Comprehensive exposome score predicts incident dementia risk
An exposome-based model reached an AUC of 0.718 for incident dementia, outperforming demographics and APOE status alone at 0.678 over 15.3 years of follow-up.
Alzheimer's & Dementia
Researchers analyzed 499,992 UK Biobank participants aged 40 to 69 to evaluate how 193 environmental factors across five domains associate with dementia. Over a median 15.3-year follow-up, 8,881 participants developed Alzheimer’s disease and related dementias, including 4,000 with Alzheimer's disease.
An exposome-wide association study identified 76 exposures significantly linked to dementia risk after Bonferroni correction, including 45 detrimental and 31 protective factors spanning social, physical, chemical, lifestyle, and ecosystem domains. Prominent risk-enhancing features included medication count, air pollution, and unemployment, whereas physical activity and higher household income were protective. Investigators trained an XGBoost model and built an exposomic risk score, showing that participants in the highest score quartile had a higher dementia rate (hazard ratio 2.97, 95% CI: 2.59–3.41) than those in the lowest quartile.
Why it matters
Dementia risk reflects complex interactions between genetic susceptibility and cumulative lifetime environmental exposures. Quantifying the exposome provides a framework for multi-factorial risk stratification and identifies modifiable lifestyle and environmental targets to support cognitive resilience in aging.
Caveats
The study is observational and cannot establish causal mechanisms between the identified exposures and neurodegeneration. In addition, exposures were measured primarily at baseline in a predominantly White British UK Biobank cohort, requiring prospective validation across more diverse populations.
The paper
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Randall J. Ellis, Shakson Isaac, Sai Zhang, Gary W. Miller, Yi Sun, Shalini Jain, Hariom Yadav, Peng Gao,Harvard University
Alzheimer's & Dementia · 30 Sep 2026