The number of people living with dementia around the world is set to almost triple to an estimated 152 million by 2050, researchers have predicted.

The highest rises in cases are likely to be in sub-Saharan Africa, North Africa and the Middle East, with the increase driven largely by an ageing and expanding population, scientists said.

The research from the University of Washington School of Medicine was presented at the 2021 Alzheimer’s Association International Conference (AAIC) in Colorado on Tuesday.

Researchers estimated global dementia prevalence from 1990 to 2019 and used information about trends in risk factors for dementia to make their forecasts, finding that cases would increase from an estimated 57.4 million globally in 2019 to an estimated 152.8 million cases in 2050.

They estimated that globally there would be an increase of 6.8 million dementia cases between 2019 and 2050 specifically due to things such as smoking and high body mass index (BMI), but that there could be a reduction of 6.2 million cases with improved education, almost balancing the rise out.

Separately researchers from Maastricht University in the Netherlands estimated that every year there are around 10 new cases of young-onset dementia – where people develop dementia symptoms under the age of 65 – per 100,000 people.

This suggests that around 350,000 people worldwide develop young-onset dementia annually, with incidence rates for men and women being similar, the scientists said in research presented at the same conference.

These striking figures lay bare the shocking scale of dementia on a global scale

Alzheimer’s Research UK said predictions from 2014 estimated that one million people here will have dementia by 2025, doubling to two million by 2050.

The charity said some UK-focussed research had pointed to a potential drop in the proportion of people living with dementia in any given age group, possibly due to improved levels of education and less smoking.

Hilary Evans, chief executive of the organisation, said: “Dementia is our greatest long-term medical challenge. These striking figures (from the latest US research) lay bare the shocking scale of dementia on a global scale.

“To have 57 million people already living with this devastating condition is 57 million too many, but with that number set to almost triple we need to see concerted global action now, to transform the prospects for the next generation.”

She encouraged people to make “positive lifestyle changes” to “help tip the scales in our favour” when it comes to the chances of developing the condition.

She said: “There is robust evidence that what’s good for the heart is also good for the brain. Not smoking, only drinking within the recommended limits, staying mentally and physically active, eating a balanced diet, and keeping blood pressure and cholesterol levels in check can all help to keep our brains healthy as we age.”

It is “vital” that the Government “meets the urgent need for investment across every stage of the process” in the dementia research sector, she added.