Press Release

Health and wealth does not affect incidence of dementia in England and Wales

23 August 2005

Results from the Medical Research Council (MRC) Cognitive Function and Ageing Study show that improved health and mortality are not likely to guard against the risk of developing dementia, according to a paper published today in Public Library of Science Medicine by Dr Fiona Matthews of the MRC Biostatistics Unit in Cambridge and Professor Carol Brayne from the University of Cambridge.

The Medical Research Council Cognitive Function and Ageing study (MRC CFAS) interviewed 13,004 individuals aged 65 years and above using identical methodology from five diverse locations across England and Wales.  The multi-centre study measures robustly, for the first time, any variation of the incidence of dementia across five sites within England and Wales and produces overall estimates by age and sex.  It concludes that there is no convincing evidence of variation in dementia rates across England and Wales.

Dementia is a change in mental function sufficiently severe to interfere with day-to-day living and affects around 550,000 people in the UK.  The incidence of dementia is known to vary between nations, but clear variation has not been shown in western countries.  This is the first study of its kind within a single country. 

Incidence rates for dementia rise with age both in men and women.  In individuals aged 75-79 years, 1 in 70 people will develop dementia in any given year.  In those aged 85 years and above, where the population is set to increase the most over the next decade, this increases to 1 in 15.  The study estimates that approximately 163,000 new cases of dementia occur in England and Wales each year.

Dr Matthews, Senior Research Scientist at the MRC Biostatistics Unit said, "One quarter of people aged 85 and over suffer from dementia.  This new research will help those planning services for people with dementia to estimate requirements now and in the future.  However, more research is needed to find out if the incidence of dementia in the UK is rising or falling"

Professor Brayne, Professor of Public Health Medicine at the Department of Public Health and Primary Care, University of Cambridge, said, "Unlike with many chronic diseases, the rates of new development of dementia across England and Wales do not seem to be influenced by factors such as health and overall mortality.  This could be because the moderate lifestyle differences and variation in mortality across England and Wales are not sufficiently great to influence the incidence of dementia, whereas in many parts of the world the differences in incidence of dementia between countries are sufficiently large to be easily detectable."