Up to 4 in 10 people could develop dementia after age 55. How to reduce your risk?

By LAURAN NEERGAARD ​​AP Medical Editor

WASHINGTON (AP) — About one million Americans each year are expected to develop dementia by 2060, about double the current toll, researchers reported Monday.

That estimate is based on a new study that found a higher lifetime risk than previously thought: After age 55, people have up to a 4 in 10 chance of eventually developing dementia — if they live long enough.

It’s a sobering number, but there are steps people can take to reduce this risk, such as controlling high blood pressure and other brain-damaging health conditions. And it’s not too late to try, even in middle age.

“All of our research suggests that what you do in midlife really matters,” said Dr. Josef Coresh of NYU Langone Health, co-author of the study in the journal Nature Medicine.

Dementia is not just Alzheimer’s disease

Taking longer to remember a name or where you put your keys is typical with age. But dementia is not a normal part of aging: it is a progressive loss of memory, language and other cognitive functions. Simply getting older poses the greatest risk and the population is aging rapidly.

Alzheimer’s disease is the most common form, and the silent brain changes that lead to it can begin two decades before symptoms appear. Other types include vascular dementia, when heart disease or small strokes impair blood flow to the brain. Many people have mixed causes, meaning vascular problems could exacerbate emerging symptoms of Alzheimer’s disease.

Measuring risk from a certain age over the remaining potential lifespan can guide public health recommendations and medical research.

“It’s not a guarantee that someone will develop dementia,” cautioned Dr. James Galvin, an Alzheimer’s disease specialist at the University of Miami. He was not involved in the new study, but said the results were consistent with other research.

The risk of dementia differs depending on age

Previous studies estimated that about 14% of men and 23% of women will develop some form of dementia during their lifetime. Coresh’s team analyzed more recent data from a U.S. study that tracked the heart health and cognitive function of about 15,000 older people over several decades.

More importantly, they found that risk changed over decades.

Only 4% of people developed dementia between the ages of 55 and 75, which Coresh calls a key 20-year period for protecting brain health.

For people who survive common health threats to age 75, the risk of dementia then jumped: to 20% at age 85 and to 42% between ages 85 and 95.

Overall, the lifetime risk of dementia after age 55 was 35% for men and 48% for women, the researchers concluded. Women generally live longer than men, which is the main reason for this difference, Coresh noted. Black Americans had a slightly higher risk, 44%, than whites, 41%.

Yes, there are ways to reduce the risk of dementia

There are some risk factors that people cannot control, including age and whether you have inherited a genetic variant called APOE4 that increases your chances of developing Alzheimer’s disease in later life. .

But people can try to avoid or at least delay health problems that contribute to later dementia. Coresh, for example, wears a helmet when he rides a bike because repeated or severe brain damage from accidents or falls increases the risk of dementia later in life.

Particularly important: “What’s good for your heart is good for your brain,” added Miami’s Galvin. He urges people to exercise, avoid obesity and control their blood pressure, diabetes and cholesterol.

For example, high blood pressure can impair blood flow to the brain, a risk not only for vascular dementia but also linked to some features of Alzheimer’s disease. Likewise, high blood sugar due to poorly controlled diabetes is linked to cognitive decline and damaging inflammation in the brain.

Also stay socially and cognitively active, Galvin said. He urges people to try hearing aids if age causes hearing loss, which can contribute to social isolation.

“There are things that we have control over, and I think those things would be really, really important for building a better brain as we age,” he said.

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