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Journal ArticleThe lancet. Healthy longevity·Aug 2026

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

Key Insight

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


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.

Conflict of Interest Disclosure: Several authors report NIH grants, plus consulting fees and industry-linked research funding.

Disclaimer: Research summaries are provided for informational purposes only and do not constitute medical advice. Always consult a qualified healthcare professional before making changes to your health routine.