Dementia Risk Reduction: What the Evidence Says You Can Actually Do Now

Hearing and vision checks, blood pressure, movement, sleep and mood: what the evidence supports for lowering your dementia risk, and what is still experimental.

The single most useful thing you can do about dementia risk is not a scan or a supplement. It is finding and correcting the boring, modifiable things that quietly wear the brain down: hearing loss, high blood pressure, inactivity, poor sleep, low mood and isolation.

The 2024 Lancet Commission estimated that 14 modifiable risk factors together account for up to 45% of dementia cases worldwide. That is a population estimate, not a promise about any one person. But it is the best lever we have, and most of it costs very little.

This follows my article on Alzheimer's blood tests. Testing answers a narrow clinical question. This piece is about what you can start on Monday, whatever any test says.

And it applies to almost everyone. Writing in Nature Reviews Neurology in September, Dr Htet Lin Htun and Professor Kaarin Anstey of UNSW argue that a low risk profile is now the exception, not the rule. One Danish study of nearly 90,000 adults aged 65 and over found just 5% had none of 16 modifiable risk factors. Waiting to be labelled "high risk" before acting makes little sense when almost all of us carry something worth addressing.

The evidence tiers, plainly

I use three labels in clinic and I will use them here. Proven means the link with dementia is well established, and acting on it is good medicine for other reasons too. Promising means the signal is consistent but less certain. Experimental means we do not know enough to recommend it for dementia prevention.

One honest caveat sits over the whole table. Very few interventions have trial evidence that they prevent dementia itself. "Proven" here means proven risk factor, not proven cure.

Read that table again. Almost everything near the top is cheap, low risk and bookable this week. The further down you go, the louder the marketing tends to get.

Hearing, vision and smell: the input problem

Your brain is not a passive receiver. It is constantly working with incoming sound and light to build a model of the world, and that work keeps networks active and connected. Reduce the input and you reduce the workload.

Hearing loss is one of the largest modifiable risk factors in the Lancet Commission's modelling. The proposed pathways are plausible: less stimulation, social withdrawal, and the extra effort of straining to follow speech.

The trial evidence is encouraging but not a slam dunk. In the ACHIEVE trial, hearing intervention did not slow cognitive decline across all participants. It did slow decline by close to half in a higher risk subgroup. That is a real signal, not proof that hearing aids prevent dementia for everyone.

So the practical question is simple. When did you last have your hearing checked? Most adults over 50 cannot answer that. Hearing loss creeps in over years, and the person who has it is usually the last to notice. An audiogram is cheap, quick and non invasive. If there is a loss, hearing aids are not a vanity purchase. They are an input restoration device.

Vision is the same story with a shorter evidence trail. Untreated vision loss was added to the Lancet list of modifiable risk factors in 2024. Whether correcting it lowers dementia risk still needs trials, but untreated vision problems also raise your risk of falls. Get your eyes checked. It is not glamorous. It is sensible.

What about your sense of smell?

Patients ask about this, and the research is genuinely interesting. The brain regions that handle smell are among the first affected in Alzheimer's disease. A 2024 meta-analysis of longitudinal studies found the risk of cognitive decline rose by about 18% for every 10% drop in smell test scores.

But smell is a marker, not a lever. Smell loss has many causes, including ageing, smoking, sinus disease and viral infections such as COVID-19. No treatment for smell loss has been shown to change dementia risk, and smell testing is not a validated screening tool for well people. It belongs in the "interesting, not yet actionable" bucket. If you have noticed a persistent change in smell alongside memory or thinking concerns, mention both to your doctor.

The lifestyle levers that actually move the needle

If I had to compress the lifestyle evidence into a short list, it would look like this.

• Move, and move with some intensity. Higher cardiorespiratory fitness is associated with lower dementia risk in large cohort studies, and the association holds across populations. Aim for regular aerobic activity and at least two strength sessions a week. Start where you are, not where you think you should be.

• Know and treat your blood pressure. Midlife hypertension is one of the best established modifiable risk factors. In the SPRINT MIND trial, intensive blood pressure control reduced mild cognitive impairment. Have it measured properly and agree a target with your GP.

• Eat for metabolic health. High LDL cholesterol, diabetes and excess weight all sit upstream of vascular health, and vascular health sits upstream of brain health. There is no single magic food. There is a pattern that works.

