U.S. Dementia Cases Are Poised to Rise to One Million Each Year by 2060, According to New Projections

As the American population ages, a new study finds the average lifetime risk of dementia for adults over 55 is around 42 percent—a higher rate than previously thought

Close-up shot of two elderly hands holding each other
Alzheimer's disease is the most common form of dementia. Robert Alexander / Getty Images

By 2060, roughly one million Americans may develop dementia each year—around double the current rate—according to a new study published Monday in the journal Nature Medicine.

Researchers found adults over the age of 55 have a 42 percent average risk of developing dementia within their lifetime, which is much higher than previously thought. Past studies have put the risk at up to 14 percent for men and up to 23 percent for women.

“I knew the total lifetime risk would be higher than previous 20-year-old estimates,” says study senior author Josef Coresh, an epidemiologist at the NYU Grossman School of Medicine, to Scientific American’s Jocelyn Solis-Moreira. “But I didn’t expect that it would land at 42 percent.”

Dementia is an umbrella term for a variety of neurological conditions that hamper cognitive functioning and memory. Alzheimer’s disease is the most prevalent form of dementia, accounting for 60 to 80 percent of dementia cases in the United States. An estimated 6.7 million Americans ages 65 and older have Alzheimer’s disease.

The increased risk is largely due to the aging American population—and in the coming years, Baby Boomers will reach older age. By 2040, for instance, all members of that generation will be at least 75 years old, and the risk of developing dementia rises with age.

Even if the actual rate of dementia cases ends up being lower than the new prediction, “we’re still going to have a big increase in the number of people and the family and societal burden of dementia because of just the growth in the number of older people, both in the United States and around the world,” says Kenneth Langa, an epidemiologist at the University of Michigan who was not involved in the study, to the New York Times’ Pam Belluck.

In addition to the aging population, researchers say the higher dementia risk can be partially explained by the study’s inclusion of diverse participants. Past research on dementia has focused primarily on white participants, whereas the new study also included Black Americans.

The study finds that Black Americans have a greater overall risk of developing dementia within their lifetime, though researchers haven’t fully figured out why. Black participants were also more likely than white participants to develop dementia at a younger age.

The number of Black Americans suffering from dementia is expected to triple by 2060, in part because the proportion of that population living to old age is growing faster than among white adults, per the New York Times. The team expects the number of white Americans suffering from dementia to nearly double by 2060.

“Racial disparities in dementia may reflect the cumulative effects of structural racism and inequality throughout the life course,” the researchers write in the paper. “For instance, poor access to education and nutrition may contribute to earlier differences in cognitive reserve, and socioeconomic disparities and limited access to care may lead to a higher burden of vascular risk factors at midlife.”

Women also have a higher overall lifetime dementia risk than men: The study finds a 48 percent risk for women, compared to 35 percent for men. That’s largely because women tend to live longer, but researchers are investigating whether hormonal or genetic factors might also be at play.

To conduct the research, scientists analyzed three decades of data from more than 15,000 people who had enrolled in a separate, long-term health study. They looked at participants between the ages of 45 and 64 who did not have dementia when they enrolled. Around 27 percent of participants identified as Black, and more than half of the participants were women.

Even though the new numbers may seem daunting, “less than half of people who make it to age 95 will have dementia,” says Andrea Bozoki, a neurologist at the University of North Carolina School of Medicine who was not involved with the new research, to NBC News’ Kaitlin Sullivan and Jessica Herzberg.

“Dementia is not an inevitable part of aging, no matter how old you are,” Bozoki adds.

Some factors that contribute to dementia risk are out of an individual’s control, such as whether they inherit a genetic variant known as APOE4, which has been found to increase the risk of Alzheimer’s disease. The new study found that individuals with two copies of the APOE4 variant had a 59 percent lifetime risk of dementia, while participants with one copy of APOE4 had a 48 percent lifetime risk. Those without the variant had a 39 percent lifetime risk of dementia. 

Still, other risk factors for cognitive decline are more manageable. Doctors recommend wearing helmets to avoid head injuries, staying socially and cognitively engaged, eating a healthy diet, getting high-quality sleep and taking steps to control vascular conditions like high blood pressure and diabetes.

“All of the things that we know are good for health in general are good for preventing dementia,” says Christine E. Kistler, a geriatric medicine expert at the University of Pittsburgh who was not involved with the new research, to the Washington Post’s Marlene Cimons. “Quitting smoking at any age is good for you. Starting to exercise at any age is good for you. We need to keep our brains working and that helps keep our brains healthy.”

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