Experts say many cases can be prevented.
For Americans reaching middle age today, the odds of developing dementia are roughly the same as flipping a coin.
A new study from New York University (NYU) Langone Health and Johns Hopkins University suggests that nearly half of Americans who are dementia-free at age 55 will develop the condition in their lifetime—a finding that researchers say demands attention. With the annual number of new cases in the United States expected to nearly double by 2060, researchers highlight the importance of policies and individual approaches that support healthy aging.
While the projections are concerning, there’s a growing body of evidence showing that prevention is possible, Dr. Josef Coresh, lead author of the study and founding director of the Optimal Aging Institute at NYU Langone, told The Epoch Times.
Why Are Dementia Cases Rising?
Published in Nature Medicine on Monday, the new study estimates that the number of new dementia cases in the United States will rise from about 520,000 per year (2020) to 1 million by 2060.
The researchers found that over 40 percent of people who don’t have dementia at age 55 will eventually develop it.
The risk increases significantly over time. Twenty percent of people will develop dementia by age 85, with 4 percent of those developing it by 75. Another 22 percent will develop it after age 85.
Women face a higher lifetime risk due to their longer lifespans.
The increase in dementia cases is closely linked to the aging U.S. population. As people live longer, the number of those at risk naturally rises.
However, the rise in dementia cases is also influenced by a variety of factors, including lifestyle-related diseases that impair vascular health.
Conditions like diabetes, hypertension, obesity, and poor cardiovascular health are on the rise in the United States. They can accelerate the progression of dementia by damaging the brain’s blood vessels and disrupting cognitive function, noted Coresh, who is also an epidemiologist.
The study also predicted a significant increase in dementia cases among black Americans, who are expected to see their numbers triple by 2060. This increased risk is largely attributed to social and health factors, including elevated rates of hypertension and diabetes.
Additionally, genetic factors increase susceptibility. Approximately 25 percent of Americans carry the Alzheimer’s-linked APOE4 gene, which impedes the brain’s ability to clear protein buildups. While the risk of developing dementia varies based on the number of copies of the gene a person carries, the presence of the gene does not guarantee dementia.
Environmental factors also contribute to dementia risk, including exposure to a high level of air pollution and chronic stress, which can elevate cortisol levels and adversely affect brain function.
Dementia Risks Can Be Halved
“If you have higher genetic risk for dementia, you can still reduce your risk by a third with preventative strategies,” Coresh said.
- Maintaining healthy blood pressure
- Controlling diabetes
- Staying active
- Eating a balanced diet
- Avoiding smoking
“The things that are good for your heart are good for your brain,” Coresh said. Delaying or managing diabetes—especially before the age of 65—can significantly reduce dementia risk, he added.
The Lancet report attributes high low-density lipoprotein (“bad”) cholesterol in midlife (around age 40) as a factor linked to 7 percent of dementia cases.
The Importance of Hearing Aids and Staying Social
Hearing loss and social isolation also play a role in the development of dementia.
Hearing loss increases cognitive load, forcing the brain to work harder to process information in noisy environments. Coresh said to imagine you’re in a really loud restaurant or subway and trying to have a conversation. Over time, this stress can harm your brain cells.
He said that research has shown that older adults who receive hearing aids (compared to those who don’t) cut their cognitive decline rate by almost half.
Coresh stressed the value of social engagement in reducing dementia risk. “If you walk with somebody else, if you do things with other people, that’s a great way to reduce your risk,” he said. Social interaction often involves conversations, games, and activities that challenge the mind. These activities help keep the brain active and engaged, which can strengthen cognitive function and slow cognitive decline.
He also pointed out that vision problems may contribute to dementia, highlighting the importance of regular eye and hearing checkups.
Vision loss, especially in older adults, is linked to poor blood flow. Conditions like macular degeneration and glaucoma, which affect vision, are often associated with vascular health issues—particularly narrowing of blood vessels. Less blood flow to the brain or eyes makes it harder for the brain to process information and maintain clear vision, aggravating cognitive decline.
Looking Ahead
The current economic burden of dementia in the United States is significant, with total costs exceeding $600 billion annually. It is expected to surpass $1 trillion by 2050.
Future research aims to follow patients past age 85 to understand late-onset dementia more clearly. Moreover, there is a strong emphasis on developing biomarkers for early diagnosis, akin to the monitoring of cholesterol levels today.