On 15 July 2026, the World Health Organization published the second edition of its guidelines on reducing the risk of cognitive decline and dementia, and the headline is encouraging: you can reduce dementia risk, because up to 45% of cases worldwide could be delayed or prevented. A large part of that potential rests on everyday health factors you can actually see on a lab report — your cholesterol, your blood sugar and your blood pressure. In this article you will learn what the new WHO guidelines changed, which blood tests track the risk factors you can act on, and why the guidelines tell you to test before you reach for supplements.
What the new WHO dementia guidelines actually say
The second edition updates advice the WHO first issued in 2019 and folds in years of new evidence. It keeps the central idea that dementia is not simply a matter of age or genes, and it stresses that managing common health conditions across your whole life can lower your risk. For the first time, it adds environmental factors — including reducing exposure to air pollution — and it favours tailored, multi-part prevention plans rather than any single fix. The much-quoted “up to 45%” figure means nearly half of dementia cases are linked to factors that can, in principle, be changed. If the subject is new to you, it helps to first understand the different types of dementia.
The dementia risk factors you can measure in a blood test
Several of the risk factors the WHO highlights are things a routine blood test or a simple blood-pressure reading can reveal long before any memory problem appears. Keeping them in a healthy range protects your heart and, a growing body of research suggests, your brain as well. The table below shows the main ones and how they are checked.
| Risk factor | How it is checked | Why it matters for your brain |
|---|---|---|
| Korkea verenpaine | A blood-pressure reading (the two numbers) | Raised blood pressure in midlife is one of the strongest changeable risk factors |
| High blood sugar or diabetes | Paastoarvo verensokerista ja HbA1c | Long-term high blood sugar is linked to a higher risk of dementia |
| High LDL cholesterol | A lipid panel (LDL, HDL, triglycerides) | Midlife LDL is modestly associated with dementia many years later |
| Low vitamin B12 or vitamin D | A vitamin and nutritional panel | Correcting a genuine deficiency supports nerve and brain health |
| Krooninen tulehdus | Markers such as CRP | Long-running inflammation may contribute to cognitive decline |
These are ordinary tests you may already have on file. To dig into the numbers, read our lipid panel guide, check your cholesterol ratio, understand your glucose levels, review your A1C conversion chart, and read our high blood pressure guide. If blood sugar is your main concern, you can also read our diabetes guide.
Supplements: why the WHO says test first
One of the clearest messages in the new guidelines is what not to do. The WHO does not recommend taking vitamin B, vitamin E, multivitamins or omega-3 supplements just to prevent dementia, unless a blood test shows you genuinely have a deficiency. In plain terms, a supplement only helps if you are truly low — otherwise it adds cost, not protection. That is why checking your levels first makes sense: a simple blood test can show whether your vitamin B12 or vitamin D is low before you buy pills that may do nothing. To see what a nutritional check covers, look at our vitamin and nutritional panel, learn the signs of low vitamin B12, and interpret your vitamin D blood test.
What the latest research adds
The WHO guidelines rest on a large body of recent science. A few findings help explain why the lab numbers above matter — while remembering that most of this evidence shows links, not proof of cause and effect.
A 2024 review in The Lancet Healthy Longevity pooled dozens of studies and found that a handful of common factors — including high blood pressure, hearing loss, physical inactivity and obesity — account for a large share of dementia cases; taken together, a cluster of everyday risk factors was tied to roughly half of cases. What this means for you: no single change is a magic bullet, but stacking several healthy habits genuinely adds up.
A 2025 analysis of hospital records found that people whose LDL (the “bad” cholesterol) was low — under 70 mg/dL — had about a quarter fewer dementia cases than those with high LDL above 130 mg/dL, with a small extra benefit for people taking statins. What this means for you: the LDL number you already get on a standard lipid panel may matter for your brain as well as your heart. It is not a reason to change any medication on your own — that is a conversation to have with your doctor.
A separate 2024 review showed that stroke, dementia and late-life depression share the same changeable risk factors — blood pressure, blood sugar, cholesterol and kidney health among them. What this means for you: one heart-healthy routine, tracked with a few familiar blood tests, pays off in several ways at once. For readers curious about newer diagnostic tools, we also explain the p-tau217 blood test.
