Research published in The Lancet Neurology by Miss Yu-Tzu Wu and Professor Carol Brayne (Institute for Public Health), and colleagues, reviews five recent epidemiological studies in four western European countries including the UK (the Cognitive Function and Ageing Studies, led from Cambridge), Netherland, Sweden and Spain. These five studies investigated the prevalence and incidence of dementia over time.

The results show stable or reduced dementia occurrence over the past 20 to 30 years which suggests that the number of people with dementia could be stabilising in some countries despite population ageing. The findings suggest the possibility of preventing or reducing the risk of dementia at any given age for the whole population. Improved education, living conditions, prevention and better management of chronic diseases over the last century might underlie this stable or reduced trend in dementia occurrence.

Yu-Tzu and colleagues suggest that primary prevention across the whole of life, including policies that address the determinants of health and enhance capacity (brain reserve), should receive attention at societal policy levels as well as investment in relevant research.