Dr Voss Gibson•
How to Reduce Your Dementia Risk: The Evidence, and What Actually Works
Dementia can feel like fate — something that either happens to you or doesn't. But landmark research tells a more hopeful story: up to 45% of dementia cases could be prevented or delayed by addressing 14 modifiable risk factors, many of them within your control and many acting in midlife, decades before symptoms would appear. This guide explains what the evidence genuinely shows (and its honest limits), the practical steps that actually protect your brain, why "brain supplements" aren't the answer, and — separately — what everyday "brain fog" usually means, because it's rarely what people fear.
Can Dementia Really Be Prevented?
Let's be precise about a genuinely encouraging finding — and equally honest about what it does and doesn't promise.
The headline finding
In 2024, the standing Lancet Commission on dementia prevention concluded that addressing 14 modifiable risk factors across life could prevent or delay nearly half — up to 45% — of dementia cases worldwide. This built on their earlier work, adding two new factors (high cholesterol and vision loss) as the evidence accumulated. It's one of the most important messages in brain health: a large share of dementia risk isn't fixed.
The honest caveats
That "45%" deserves context, and responsible reporting matters here. It means risk reduction across a population — not a personal guarantee that doing everything right will prevent dementia. Age and genetics still play major roles that we can't change. Individually, addressing any single risk factor might only reduce risk by around 1 to 7 per cent; the power comes from tackling them together. And the science is still evolving — some studies replicating the model have found a more restricted set of factors, a reminder that this is a developing field, not settled certainty.
So the honest framing is this: you can't guarantee you'll never develop dementia, but you can meaningfully shift the odds in your favour — and the steps that do it are the same ones that make you healthier overall. That's a good deal.
The 14 Modifiable Risk Factors for Dementia
Here's the full list from the 2024 Commission, grouped by when in life they matter most:
Early life
- Less education
Midlife (roughly 45–65 — the critical window)
- Hearing loss
- High LDL cholesterol
- Depression
- Head injury (traumatic brain injury)
- Physical inactivity
- Diabetes
- Smoking
- High blood pressure
- Obesity
- Excessive alcohol
Later life
- Social isolation
- Air pollution
- Vision loss
The key insight: midlife matters most
Here's what's easy to miss. Several risk factors — including smoking, depression, physical inactivity and diabetes — were reclassified as midlife factors, meaning they exert most of their influence in your 40s, 50s and early 60s. That's precisely the age when most people (and often their doctors) aren't yet thinking about dementia risk decades away. The takeaway: the best time to act on brain health is earlier than most people assume — now, if you're in midlife.
The powerful reframe
Notice how many factors — blood pressure, cholesterol, diabetes, obesity, inactivity — are cardiovascular. This leads to one of the most useful sayings in medicine: what's good for your heart is good for your brain. Your brain depends on healthy blood vessels, so protecting your cardiovascular health protects your cognition too. That's genuinely motivating, because it means one set of habits pays off twice.
What Actually Works (Your Practical Brain-Health Plan)
The good news: the evidence points to accessible, everyday actions — not exotic interventions. Here's your practical plan:
- Move your body regularly. Physical activity is one of the strongest protective factors, benefiting both heart and brain.
- Protect your cardiovascular health. Keep blood pressure, cholesterol and blood sugar in healthy ranges — this is arguably the highest-impact cluster.
- Get your hearing and vision checked. This is a genuinely underused lever — hearing loss is a leading midlife risk factor, and correcting it (with hearing aids where needed) may reduce risk. Untreated vision loss counts too. Both are easily tested and often easily corrected.
- Stay mentally and socially engaged. Learning, meaningful social contact, and staying connected all build "cognitive reserve" and protect against isolation.
- Prioritise sleep. Poor sleep affects brain health, and untreated sleep apnoea is both common and treatable.
- Look after your mental health. Depression is a modifiable risk factor, and effective help exists.
- Don't smoke, and moderate alcohol.
- Protect your head — wear helmets, prevent falls.
You don't have to do all of these perfectly. Every factor you improve helps, and they reinforce each other.
The Truth About "Brain Supplements"
With brain health trending, you'll see countless supplements promising to boost memory and prevent decline. Here's the honest position: no supplement has been shown to prevent dementia. The "brain health" supplement market is largely built on hope rather than robust evidence, and the money is far better spent on the proven fundamentals above.
There's one distinction worth making. Correcting a genuine nutritional deficiency — such as low vitamin B12, which can cause memory and cognitive symptoms — is a real, medical matter that a doctor can identify and treat. But that's different from taking unproven "brain boosters" as insurance. If you're worried about a deficiency, get tested rather than guessing with supplements.
What Is "Brain Fog" — and Should You Worry?
"Brain fog" — that fuzzy, unfocused, forgetful feeling — is one of the most-searched health complaints, and it worries people who fear it signals dementia. Here's the reassuring reality: everyday brain fog is common and usually not dementia at all. It's typically caused by something identifiable and reversible.
Common causes of brain fog include:
- Poor sleep or undiagnosed sleep apnoea
- Stress, anxiety and burnout
- Perimenopause — a very common and under-recognised cause in women in midlife
- Thyroid problems
- Iron or vitamin B12 deficiency
- Certain medications
- Dehydration, depression, or the after-effects of viral illness
In other words, brain fog is usually a signal to check something treatable — not a sign of impending dementia. Addressing the underlying cause typically clears it.
When memory concerns do warrant a doctor
That said, some changes deserve proper assessment: persistent, worsening memory problems that interfere with daily life, getting lost in familiar places, ongoing difficulty finding words, or noticeable personality changes. These warrant a conversation with a doctor — not to assume the worst, but because assessment often finds a treatable cause, and where it doesn't, earlier support is always better.
When to See a Doctor
To summarise the practical action: see a doctor if you have brain fog that isn't improving despite addressing the likely causes, or memory changes affecting your daily function. And more proactively — if you're in midlife, this is the ideal time to have your blood pressure, cholesterol, blood sugar, hearing and vision checked, precisely because these midlife factors shape your brain health for decades. A midlife health check is one of the most worthwhile things you can do for your future brain.
