Brain agingHumans

Statins cut Alzheimer's risk but raise other dementia risks

A Mendelian randomization analysis found total cholesterol mediated 93.91% of statins' effect on overall dementia and 84.37% on dementia in Alzheimer's disease.

Figure 1. Study overview. Step 1 illustrates the causal relationships between statin medication and dementias.Study overview. Step 1 illustrates the causal relationships between statin medication and dementias.He et al.

Journal of Alzheimer's Disease Reports4 Oct 2026, 07:19 BST

In humans, researchers analyzed genome-wide association study summary data using Mendelian randomization to evaluate causal links between statins, plasma lipids, and various dementia subtypes. Inverse variance-weighted analyses indicated that statin medication significantly reduced the risk of Alzheimer's disease. In contrast, statin use was associated with an increased risk of dementia in Alzheimer's disease and dementia with Lewy body. Elevated total cholesterol increased the risks of dementia, dementia in Alzheimer's disease, and dementia with Lewy body, whereas higher low-density lipoprotein cholesterol decreased Alzheimer's risk. Total cholesterol mediated 93.91% of the effect of statins on dementia, 84.37% on dementia in Alzheimer's disease, and 61.94% on dementia with Lewy body. Genetically mimicked statin effects did not display a mediating role.

Why it matters

Statins are widely prescribed to older populations, yet their impact on brain aging remains contentious. Demonstrating that statins and cholesterol pathways exert divergent, subtype-specific effects could help clarify how lipid metabolism influences neurodegenerative disease in late life.

Caveats

The study relies on summary-level observational genetic data rather than randomized clinical trials. Furthermore, genetically mimicked statin effects did not show the mediating role observed with reported statin use.