• Protect your sleep. Poor sleep and untreated sleep apnoea are associated with cognitive decline. If you snore, wake unrefreshed, or have been told you stop breathing at night, get it investigated.

• Look after your mood. Depression is on the Lancet list. It deserves proper assessment and treatment for its own sake, whether or not that changes dementia risk.

• Stay socially and mentally engaged. The evidence is observational and hard to randomise, but the signal is consistent. Isolation is bad for brains. This is one of the few health recommendations that is also enjoyable.

• Do not smoke, keep alcohol moderate, and protect your head. Standard advice, still true. Head injury is a recognised risk factor, so wear the helmet.

None of this is exciting. All of it is measurable and improvable at any age. That is the point.

One more thing worth saying. Risk is also shaped by education, income and access to care, not just personal choices. Having dementia does not mean someone failed to look after themselves.

Where supplements fit, and where they do not

Patients ask about supplements constantly, so let me be straight.

Creatine is the one with the most interesting early data. Some short term studies suggest it may help aspects of cognitive performance, particularly under stress or sleep deprivation, and in some older adults. The effect sizes are modest and the research is early. It is not a dementia prevention strategy, and it does not replace any item in the list above. If you are considering it, that is a conversation for a consultation, not a shopping cart.

Beyond that, the supplement aisle is mostly noise. No over the counter product has robust evidence that it prevents Alzheimer's disease. Correcting a diagnosed deficiency, such as low B12, is a different clinical question.

If someone markets a product for brain protection, ask them for the trial. Not a mechanism. Not a short term memory score. A trial that measured dementia.

The pipeline: real science, real caveats

There is genuine progress in Alzheimer's medicine, and it is worth understanding at a high level. The key distinction is between treating diagnosed disease and preventing it in healthy people. Those are different questions with different answers.

Treatment of early disease. Antibody treatments that clear amyloid from the brain were approved in Australia in 2025. They are for people with mild cognitive impairment or mild dementia due to Alzheimer's, with amyloid confirmed by testing. They modestly slow decline. They are not cures, they are not on the PBS, and they carry real risks, including brain swelling and bleeding that need MRI monitoring. Treatment is specialist led and expensive.

Prevention in people without symptoms. Large trials are now testing whether the same antibody class helps people who have amyloid in the brain but no symptoms yet. Results are not in. Earlier prevention trials of related antibodies did not slow decline, so this is a genuine open question.

The metabolic medicines. There was a lot of hope that the GLP-1 class of diabetes and weight loss medicines might protect the brain. In late 2025, two large phase 3 trials of one of these medicines in early Alzheimer's did not slow progression, even though some blood markers improved. These were treatment trials, not prevention trials, so they do not settle every question. But they are an important counterweight to the hype.

What I will say plainly is this. These are prescription medicines with real side effects and real costs. None is approved for dementia prevention. Whether any medicine suits a particular person is a decision for a consultation with a clinician who knows their history, not an article and certainly not an advertisement.

If you want the honest summary: the pipeline is promising, the risk factor evidence is strong, and the gap between those two words is where most of the marketing lives.

Check your own risk first: CogDrisk

Before you ask anyone about Alzheimer's blood tests or brain scans, there is a better first step. It is free and you can do it tonight.

CogDrisk is an online dementia risk assessment developed by Neuroscience Research Australia (NeuRA) and UNSW Sydney. The project is led by Professor Kaarin Anstey, the same researcher arguing that almost none of us are low risk. Dementia Australia points people to it as well.

It asks about your health, lifestyle and environment, then gives you a personalised report. The useful part is not the number. It is the two columns: what you are already doing well, and where there is room for improvement, with practical recommendations for each.

A few things to know before you start:

• It is a risk factor questionnaire, not a test. It cannot tell you whether you have Alzheimer's disease, and the score is not a percentage chance of developing dementia.

• Scores are projected for midlife. If you are under 65, your score reflects the profile you would have if you kept your current habits to 65 and beyond.

• It does not ask about hearing or vision. Check those separately, as above.

• Even fit, healthy people get flags. Sleep, mood and social connection are the ones that tend to surprise people. That is the point of doing it.

