What lifestyle factors protect against dementia?
The short answer
The 2024 Lancet Commission on dementia prevention identified 14 modifiable risk factors that together account for approximately 45% of dementia cases worldwide. Addressing these could prevent or delay nearly half of all dementia cases globally.
The data
| Risk factor | Life stage | % of dementia attributable |
|---|---|---|
| Low education | Early life | 5% |
| Hearing loss | Midlife | 7% |
| Hypertension | Midlife | 2% |
| Obesity | Midlife | 1% |
| Physical inactivity | Midlife | 2% |
| Diabetes | Later life | 2% |
| Smoking | Later life | 5% |
| Depression | Later life | 3% |
| Social isolation | Later life | 5% |
| Air pollution | Later life | 3% |
| Traumatic brain injury | All ages | 3% |
What it means for you
The single most actionable factor is physical activity — it addresses multiple mechanisms simultaneously (vascular health, neurogenesis, BDNF, depression, sleep quality). Track your processing speed with the Reaction Time test annually as a longitudinal check on brain health.
Medical disclaimer
This content is for educational purposes only and is not medical advice. Scores from online tests are not diagnostic - if you are concerned about symptoms such as memory loss, attention problems, or cognitive decline, consult a qualified clinician.
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Quick Answer
The Lancet Commission (2024) identifies 14 modifiable risk factors that together account for ~45% of dementia cases. The most impactful: physical inactivity, untreated hypertension, hearing loss, heavy alcohol use, smoking, social isolation, and poor sleep.
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