Researchers reported on Monday that by 2060, approximately one million Americans are expected to develop dementia each year, which is roughly double the current number. This estimate comes from a new study that found a higher lifetime risk of dementia than previously believed. Specifically, after the age of 55, individuals have up to a 40% chance of eventually developing dementia, assuming they live long enough. While these statistics are concerning, there are steps that people can take to lower their risk, such as managing high blood pressure and addressing other health issues that can negatively impact brain health.
It’s important to note that it’s not too late to make changes to reduce this risk, even for those in middle age. “All of our research suggests what you do in midlife really matters,” said Dr. Josef Coresh of NYU Langone Health, who co-authored the study in the journal Nature Medicine.
Dementia isn’t only Alzheimer’s
It is common for older adults to take longer to remember names or locate their keys. However, dementia is not a normal part of ageing; rather, it is a progressive decline in memory, language, and other cognitive abilities. Aging is the most significant risk factor for dementia, and as the population continues to age rapidly, the prevalence of this condition increases. Alzheimer’s disease is the most common form of dementia, and changes in the brain that lead to Alzheimer’s can start occurring up to 20 years before symptoms manifest. Another type of dementia is vascular dementia, which occurs when heart disease or small strokes disrupt blood flow to the brain. It is important to note that many individuals may experience mixed types of dementia, where vascular issues may worsen the symptoms of Alzheimer’s.
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,” cautioned 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% of men and 23% of women would develop some form of dementia during their lifetime. Coresh’s team analyzed more recent data from a U.S. 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% of people develop dementia between the ages of 55 and 75, which researchers like Coresh identify as a crucial 20-year window for protecting brain health. However, for those who survive common health threats until the age of 75, the risk of developing dementia significantly increases. It rises to 20% by age 85 and 42% between the ages of 85 and 95. Overall, the lifetime risk of dementia after age 55 is 35% for men and 48% for women. This difference is largely attributed to the fact that women generally live longer than men, as noted by Coresh. Additionally, Black Americans have a slightly higher risk of 44%, compared to 41% for white individuals.
Yes, there are ways to help 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.
By: LAURAN NEERGAARD/AP News
