January 07, 2022
3 min read
DuFouil, Nichols and Schwarzinger report no relevant financial disclosures. Please see the study for all other authors’ relevant financial disclosures.
The number of people with dementia worldwide could increase 166%, from about 57.4 million people in 2019 to 152.8 million people in 2050, data from the Global Burden of Diseases, Injuries and Risk Factors Study showed.
Overall, researchers predicted that the smallest percentage changes in the number of dementia cases will likely take place in the high-income Asia Pacific region and western Europe (53% and 74%, respectively), while the largest percentage changes will occur in eastern sub-Saharan Africa and North Africa and the Middle East (357% and 367%, respectively).
The United States could see a 100% rise in dementia cases, increasing from about 5.3 million cases in 2019 to approximately 10.5 million cases in 2050, according to the report. Three years ago, the Alzheimer’s Association estimated that unless there is a “medical breakthrough to prevent, slow, or cure Alzheimer’s disease,” there would be about 13.8 million cases of Alzheimer’s dementia in the United States in 2050.
The new report also estimated that women will continue to account for the majority of dementia cases worldwide. In 2019, women outnumbered men with dementia by 100 to 69. In 2050, researchers predict that women will outnumber men by 100 to 67.
The new projections were based on the prevalence of dementia attributable to BMI, high fasting plasma glucose and smoking status from 2019 to 2050 in 195 countries. The data were obtained through a PubMed search that was conducted on Oct. 23, 2020, several months before the FDA approved Aduhelm (aducanumab, Biogen/Eisai), the first new treatment to be approved for Alzheimer’s disease since 2003.
The findings, which were published in The Lancet Public Health, provide “improved forecasts for dementia on a global scale as well as the country level, giving policy makers and public health experts new insights to understand the drivers of these increases, based on the best available data,” Emma Nichols, MPH, a researcher at the Institute for Health Metrics and Evaluation at the University of Washington, said in a press release.
“We need to focus more on prevention and control of risk factors before they result in dementia,” added Nichols, who is also one of the Global Burden of Disease of 2019 Dementia Forecasting Collaborators. “Even modest advances in preventing dementia or delaying its progression would pay remarkable dividends.”
According to the press release, experts predict that improving access to education could result in 6 million fewer cases of dementia worldwide by 2050. However, this reduction could be offset by an estimated 7 million additional cases of dementia “linked to projected rates of obesity, high blood sugar and smoking,” the release said.
Nichols encouraged interventions that increase the availability of healthier diets, greater amounts of exercise and programs that lead to smoking cessation, as well as more efforts to educate individuals about dementia.
In a related editorial, Michaël Schwarzinger, PhD, a member of the department of methodology and innovation in prevention at Bordeaux University Hospital in France, and Carole Dufouil, PhD, an epidemiologist at Bordeaux Population Health in France, said that Nichols and colleagues “provide somehow apocalyptic projections that do not factor in advisable changes in lifestyle over the lifetime.” They also noted that the estimates are based on research “with many methodological challenges and potential biases.”
“It is unclear how meta-analyses done in silos in [Global Burden of Disease] 2019 could provide sufficient evidence to select independent risk factors or conditions that are interrelated over an individual’s lifetime,” the pair wrote.
For example, “the three selected [Global Burden of Disease] risk factors of dementia (including smoking) had much weaker associations than those reported in fully adjusted models that included alcohol use disorders,” they wrote.
Schwarzinger and Dufouil encouraged “a public health approach towards dementia to better inform the people and decision-makers about the appropriate means to delay or avoid these dire projections.”
The 2018 Alzheimer’s Disease Facts and Figures Report. https://www.alz.org/media/homeoffice/facts%20and%20figures/facts-and-figures.pdf. Accessed Jan. 6, 2022.
The Lancet Public Health: Global dementia cases set to triple by 2050 unless countries address risk factors. https://www.eurekalert.org/news-releases/939299. Accessed Jan. 6, 2022. Published Jan. 6, 2022.