Dementia has a multifactorial etiology including social, environmental, behavioral and neurobiological factors. The validity and status of currentlydocumented dementia risk factors are often uncertain, based on few studies, or inconsistent. We combined quantitative and qualitative information to summarize and weight the most important dementia risk factors.

Identifying the major modifiable midlife risk factors for dementia is crucial to develop effective preventive strategies and improve healthy late life cognitive functioning.

The present study is part of the FP-7 funded In-MINDD (Innovative Midlife Intervention for Dementia Deterrence) project, which aims to identify the most important modifiable risk factors for dementia.

Dementia risk factors named by international dementia experts in a Delphi study were synthesized with information from a systematic literature review. The literature research conducted in PubMed used a search strategy modified from Plassman et al. (2010). This yielded 3,127 abstracts, of which 327 were included for further scrutiny based on title and abstract. The results were pooled with those from previous reviews to arrive at the final risk inventory.

The risk factors named by experts were among the best-documented risk factors based on previous literature and our systematic review. These include depression, hypertension, physical inactivity, diabetes, obesity, hyperlipidemia, and smoking. We also identified new candidate risk factors that need further validation: coronary heart disease, renal dysfunction, stroke, and inflammation.

This study provides strong support for somatic and lifestyle factors in the etiology of dementia and flags several important targets for prevention in midlife.