Milloin keskustella lääkärin kanssa
Prevention works best when you know your starting point. It is worth booking a check-up if you have never had your blood pressure, blood sugar or cholesterol measured as an adult, if dementia runs in your family and you want a baseline, or if you or those around you notice memory changes. A doctor can order the right tests and, just as important, read them in context. One caution from the WHO and from experts at the 2026 Alzheimer’s Association International Conference: blood biomarker tests for Alzheimer’s are not meant for general-population screening and do not replace a full medical assessment.
Sanasto
| Termi | Määritelmä |
|---|---|
| Dementia | An umbrella term for a lasting decline in memory and thinking that interferes with daily life. |
| Modifiable risk factor | A risk factor you can change, such as blood pressure, unlike age or genes. |
| LDL-kolesteroli | The “bad” cholesterol; high levels can build up inside blood vessels. |
| HbA1c | A blood test showing your average blood sugar over about three months. |
| Lipidipaneeli | A blood test that measures cholesterol and triglycerides. |
| Homokysteiini | An amino acid in blood; high levels have been linked to vascular and brain problems. |
| Cognitive decline | A gradual worsening of memory, attention or thinking speed. |
| Population attributable fraction | The share of cases in a population that might be avoided if a risk factor were removed. |
Usein kysytyt kysymykset
Can you really reduce your dementia risk?
You cannot guarantee you will never develop dementia, but the WHO estimates that up to 45% of cases worldwide are linked to factors you can influence. Habits such as staying active, protecting your hearing, not smoking and managing blood pressure, blood sugar and cholesterol are good for your heart and may help your brain too.
Which blood tests matter for dementia risk?
The most useful everyday tests are a lipid panel for cholesterol, a fasting glucose and HbA1c for blood sugar, and a blood-pressure reading. A vitamin and nutritional panel can be added if you have symptoms or your doctor suspects a deficiency. These do not diagnose dementia; they track risk factors you can act on.
Does high cholesterol raise dementia risk?
Studies suggest that high LDL cholesterol in midlife is modestly associated with a higher risk of dementia years later, and that lower LDL tracks with fewer cases. The evidence shows an association rather than firm proof, but managing cholesterol is already recommended for heart health.
Should I take supplements to prevent dementia?
The WHO advises against taking vitamin B, vitamin E, multivitamins or omega-3 supplements purely to prevent dementia, unless a test shows you have a deficiency. The sensible step is to check your levels first, then supplement only if you are genuinely low.
Does diabetes cause dementia?
Diabetes and long-term high blood sugar are recognised risk factors for cognitive decline and dementia. Keeping blood sugar in a healthy range with diet, activity and, where needed, medication may help lower that risk, though it is not a guarantee.
At what age should I start?
The WHO recommends a life-course approach. Midlife — your 40s and 50s — is an especially important window for blood pressure, cholesterol and blood sugar, but it is rarely too early or too late to make changes that support brain health.
Lähteet
- World Health Organization. Risk reduction of cognitive decline and dementia: WHO guidelines, second edition, 2026. who.int
- National Institute on Aging (NIH). Preventing Alzheimer’s Disease: What Do We Know? nia.nih.gov
- Alzheimers.gov (NIA/NIH). Can I Prevent Dementia? alzheimers.gov
- Stephan BCM, et al. Population attributable fractions of modifiable risk factors for dementia: a systematic review and meta-analysis. The Lancet Healthy Longevity, 2024. doi.org
- Modifiable risk factors for stroke, dementia and late-life depression: a systematic review and DALY-weighted analysis. Journal of Neurology, Neurosurgery & Psychiatry, 2024. doi.org
- Lee M, et al. Low-density lipoprotein cholesterol levels and risk of incident dementia. Journal of Neurology, Neurosurgery & Psychiatry, 2025. consensus.app
Lisälukemista
- Korkea kolesteroli: ymmärrä, ehkäise ja toimi
- The advanced lipid panel
- The Alzheimer blood test in primary care
- Understanding low HDL cholesterol
- Do you really need a comprehensive blood panel
Ymmärrä laboratoriotuloksiasi tekoälyn DiagMen avulla
Your blood pressure, blood sugar and cholesterol are among the few dementia risk factors you can measure and act on — but a page of numbers is hard to read alone. AI DiagMe turns a lipid panel, an HbA1c or a vitamin panel into clear, plain-language explanations, so you can see where you stand and what to discuss with your doctor. It helps you understand your results; it does not diagnose dementia or replace medical advice.
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