Nearly one in two Americans will develop dementia during their lifetime, according to researchers who say the condition is vastly underestimated.
A new study from researchers at New York University shows that the risk of someone developing dementia after age 55 is 42 percent – more than double the risk predicted in previous studies.
This translates to almost 1 million additional new cases of some form of the disease per year by 2060.
Currently, nearly 8 million Americans suffer from some form of dementia, and approximately 500,000 new cases are diagnosed each year.
The study authors attribute previous underestimates to unreliable documentation of dementia in medical records and on death certificates, undiagnosed symptoms or early-stage cases, and the underreporting of the disease in minorities – who are at higher risk but often lack access to reliable care.
They said: ‘Lifetime risk of dementia is a critical public health measure that can raise awareness, increase engagement in prevention and inform policymaking… The results highlight the urgent need for policies that promote health-related aging , with an emphasis on health equity. ‘
Published in the journal Nature Medicine, the study examined 15,800 adults who participated in the Atherosclerosis Risk in Communities (ARIC) study from 1987 to 2020.
The ARIC is one of the longest running health surveys and collects a wide range of measures from respondents, including cognitive status.
The overall risk of developing dementia is 42 percent. In women this is 48 percent and in men the risk is about 35 percent
The above shows the increase in the risk of developing dementia according to age
To measure cognitive skills, participants underwent questionnaires, cognitive tests and physical examinations.
Researchers used an algorithm to determine the diagnosis of dementia based on criteria from the National Institute on Aging-Alzheimer’s Association.
A panel of experts then reviewed the cases and made a final diagnosis of dementia.
Study author Dr. Josef Coresh, founder and director of the Optimal Aging Institute at NYU Langone, said the team’s study “predicts a dramatic increase in the burden of dementia in the United States in the coming decades.”
There is no cure for dementia; only medications and therapies to control symptoms.
The overall risk of developing dementia is 42 percent, but in women it is 48 percent. Men have a risk of about 35 percent.
Black people are also at increased risk: 44 percent overall to 41 percent among white Americans.
There were 514,000 new cases of dementia among Americans in 2020, but that will rise to 730,000 by 2030 and 1.03 million by 2060.
For women, the annual incidence is expected to increase from 325,000 in 2020 to 458,000 in 2030 and to 640,000 in 2060.
The above shows the risk that men (blue line) and women (red line) have of developing dementia, according to age
For men, the figures will rise from 198,000 to 282,000 to 405,000 in 2020, 2030 and 2060 respectively.
People aged 75 to 84 will see the largest increase, from 250,000 in 2020 to 487,000 per year in 2060.
While more white people will be diagnosed with dementia between 2020 and 2060, the rate at which cases will rise is faster among Black Americans and will triple over the next thirty years.
The number of diagnoses will increase from 60,000 in 2020 to 179,000 per year in 2060.
Although the root cause of dementia is still debated, scientists believe the disease is likely the result of an abnormal buildup of proteins – amyloid and tau – in and around brain cells.
In Alzheimer’s patients, amyloid proteins are not effectively removed from the body and eventually form plaques in the brain.
In addition, tau proteins detach from neurons and form tangles, causing neurons to die.
When neurons die, messages cannot be delivered as effectively by the brain, which scientists believe is the cause of the thinking problems in dementia.
Genetics also plays a strong role in Alzheimer’s risk, and in 2022 researchers identified 31 new genes that appear to influence processes involved in the disease.
Growth estimates previously predicted that the number of Alzheimer’s patients would rise to nearly 13 million by 2050 (illustrated above), but NYU’s new research has much higher predictions
Of the genes, one called APOE-e4 has the strongest impact on risk.
Everyone inherits one of three forms of the APOE gene from their parents – e2, e3 or e4 – and scientists found that having the e4 form most increases a person’s risk of developing the disease, especially if he or she develops it at a younger age.
African Americans are more likely than other races to have this gene.
In the NYU study, the risk of dementia in people with the APOE-e4 gene ranged from 40 to 60 percent.
However, previous researchers emphasized that this is still a new discovery and that there are other aspects that contribute more to increased risk that need to be addressed.
Dr. Coresh said the projected increase in the disease is partly related to longevity and the fact that people are living longer — especially women — and that nearly 60 million Americans are now over 65.
He added: ‘The upcoming population growth in dementia cases poses a significant challenge for healthcare policy makers in particular, who should refocus their efforts on strategies to minimize the severity of dementia cases, as well as on plans to increase provide healthcare services to people with dementia. .’
Dr. Coresh also said more must be done to address racial inequities in health care, with health policies needing to increase efforts in Black communities to improve child education and nutrition, which previous research has shown to be beneficial in preventing cognitive decline later in life.