The global total of people living with dementia will rise nearly three-fold by 2050, researchers say.
Cases are projected to increase from an estimated 57.4 million in 2019 to an estimated 152.8 million in 2050, driven mainly by population growth and aging.
This "emphasizes the vital need for research focused on the discovery of disease-modifying treatments and effective low-cost interventions for the prevention or delay of dementia onset," said lead researcher Emma Nichols of the University of Washington School of Medicine.
By 2050, 16% the world's population will be people over 65. That compares with 8% in 2010, according to the U.S. National Institute on Aging.
The researchers said the largest increases in dementia are expected to occur in eastern sub-Saharan Africa, North Africa and the Middle East.
While positive trends in education access worldwide are expected to result in 6.2 million fewer dementia cases by 2050, smoking, excess weight and high blood sugar are predicted to boost cases by 6.8 million.
The projections, covering 1999 to 2019, are based on data from the Global Burden of Disease (GBD) study, a set of worldwide health trend estimates.
The findings were presented Tuesday at a meeting of the Alzheimer's Association, held in Denver and online. Research presented at meetings is typically considered preliminary until published in a peer-reviewed journal.
"Improvements in lifestyle in adults in developed countries and other places — including increasing access to education and greater attention to heart health issues — have reduced incidence in recent years, but total numbers with dementia are still going up because of the aging of the population," said Maria Carrillo, chief science officer of the Alzheimer's Association.
"In addition, obesity, diabetes and sedentary lifestyles in younger people are rising quickly, and these are risk factors for dementia," she added in a meeting news release.
Nichols said these estimates would help policymakers and decision makers better understand the expected increases in dementia and what's driving them.
Her team used the same data to estimate that Alzheimer's disease death rates rose 38% worldwide between 1990 and 2019. That study was published last year in Alzheimer's & Dementia: The Journal of the Alzheimer's Association.
Carrillo said the numbers will grow beyond 2050 without effective treatments to stop, slow or prevent Alzheimer's and all dementia. This will affect individuals, caregivers, health systems and governments.
"In addition to therapeutics, it's critical to uncover culturally tailored interventions that reduce dementia risk through lifestyle factors like education, diet and exercise," Carrillo said.