The number of people with dementia forecast to triple by 2050

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TORONTO — The number of people with dementia is forecast to triple to an estimated 152 million worldwide by 2050, according to new data.

To make this prediction, researchers with the Institute for Health Metrics and Evaluation at the University of Washington School of Medicine analyzed data from 1999 to 2019 from the Global Burden of Disease study, which is a comprehensive set of health trends estimates worldwide. They also incorporated information on trends in dementia risk factors into the study.

They found that global dementia cases would increase from an estimated 57 million in 2019 to 152 million in 2050 with the highest increase in prevalence projected to be in eastern sub-Saharan Africa, North Africa, and the Middle East.

According to their analysis, the projected increases could largely be attributed to population growth and aging, although they said the relative importance of these two factors varied by world region.

In terms of aging, the U.S. National Institute on Aging estimates that people over the age of 65 will make up 16 per cent of the world’s population by 2050 – up from eight per cent in 2010.

Interestingly, the team found that while positive trends in access to education around the world should decrease dementia prevalence by 6.2 million cases; anticipated trends in smoking, high body mass index (BMI), and high blood sugar are expected to counter that and increase the prevalence by 6.8 million cases.

Taken together, the researchers said, these opposing trends come close to “balancing each other out.”

“These estimates will allow policymakers and decision makers to better understand the expected increases in the number of individuals with dementia as well as the drivers of these increases in a given geographical setting,” Emma Nichols, a researcher with the Institute for Health Metrics and Evaluation at the University of Washington School of Medicine, said in a release.

She added that the large anticipated increase in the number of individuals with dementia should emphasize the “vital need” for research on disease-modifying treatments and effective low-cost interventions for the prevention or delay of dementia.

Using the same data set, Nichols and her team were also able to estimate that Alzheimer’s mortality rates increased by 38 per cent between 1990 and 2019.

“Without effective treatments to stop, slow or prevent Alzheimer’s and all dementia, this number will grow beyond 2050 and continue to impact individuals, caregivers, health systems and governments globally,” Maria C. Carrillo, the chief science officer for the Alzheimer's Association, said in a release.

“In addition to therapeutics, it's critical to uncover culturally-tailored interventions that reduce dementia risk through lifestyle factors like education, diet and exercise.”

Nichols and her team presented their findings at the Alzheimer’s Association International Conference (AAIC) 2021 in Denver on Tuesday.