More than 1.2 million people are expected to be living with dementia in England and Wales by 2040, up from almost 800,000 today, research suggests.

Researchers say the predicted rise in the prevalence of dementia is largely down to people living longer, but add that the figures also show that the risk of developing dementia for each age group is falling – a finding they say suggests that preventive strategies are having an impact.



“The growth in numbers of cases of dementia is not as large as we once anticipated,” said Sara Ahmadi-Abhari, an epidemiologist and co-author of the research from University College, London. “But, nonetheless, the growth in the number of people with dementia is substantial.”

The team note that improved forecasts for the numbers of people expected to be living with dementia in the future are important to make sure support is available. At present the costs of dementia to the UK economy are estimated to be £23bn a year.

The latest figures, published in the British Medical Journal, are based on data from the English Longitudinal Study of Ageing (Elas) – an ongoing project that began in 2002 and is designed to look at a range of factors affecting people aged 50 and over, including their health.



Among the assessments carried out, participants were asked to complete memory tasks, solve maths problems and were asked about their ability to carry out daily activities, with any diagnosis of dementia also recorded.

The international team of researchers examined data from 18,000 men and women collected between 2002 and 2013, to look at trends in the proportion of new cases of dementia and the prevalence of the condition and cardiovascular disease over time. In addition, data from the Office for National Statistics was combined with data from the Elas to help the team to explore trends in mortality from both cardiovascular disease and non-cardiovascular causes.

“Dementia and cardiovascular disease share risk factors,” said Ahmadi-Abhar. “To be able to get a better picture of the health gains [of public health interventions], we need to model them together.”



The team then fed the data into a computer-based model to predict figures for those living with dementia in England and Wales in the years to come.

The findings reveal that both the incidence and prevalence of dementia for each age group is falling, but as prevalence remains highest among the oldest, and more people are living longer, overall prevalence and the number of people living with the dementia is on the rise.

“There is very little doubt that we are going to see an increase in the actual number of people with dementia,” said Julie Williams, an associate director of the UK Dementia Research Institute at Cardiff University who was not involved in the study. But she adds there are signs of hope. “It is heartening that we see a reduction in the rate, which is likely to be due to healthy living,” she said.

Ramon Luengo-Fernandez of the Health Economics Research Centre at the University of Oxford who was not involved in the research, said that the study underscores the importance of central and local government tackling the social care crisis in older age.

“Although the pressures created by dementia to the NHS, social services and society in general – for example, impact on relatives who have to care for people with dementia in the community – might not be as bad as once feared, the study highlights that these pressures will still be considerable,” he said.

The research comes at the same time as a number of other investigations into dementia.

Among them, a small study published in the journal Neurology has found that among participants with an elevated risk of Alzheimer’s, those who reported poorer sleep quality had more biomarkers associated with the disease in their spinal fluid.



But, the authors note, it is not clear if the sleep problems are increasing the risk of developing the disease or vice versa.

Another study, published in the journal Nature, has unravelled the structure of filaments that are found tangled inside cells in the brain of those with Alzheimer’s, and are made of a protein known as tau.



By revealing the different structures of these tau filaments, researchers say they hope to be better able to understand how and why they tangle, which in turn could eventually lead to development of drugs to prevent such clumps developing.

John Hardy, professor of neuroscience at University College, London who was not involved in the research, welcomed the study. “This is a fantastic piece of work which will help us understand the pathogenesis of Alzheimer’s better,” he said. “It really is a tour de force.”