Then take the report to your doctor. It turns a vague worry into a specific conversation: which of these can I realistically change, and is any further testing actually worth doing for me? For anything individual or more specific, that conversation with your own doctor is where it belongs.

What to do this month

Forget the perfect protocol. Do the cheap, high yield things first.

1. Complete CogDrisk and save the report.

2. Book a hearing test if you have not had one in the last few years.

3. Book an eye check.

4. Get your blood pressure measured properly, and your cholesterol and glucose checked with your GP.

5. Look at your week and find two slots for movement. Put them in the calendar.

6. If your sleep or mood is poor, say so out loud to a clinician rather than accepting it.

7. Put one regular social commitment in the diary and keep it.

That list will do more for your brain than any product you can buy online. It is also, frankly, less interesting to talk about at dinner. That is usually how you can tell it is real.

FAQ

Can dementia actually be prevented? No single intervention has been proven to prevent Alzheimer's disease. What the evidence supports is risk reduction: addressing factors like hearing loss, blood pressure, fitness and mood is associated with lower risk in large studies. That is a meaningful difference, and it is worth acting on.

Does hearing loss really increase dementia risk? It is one of the largest modifiable risk factors in dementia prevention research, and the association is consistent across studies. A major trial found treatment slowed decline in higher risk people, though not in everyone. The intervention is low risk and improves communication regardless. That combination is why it sits near the top of my list.

Is losing my sense of smell an early sign of Alzheimer's? Smell loss is linked with later cognitive decline in research, but it has many common causes and is not a screening test on its own. If it comes with memory or thinking changes, raise both with your doctor.

Should I take creatine for my brain? There are some early, modest signals for cognitive performance in short term studies. It is not a dementia prevention strategy and does not replace exercise, sleep, blood pressure control or treating hearing loss. Whether it suits you is a conversation for a consultation.

Are the new dementia drugs available? Some antibody treatments are now approved in Australia for people with early, diagnosed Alzheimer's disease and confirmed amyloid. They are specialist led, expensive and not approved for prevention. Prevention trials are still running.

Is CogDrisk a test for Alzheimer's? No. It assesses your risk factors and gives you a personalised report. It does not diagnose anything. Use it to start a conversation with your doctor, not to rule disease in or out.

Should I get an Alzheimer's blood test? For most well people without symptoms, not yet. My earlier article explains why. Start with your risk factors.

General information, not individual medical advice. Speak to your own doctor.

References

1. Livingston G, Huntley J, Liu KY, et al. Dementia prevention, intervention, and care: 2024 report of the Lancet standing Commission. Lancet. 2024;404(10452):572–628. PMID: 39096926.

2. Htun HL, Anstey KJ. Commentary on dementia prevention and population risk. Nature Reviews Neurology. 2026.

3. Hoffman L. Time to shift our approach to dementia prevention, as very few of us are "low risk", experts say. Healthed. 30 September 2026.

4. Danish population study of 16 modifiable dementia risk factors in adults aged 65 and over. Journal of Prevention of Alzheimer's Disease. 2025.

5. 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 (ACHIEVE). Lancet. 2023;402(10404):786–797. PMID: 37478886.

6. Williamson JD, Pajewski NM, Auchus AP, et al. Effect of intensive vs standard blood pressure control on probable dementia (SPRINT MIND). JAMA. 2019;321(6):553–561. PMID: 30688979.

7. Yeo BSY, Song HJJMD, Tan BKJ, et al. Olfactory impairment and incident cognitive decline: a systematic review and meta-analysis. 2024.

8. Avgerinos KI, Spyrou N, Bougioukas KI, Kapogiannis D. Effects of creatine supplementation on cognitive function of healthy individuals: a systematic review of randomized controlled trials. Experimental Gerontology. 2018;108:166–173.

9. Attwooll J. TGA approval of a second amyloid antibody for early Alzheimer's disease. newsGP, RACGP. 25 September 2025.

10. How to efficiently move towards primary prevention in sporadic AD. Alzheimer's & Dementia. 2025.

11. Novo Nordisk. Evoke phase 3 trials did not demonstrate a statistically significant reduction in Alzheimer's disease progression. Company announcement, 24 November 2025.

12. NeuRA and UNSW. CogDrisk: Cognitive Health and Dementia Risk Assessment. cogdrisk.neura.edu.au