The 14 Modifiable Risks (Lancet Commission)
45% of dementia is preventable
The Lancet Commission on Dementia Prevention, Intervention, and Care identified 14 modifiable risk factors. If every single one were eliminated globally, ~45% of dementia cases could be prevented or delayed. That's not incremental — it's nearly half the problem, gone.
Hearing loss is the biggest single one
Untreated hearing loss is the single largest modifiable risk — accounting for ~7% of preventable cases. The mechanism: auditory deprivation drives social isolation AND reduces cognitive stimulation AND may directly increase neurodegeneration. Hearing aids aren't cosmetic — they're brain protection.
The 14 modifiable risks
Tap each risk to see its mechanism and when to intervene.
This step is interactive — open the Thier app to try it.
Stack them and the number grows
The 45% figure assumes independent effects. In practice many risks overlap (obesity → diabetes → hypertension → vascular dementia). Addressing a cluster of related risks often buys more than the sum of each individually. This is why a holistic longevity programme outperforms single-factor interventions.
Hearing loss is the biggest single lever
The 2024 Lancet Commission update added two new modifiable risks (high cholesterol, vision loss) and ranked hearing loss as the single largest contributor — accounting for ~7% of dementia risk attributable to a single factor. Untreated hearing loss accelerates cognitive decline through reduced brain stimulation and social withdrawal. Hearing aids in the ACHIEVE trial cut 3-year cognitive decline by 48% in at-risk older adults. Get screened, wear aids if needed.
Key Takeaway
Dementia prevention is not mysterious. A large fraction of it comes from treating blood pressure, ApoB, hearing loss, depression, and social isolation aggressively from midlife onward. Most primary-care systems don't frame any of this as brain care. You have to.