While the UK Biobank's cohort contains a mixture of prevalent conditions, including dementia and AD, it is important to note that ICD‐10‐CM codes might not always be accurate, particularly for these types of diagnoses. Furthermore, given the observational nature of the UK Biobank data, our results showing that statin use was associated with lower risk of cognitive impairment in AD among APOE ε4 carriers, needs to be further validated by a randomized clinical trial. This evidence concerns the gene APOE and dementia.