All factors

Air pollution

Long-term exposure to fine particulate matter (PM2.5) increases dementia risk, even at levels common in US cities.

Population risk0.7%
Evidence gradecohort

Why it matters

Pollution particles enter the brain through the nose and blood, causing inflammation. HEPA filters and avoiding outdoor exercise on high-pollution days reduce exposure.

What to ask at the checkup

Ask whether air quality is a concern and what steps might reduce exposure

Screening: Local air quality index review

Sources

Dementia prevention, intervention, and care: 2024 report of the Lancet Commission

Livingston G, Huntley J, Liu KY et al.. The Lancet, 2024.

Fourteen things people can change account for nearly half of dementia cases at the population level.

Long-term exposure to air pollution and risk of dementia

Younan D, Wang X, Casanova R et al.. Annals of Neurology, 2020.

Breathing polluted air over years was linked to more dementia, even at levels common in US cities.

Routines for this factor

Run the air purifier today

Turn on the HEPA air purifier in the room where most time is spent.

2 min, difficulty 1/3

Exercise indoors on high-pollution days

Check the air quality index and move exercise indoors if it is above 100.

10 min, difficulty 1/3