A hypothesis-free, triangulated study of 497,856 UK adults found that among 68 modifiable factors significantly associated with ischemic stroke, 18 demonstrated robust causality, and a one-third reduction in modifiable risk factor exposure levels would prevent 68.19% of ischemic strokes, comparable to the 72.21% prevention achieved by total eradication.
Key Findings
Results
Among 323 modifiable factors examined across seven domains, 68 were significantly associated with ischemic stroke onset in the exposome-wide association scan.
497,856 IS-free UK adults were enrolled during 2006-2010 from the UK Biobank
10,593 participants experienced ischemic stroke over a median follow-up of 14.53 years
The 323 modifiable factors spanned seven domains: early life, health and medical history, lifestyle, local environment, physical measures, psychosocial factors, and sociodemographics
Exposome-wide association scan methodology was used to identify associations in a hypothesis-free manner
Results
Of the 68 modifiable factors significantly associated with ischemic stroke, 18 demonstrated robust causality via bidirectional two-sample Mendelian randomization.
A bidirectional two-sample Mendelian randomization study was used to assess causality
The triangulation of observational and genetic approaches was used to confirm causal relationships
The remaining factors showed association but did not meet criteria for robust causality in the MR analysis
Findings were consistent across populations stratified by age, sex, and polygenic risk score-based genetic risk
Results
Eradicating all modifiable risk factors would prevent 72.21% of ischemic stroke cases.
Weighted population attributable fraction was estimated by partially eliminating exposures
The estimate for total eradication was 72.21% (95% CI 69.37%–74.83%)
This represents the theoretical maximum preventable fraction under complete elimination of all modifiable risk factors
Findings were consistent across subgroups stratified by age, sex, and genetic risk
Results
A one-third reduction in exposure levels of modifiable risk factors would prevent 68.19% of ischemic strokes, a preventive impact comparable to total eradication.
The estimate for a one-third reduction in exposure levels was 68.19% (95% CI 64.22%–71.81%)
This compares to 72.21% (95% CI 69.37%–74.83%) prevention from total eradication
The difference between partial reduction and total eradication was relatively small, supporting efficient public health strategies
The authors interpreted this as supporting "the potential for efficient public health strategies"
Results
Worsening risk profiles in each of the seven modifiable factor domains independently increased ischemic stroke risk after controlling for overlapping hazards.
Multivariable Cox models were used to assess the joint impact of exposures across domains
The seven domains examined were: early life, health and medical history, lifestyle, local environment, physical measures, psychosocial factors, and sociodemographics
Each domain contributed independently to IS risk, suggesting multi-domain intervention strategies are warranted
Overlapping hazards among exposures were controlled for in the analysis
Results
The associations between modifiable factors and ischemic stroke were consistent across subgroups defined by age, sex, and genetic risk level.
Subgroup analyses were stratified by age, sex, and polygenic risk score-based genetic risk
Consistency across genetic risk strata suggests modifiable factors are relevant regardless of inherited predisposition
Results support the generalizability of the findings within the UK Biobank population
The polygenic risk score was used as a measure of genetic susceptibility to ischemic stroke
What This Means
This research suggests that a large majority of ischemic strokes — the most common type of stroke — could potentially be prevented by addressing modifiable risk factors. Using data from nearly 500,000 adults in the UK followed for about 15 years, researchers systematically scanned 323 lifestyle, environmental, social, and health-related factors to identify which ones were linked to stroke risk. They found 68 factors with significant associations and used genetic analysis (Mendelian randomization) to confirm that 18 of these likely have a true causal relationship with stroke, rather than just being correlated.
One of the most striking findings is that while completely eliminating all modifiable risk factors could theoretically prevent about 72% of ischemic strokes, reducing those risk factors by just one-third would prevent nearly 68% — almost as much. This suggests that very large public health gains could be achieved without requiring perfect or complete risk elimination, which is rarely achievable in practice. Risk factors spanned multiple life domains including lifestyle habits, physical health measures, the local environment, and socioeconomic factors, and each domain independently contributed to stroke risk.
This research matters because it takes an unusually broad, systematic, and unbiased approach to mapping stroke risk — rather than testing one factor at a time based on prior assumptions. The finding that moderate, realistic reductions in risk exposure could achieve nearly the same benefit as total eradication has practical implications for designing public health programs aimed at stroke prevention across entire populations, including people with varying levels of genetic risk.
Zheng M, Xu Q, Xia X, Gao M, Li J, Huang X, et al.. (2026). Mapping the modifiable exposome for ischemic stroke: association, causality, and preventive potential.. Atherosclerosis. https://doi.org/10.1016/j.atherosclerosis.2026.120693