Blood pressure, smoking and alcohol use, association with vascular dementia

The success of the ageing global population brings with it a growth in the number of dementia sufferers. Older adults are at highest risk of dementia and are likely to manifest both vascular and Alzheimer's pathology. Blood pressure also changes with ageing and there is evidence linking high blood pressure in midlife to an increased risk of later dementia. Data from later life is sparser. A number of intervention trials have been carried out with antihypertensives and have shown mixed results with regard to cognitive and dementia outcomes (both dementia overall and of vascular and Alzheimer's types). Meta-analyses have in general not found an association between blood pressure lowering and reduced dementia incidence, although the number of cases reported in the placebo controlled trials is invariably lower in the actively treated group. Systematic reviews and meta-analyses have also been published with regard to smoking and alcohol use and incident dementia. Despite mixed reports, overall smoking was associated with an increased risk of later dementia and alcohol with a 'U' or 'J' shaped relationship. Following the systematic reviews subsequent publications tend to report similar findings. The literature in this area suffers from differing populations, lengths of follow up and assessments of both risk factor and outcome. However, at present, maintenance of cognitive function would seem to be best served by treating cardiovascular risk factors in accordance with current guidelines, controlling blood pressure, reducing smoking and if consuming alcohol doing so in moderation. This review will concentrate on the prevention of dementia and attempt to provide an overview of the evidence relating to vascular related dementia and the potential risk factors of hypertension, alcohol use and smoking behaviour.