Several vascular and lifestyle related factors have been suggested to influence the development of dementia and Alzheimer's disease (AD), creating new prevention opportunities. This paper discusses current epidemiological evidence and new findings from the Finnish population based CAIDE study linking some of these factors to dementia/AD. Such findings provide an optimistic outlook especially for persons with genetic susceptibility; it may be possible to reduce the risk or postpone the onset of dementia by adopting healthy lifestyle options. The interplay of genes and environment in the aetiology of AD needs to be further investigated as well as the role of lifestyle and pharmacological interventions for the prevention of dementia.