# Dementia Risk After 90 Isn't Fixed: Sex and Genes Still Shape the Odds

*Incidence of dementia after age 90 years and association with APOE genotype, race, and sex in the USA: the LifeAfter90 prospective cohort study.*

- **Evidence Level**: Moderate
- **Publication Types**: Journal Article
- **Journal**: The lancet. Healthy longevity
- **Sample Size**: 805 adults aged 90-103, dementia-free at start
- **Authors**: Colbeth HL, Corrada MM, Mungas D, Gilsanz P, George KM, Gaied R, Kawas CH, DeCarli C, Whitmer RA
- **Published**: 2026-08-04
- **Topics**: dementia, brain health, genetics
- **DOI**: https://doi.org/10.1016/j.lanhl.2026.100882
- **Original Source**: https://pubmed.ncbi.nlm.nih.gov/42551464/

## Summary

Reaching 90 doesn't mean you've escaped dementia risk. Among 805 people aged 90 and older in California, about 17% developed dementia over roughly two years. Women had nearly twice the risk of men, and carriers of the APOE ε2 gene variant had noticeably lower risk. The famous APOE ε4 risk gene did not show a clear link at this age.

## Practical Takeaway

This study suggests brain health screening still matters well past age 90.

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_Canonical: https://longevity-germany.com/en/research/dementia-risk-after-90-isn-t-fixed-sex-and-genes-still-shape-the-odds · Part of Longevity Cities · Updated 2026-08-04_