How to lower your dementia risk as cases expected to rise by 2060

Research shows that dementia cases are going up, with a study released this week estimating that cases in the United States, for instance, will double by 2060.

The study, published in the journal Nature Medicine on Monday, found that the risk of developing dementia after age 55 is double that reported by previous studies, estimating it at 42 per cent. They said this was tied to population ageing.

Previous research has estimated that global cases of dementia will rise due to population ageing and growth including a 2022 study that estimated global cases could rise from 57.4 million cases in 2019 to nearly 153 million in 2050.

Western Europe would see an estimated 74 per cent increase in cases by 2050, central Europe would have an 82 per cent increase, and eastern Europe would see a 92 per cent increase, according to the study.

But people can take steps to reduce their risk of dementia, such as controlling high blood pressure and other bad-for-the-brain health problems, and it’s not too late to try even in middle age.

"All of our research suggests what you do in midlife really matters," said Dr Josef Coresh the study's co-author from New York University (NYU) Langone Health in the US.

Dementia isn't only Alzheimer's

Dementia is the progressive loss of memory, language, and other cognitive functions.

Alzheimer’s is the most common form, and silent brain changes that eventually 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 brewing Alzheimer's symptoms.

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

"It’s not a guarantee that someone will develop dementia," said Dr James Galvin, a University of Miami Alzheimer’s specialist. He wasn’t involved with the new study but said the findings fit with other research.

Dementia risk is different by age

Prior studies estimated about 14 per cent of men and 23 per cent of women would develop some form of dementia during their lifetime.

Coresh’s team analysed more recent data from a US study that has tracked the heart health and cognitive function of about 15,000 older adults for several decades. Importantly, they found the risk changes with the decades.

Only 4 per cent of people developed dementia between the ages of 55 and 75, what Coresh calls a key 20-year window for protecting brain health.

For people who survive common health threats until 75, the dementia risk then jumped to 20 per cent by age 85 and 42 per cent between ages 85 and 95.

Overall, the lifetime dementia risk after age 55 was 35 per cent for men and 48 per cent for women, the researchers concluded.

Women generally live longer than men, a main reason for that difference, Coresh noted. Black Americans had a slightly higher risk, 44 per cent, than white people at 41 per cent.

Ways to lower dementia risk

There are some risk factors people can't control, including age and whether you inherited a gene variant called APOE4 that raises the chances of late-in-life Alzheimer's.

But people can try to avert or at least delay health problems that contribute to later dementia.

Coresh, for example, wears a helmet when biking because repeated or severe brain injuries from crashes or falls increase the risk of later-in-life dementia.

Especially 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 blood pressure, diabetes and cholesterol.

For example, high blood pressure can impair blood flow to the brain, a risk not just for vascular dementia but also linked to some hallmarks of Alzheimer's.

Similarly, the high blood sugar of poorly controlled diabetes is linked to cognitive decline and damaging inflammation in the brain.

Stay socially and cognitively active, too, Galvin said. He urges people to try hearing aids if age brings hearing loss, which can spur social isolation.

"There are things that we have control over, and those things I think would be really, really important to build a better brain as we age," he said.