All factors

Smoking

Current smoking raises dementia risk by about 27 percent and Alzheimer's risk by about 80 percent. Quitting at any age reduces risk.

Population risk1.4%
Evidence gradeCommission report

A standing panel of researchers reviews every study on a factor and weighs the evidence together. The 2024 Lancet Commission stands behind most of the numbers on this page.

Why it matters

Smoking damages blood vessels throughout the body, including the brain's small vessels. Quitting reverses much of the excess risk within a few years.

What to ask at the checkup

Ask about smoking cessation support and whether nicotine replacement or medication would help

Screening: Self-reported smoking status

Sources

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

Smoking as a Risk Factor for Dementia and Cognitive Decline: A Meta-Analysis of Prospective Studies

Anstey KJ, von Sanden C, Salim A et al.. American Journal of Epidemiology, 2007.

Current smokers had about a quarter more dementia risk, and nearly double the Alzheimer's risk, compared with people who never smoked.

DOIAbstract only

Routines for this factor

Swap the after-dinner cigarette for the walk

When the urge to smoke comes after dinner, walk for ten minutes instead.

10 min, difficulty 3/3

This is research information, not medical advice. Nothing here replaces your parent's doctor.