
Scientists at Johns Hopkins have estimated the lifetime risk of dementia to be 42% after age 55, highlighting higher risks in women, black adults and those with the APOE ε4 gene. They projected that new cases of dementia in the U.S. will increase from 514,000 in 2020 to 1 million by 2060, with the highest growth among black adults. Understanding the lifetime risk of dementia can inform public health planning and improve patient engagement in prevention.
Dementia is a general term used to describe a range of conditions that affect the brain, leading to progressive loss of cognitive function. These can include memory loss, difficulty thinking, language problems and changes in behavior.
The most common types of dementia include Alzheimer’s disease, vascular dementia, dementia with Lewy bodies and frontotemporal dementia. Each type has distinct causes and symptoms, but all result in mental deterioration that interferes with daily activities.
Recently, scientists at the Johns Hopkins Bloomberg School of Public Health conducted a study to better understand the risk of developing dementia over the lifetime, particularly after age 55.

Using data from a prospective cohort study involving 15,043 participants, they looked at how factors such as race, gender and genetic predisposition influence the risk of dementia.
About 26.9% of the participants were black, 55.1% were women and 30.8% carried at least one allele of apolipoprotein E4 (APOE ε4), a gene associated with an increased risk of Alzheimer's.
The researchers calculated that the risk of a person developing dementia after age 55 is approximately 42%. This risk is not uniform across populations; for example, women, black adults and people with the APOE ε4 gene face higher risks, which can range from 45% to 60%.
This means that these populations are significantly more likely to develop dementia over the course of their lives.

To understand the future impact of dementia, the researchers applied their estimates to U.S. population projections from 2020 to 2060.
They predicted that the number of new cases of dementia per year will increase from about 514,000 in 2020 to about 1 million in 2060. The steepest increase was seen among Black adults, indicating a growing inequality in the incidence of dementia.
These findings underscore the importance of public health policies focused on promoting healthy aging, especially among more vulnerable populations.
Strategies to reduce dementia risk could include health education programs, initiatives to control risk factors such as hypertension and diabetes, and policies aimed at reducing racial and socioeconomic disparities in access to quality health care.
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Lifetime risk and projected burden of dementia
Michael Fang, Jiaqi Hu, Jordan Weiss, David S. Knopman, Marilyn Albert, B. Gwen Windham, Keenan A. Walker, A. Richey Sharrett, Rebecca F. Gottesman, Pamela L. Lutsey, Thomas Mosley, Elizabeth Selvin & Josef Coresh
Nature Medicine, Brief Communication, Published: 13 January 2025
Abstract:
Understanding the lifetime risk of dementia can inform public health planning and improve patient engagement in prevention. Using data from a community-based, prospective cohort study (n = 15,043; 26.9% Black race, 55.1% women and 30.8% with at least one apolipoprotein E4 (APOE ε4) allele), we estimated the lifetime risk of dementia (from age 55 years to 95 years), with mortality treated as a competing event. We applied lifetime risk estimates to US Census projections to evaluate the annual number of incident dementia cases from 2020 to 2060. The lifetime risk of dementia after age 55 years was 42% (95% confidence interval: 41–43). Rates were substantially higher in women, Black adults and APOE ε4 carriers, with lifetime risks ranging from approximately 45% to 60% in these populations. The number of US adults who will develop dementia each year was projected to increase from approximately 514,000 in 2020 to approximately 1 million in 2060. The relative growth in new dementia cases was especially pronounced for Black adults. These results highlight the urgent need for policies that enhance healthy aging, with a focus on health equity.
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