Abstract

The last 200 years have seen a hugely successful effort by the world’s economies to change the main risk factor for dementia: the age at which we die. Unfortunately, this has been in the wrong direction and one in three of us now die suffering from dementia. The societal costs are huge. Less pessimistically, the age-specific prevalence of dementia has recently been shown to have declined in the UK from 8.3% to 6.5% of those over 65 years over the last 20 years. This substantial change, shown by the robust MRC Cognitive Function and Ageing Study, suggests that there may be risk factors which can be modified. Obvious candidates include diet, education and vascular risk factors (blood pressure, smoking, cholesterol, diabetes and exercise). Some risk factors may be more dementia-specific, averting or slowing symptom progression in prodromal disease. We all have a personal stake in knowing whether interventions which alter these putative risks will reduce our chances of dementia.