New estimates suggest dementia cases are set to rise – are they reliable?

Two women sit at a table, looking at a health information leaflet.

By Lorik Zhubi | Friday 27 October 2023

Reliable statistics about how many people in the UK have dementia, and how this changes over time, are difficult to come by.

Compared to other common conditions, routine collection of dementia data is poor. Rather than official statistics, we have to rely on estimates published by teams of academics who study this topic, or on commissioned reports like our recent report on the economic benefits of investing in dementia research.

According to the best of these estimates, nearly a million people are living with dementia in the UK today. And other academics have analysed the data and projected that, as the UK population ages, this number could rise to 1.2 million people by 2040.

However, new evidence that emerged this week, from a UCL study published in The Lancet Public Health, suggests a much more worrying outlook: as many as 1.7 million people in England and Wales could be living with dementia by 2040.

That’s a 42% increase from previous estimates.

Should we be worried?

The importance of knowing the number of those living with dementia

It’s crucial to understand how the number of people with dementia is changing over time. Strong and credible estimates are essential in helping healthcare decision-makers ensure that services are equipped to meet the needs and demands of those affected by the condition.

At the same time, this knowledge creates urgency for action, as dementia has a devastating impact – not just on those affected and their loved ones, but also on our society and economy. Crunching the numbers, previous estimates suggested that the societal costs of dementia care in the UK are expected to nearly double, from £25bn today to around £47bn by 2050.

Analysing trends in dementia rates can also provide valuable insights to researchers about the factors that could be behind such changes, such as social factors. Knowing what risk factors are at play could help improve vital dementia prevention strategies, including information to the public about reducing their risk.

What we already knew

Until now, it’s been estimated that the number of people living with dementia in England and Wales would reach 1.2 million by 2040, driven primarily by the fact that the average age of the UK population is increasing.

But – perhaps paradoxically – these previous analyses have also suggested that percentage of older people who develop dementia has been falling – due to things like improving heart health leading to better brain health.

In other words, although overall numbers have been increasing (as there are more older people) the proportion of older people who have been develop dementia appeared to be going down – by about 2.7% a year. This means the projected increase was lower than it could have been. Which brings us to today’s study.

What this new study adds to our understanding

The new research from UCL found something worrying. The researchers looked at dementia data between 2002 and 2019 and found that, while the number of people living with dementia decreased by almost 29% between 2002 and 2008, it then started increasing again from 2008 onwards – by more than 25% between 2008 and 2016. And it’s this that’s led them to project a greater increase in future.

Possible explanations for this swing in dementia rates are the worsening of risk factors in disadvantaged communities, and improved survival from other chronic conditions like stroke.

The researchers looked at this pattern across different subgroups in terms of age, sex, and educational background. Interestingly, the researchers found that, among those who’d left school earlier, there was a slower drop in the dementia rate between 2002 and 2008, and a faster increase from 2008 onwards. This suggests that risk factors linked to social deprivation are behind the changes.

Based on their analysis, researchers calculate that if the 2.8% yearly increase in the rate of dementia observed from 2008 continues, it will translate into more than 1.7 million people living with dementia in England and Wales by 2040.

It’s important to note that these are estimates, and come with caveats. The researchers drew on data from between 2002 and 2019 from a large ongoing study called the English Longitudinal Study of Ageing (ELSA), which involves people over the age of 50 living in private households in England. The way dementia cases were identified in this study isn’t the same as the official diagnostic criteria – so it’s open to question whether their findings represent ‘true’ numbers.

Nevertheless, they’re cause for concern. It’s clear that dementia cases are set to rise – the question is simply by how much – and that should serve as a wake-up call for decision-makers.

What this means

If nothing changes, it’s clear that dementia will continue to place a growing strain on individuals, our NHS and our economy. We believe there is a substantial opportunity to change this outlook, but this can only happen if political parties commit to sustained, bold and ambitious action at the forthcoming general election.

Funding and political leadership will be vital to transform the way dementia is prevented, diagnosed and treated, and ultimately find a cure. As we set out in our latest report, this must include:


  1. A strategy for the prevention of ill health, that aims to reduce dementia risk addressing health, lifestyle, and socioeconomic factors that influence our brain health. For example, exposure to air pollution, and unmanaged hearing loss. This strategy must pay special attention to health inequalities – something underlined by today’s findings.


  1. Increased investment in the diagnostic pathway, including infrastructure, equipment, and workforce training. This is essential for early and accurate dementia diagnoses, ensuring timely access to life-changing treatments as and when they arrive.


  1. Sustained investment in dementia research. With over 180 drugs in clinical trials globally, we are now on the cusp of pioneering a new generation of dementia treatments. While continuing this work, we must now increase the UK’s capacity to deliver world class dementia drug trials, ensuring UK families are among the first to benefit from potential life changing treatments and positioning the UK as a priority location for global life sciences investment.


Decades of hard work have brought us to a tipping point – particularly with the first new Alzheimer’s drugs in over 20 years finally on the horizon. Revolutionary new diagnostics showing real promise, with blood tests for Alzheimer’s now poised to enter the clinic. So, while the findings of today’s new study are concerning, there is hope and optimism on the horizon too. Now we must keep up this momentum if we are to free individuals and society from the fear, harm and heartbreak of dementia.

For more information on this, read our report.

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About the author

Lorik Zhubi

Policy Communications Officer