Some 1.7 million people could be living with dementia in England and Wales by 2040 – over 40% more than previously thought, research suggests.

A new analysis published in the Lancet Public Health shows rising cases, meaning the “burden on health and social care might be considerably larger than currently forecast”.

The study, led by University College London (UCL), updates previous work suggesting dementia cases would reach 1.2 million people in 2040 despite a dip in rates for several years.

Researchers behind the new study wrote: “Dementia incidence followed a non-linear trend in England and Wales with a declining trend from 2002 to 2008 and an increased trend from 2008 to 2016.

“If the upward incidence trend continues, along with population ageing, the number of people with dementia in England and Wales is projected to increase to 1∙7 million in 2040.”

For the study, experts analysed nine sets of data from people over the age of 50 and living in private households in England between 2002 and 2019, from the English Longitudinal Study of Ageing (ELSA).

They found that the dementia incidence rate decreased by 29% between 2002 and 2008 but rose a quarter between 2008 and 2016.

Lead author Dr Yuntao Chen, from the UCL Institute of Epidemiology and Health Care, said: “It is shocking to think that the number of people living with dementia by 2040 may be up to 70% higher than if dementia incidence had continued to decline.

“Not only will this have a devastating effect on the lives of those involved but it will also put a considerably larger burden on health and social care than current forecasts predict.

“Continued monitoring of the incidence trend will be crucial in shaping social care policy.”

Although an increase in dementia cases has often been put down to an ageing population, the researchers also found that the rate of people developing dementia in older age groups is also rising.

Principal investigator Professor Eric Brunner, from the UCL Institute of Epidemiology and Health Care, said: “Our research has exposed that dementia is likely to be a more urgent policy problem than previously recognised – even if the current trend continues for just a few years.

“We have found that not only is the ageing population a major driver of the trend in England and Wales but also the number of people developing dementia within older age groups is increasing.

“We don’t know how long this pattern will continue but the UK needs to be prepared so we can ensure that everyone affected, whatever their financial circumstances, is able to access the help and support that they need.”

James White, head of national influencing at the Alzheimer’s Society, said: “Dementia is the biggest health and social care issue of our time.

With more people expected to be living with dementia in the future, healthcare decision-makers need to wake up and put steps in place to radically improve both how the condition is diagnosed and invest in capacity to do so

“(These statistics) are a stark reminder that, without action, the individual and economic devastation caused by dementia shows no sign of stopping.

“We know that one in three people born in the UK today will develop this terminal condition in their lifetime.

“With prevalence on the rise, improving diagnosis has never been more important.

“Everyone living with dementia must have access to a timely, accurate and specific diagnosis, and who you are or where you live should have no bearing on this.

“The figures also make it clear that pressure on our already struggling social care system is only going to increase.

“Quality social care can make a huge difference to people’s lives, but we know that people with dementia – who are the biggest users of social care – are struggling with a care system that’s costly, difficult to access, and too often not tailored to their needs.”

Hilary Evans, chief executive at Alzheimer’s Research UK, said the research “highlights the enormous threat dementia poses” for the public and the healthcare workforce.

“With more people expected to be living with dementia in the future, healthcare decision-makers need to wake up and put steps in place to radically improve both how the condition is diagnosed and invest in capacity to do so,” she added.

“Too many people continue to experience unacceptable delays, and waiting times frequently fall short of the government’s 67% target in many regions. This is only going to get worse unless decisive government steps are taken to confront this crisis.”

A Department of Health and Social Care spokeswoman said: “We want every person with dementia to receive high quality, compassionate care, regardless of age, gender, or background, which is why the NHS is committed to improving diagnosis rates, access to new treatments through increased funding, working together and making use of the latest technology.

“We are providing £160 million a year by 2024/25 for dementia research to accelerate the development of the latest treatments and technology and our Major Conditions Strategy recognises not only the importance of tackling this disease but will set out the standards patients should expect at all stages of dementia care.

“Our £570 million Market Sustainability and Improvement Fund (MSIF) Workforce Fund will increase adult social care capacity, improve market sustainability, and enable local authorities to make tangible improvements to adult social care services.”