoea and fatty liver all overlap with vascular brain risk.

💪 Keep strength, balance and fitness in the routine

Do not just focus on cardio. Strength and balance help protect mobility, independence and frailty risk.

👂👁️ Check hearing and vision

Treating hearing loss, cataracts and vision problems can improve confidence, social connection and function.

This is also a good stage to consider dementia risk in a more structured way, especially for people with strong family history, APOE-related risk, cardiovascular disease, diabetes, hearing loss or subjective cognitive concerns.

Older adulthood: Preserve function, senses and connection

Older age is not too late. Dementia risk reduction still matters, but the focus shifts slightly: preserve mobility, treat sensory loss, prevent isolation and identify cognitive change early.

The Lancet Commission added untreated vision loss as a modifiable risk factor in 2024 [3]. Social isolation is also a major contributor. These are practical, everyday issues that affect quality of life long before dementia is diagnosed.

Practical actions:

🚶 Move every day

Walking, gardening, swimming, cycling or chair-based exercise all count. The key is avoiding long sedentary stretches.

🏋️ Add strength and balance work

Simple sit-to-stands, resistance bands, stairs, balance drills or supervised classes can protect independence.

👂👁️ Treat hearing and vision loss quickly

Sensory loss can increase isolation, reduce activity and make everyday life more cognitively demanding.

🤝 Protect social connection

Schedule regular calls, meals, clubs, volunteering, faith groups, classes or shared activities.

🧠 Act early on memory or function changes

Persistent memory concerns, missed bills, medication errors, getting lost or family concern should prompt proper assessment.

Blood biomarkers such as p-tau217 may become increasingly useful in symptomatic patients or selected high-risk groups [2]. But they should not yet be seen as a general screening test for every healthy older adult.

The big picture

The old story was that dementia was simply an inevitable consequence of ageing or genetics.

That story is no longer accurate.

Modern dementia prevention is about acting earlier, often decades before symptoms. It is about protecting blood vessels, metabolism, hearing, vision, mood, sleep, movement, social connection and cognitive reserve.

The message is not: “you can guarantee dementia will not happen.”

The message is better than that: there are meaningful, evidence-based actions that can reduce risk, delay onset and improve overall health at the same time.

That is a powerful shift — for patients, clinicians and public health.

References

1. Jiang X, Hoang TD, Shaw LM, Jacobs DR Jr, Nasrallah IM, Bryan RN, et al. Alzheimer’s disease neuropathology plasma biomarkers and cognition in midlife: a community-based cohort study. The Lancet. 2026;407(10544):2208–2216. https://doi.org/10.1016/S0140-6736(26)00515-5

2. Petersen KK, Milà-Alomà M, Li Y, et al. Predicting onset of symptomatic Alzheimer’s disease with plasma p-tau217 clocks. Nature Medicine. 2026;32(3):1085–1094. https://doi.org/10.1038/s41591-026-04206-y

3. Livingston G, Huntley J, Liu KY, et al. Dementia prevention, intervention, and care: 2024 report of the Lancet Standing Commission. The Lancet. 2024;404:572–628. https://doi.org/10.1016/S0140-6736(24)01296-0

4. Ngandu T, Lehtisalo J, Solomon A, et al. A 2-year multidomain intervention of diet, exercise, cognitive training, and vascular risk monitoring versus control to prevent cognitive decline in at-risk elderly people (FINGER): a randomised controlled trial. The Lancet. 2015;385(9984):2255–2263. https://doi.org/10.1016/S0140-6736(15)60461-5

5. Lee YB, et al. Low-density lipoprotein cholesterol, statin therapy and risk of dementia. Journal of Neurology, Neurosurgery & Psychiatry. 2025;96(10):981–989. https://jnnp.bmj.com/content/96/10/981

6. Williamson JD, Pajewski NM, Auchus AP, et al. Effect of Intensive vs Standard Blood Pressure Control on Probable Dementia: A Randomized Clinical Trial. JAMA. 2019;321(6):553–561. https://pubmed.ncbi.nlm.nih.gov/30688979/

7. Reboussin DM, Gaussoin SA, Pajewski NM, Jaeger BC, Sachs B, Rapp SR, Supiano MA, et al. Long-Term Effect of Intensive vs Standard Blood Pressure Control on Mild Cognitive Impairment and Probable Dementia in SPRINT. Neurology. 2025;104(3):e213334. https://doi.org/10.1212/WNL.0000000000213334

8. Lin FR, Pike JR, Albert MS, et al. Hearing intervention versus health education control to reduce cognitive decline in older adults with hearing loss in the USA: the ACHIEVE randomised controlled trial. The Lancet. 2023;402(10404):786–797. https://doi.org/10.1016/S0140-6736(23)01406-X