One in two Americans will get dementia in their lives as researchers warn disease is vastly underestimated
Nearly one in two Americans will develop dementia in their lifetimes, according to researchers who say the condition is being vastly underestimated.
A new study by researchers from New York University found the risk of someone developing dementia after 55 years old is 42 percent – more than double the risk projected by previous studies.
This translates into nearly 1million more new cases of some form of the disease per year by 2060.
Currently nearly 8million Americans currently have some form of dementia and there are around 500,000 new cases diagnosed per year.
The study authors attribute previous underestimations to unreliable documentation of dementia in health records and on death certificates, undiagnosed symptoms or early-stage cases and the under reporting of the disease in minorities – who are at higher risk but often lack access to reliable care.
They said: ‘The lifetime risk of dementia is a critical public health measure that can raise awareness, enhance engagement in prevention and inform policymaking… the results highlight the urgent need for policies that enhance health aging, with a focus on health equity.’
Published in the journal Nature Medicine, the study looked at 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 studies looking at health that collects a wide array of metrics from respondents, including cognitive state.
The overall risk of developing dementia is 42 percent. It is 48 percent in women and men have a risk of about 35 percent
The above shows the increase in risk of developing dementia by age
To measure cognitive abilities, participants underwent questionnaires, cognitive tests and physical exams.
Researchers used an algorithm to determine a dementia diagnosis based on criteria set by the National Institute on Aging-Alzheimer’s Association.
A panel of experts then reviewed the cases and made a final dementia diagnosis.
Study author Dr Josef Coresh, founding director of Optimal Aging Institute at NYU Langone, said the team’s study forecasts ‘a dramatic rise in the burden from dementia in the United States over 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 it is 48 percent in women. Men have a risk of about 35 percent.
Black people also have an elevated risk – 44 percent overall to 41 percent overall among white Americans.
There were 514,000 new cases of dementia among Americans in 2020, but that will rise to 730,000 in 2030 and 1.03million in 2060.
For women, the annual incidence is projected to rise from 325,000 in 2020 to 458,000 in 2030 to 640,000 in 2060.
The above shows the risk men (blue line) and women (red line) face of developing dementia by age
For men, the rates will rise from 198,000 to 282,000 to 405,000 in 2020, 2030 and 2060, respectively.
People 75 to 84 years old will have the highest increase, growing from 250,000 in 2020 to 487,000 per year by 2060.
While more white people will be diagnosed with dementia between 2020 and 2060, the rate at which cases will rise is higher among Black Americans and will triple over the next three decades.
Diagnoses will rise from 60,000 in 2020 to 179,000 per year by 2060.
While the main cause of the dementia is still debated, scientists believe the disease is likely to be the result of an abnormal build-up of proteins – amyloid and tau – in and around brain cells.
In Alzheimer’s patients, amyloid proteins are not effectively cleared from the body and eventually form plaques in the brain.
Additionally, tau proteins detach from neurons and form tangles, causing neurons to die.
When neurons die, messages can’t be delivered as effectively throughout the brain, which scientists believe is what causes the thinking difficulties in dementia.
Genetics also play a strong role in the risk of Alzheimer’s and in 2022 researchers identified 31 new genes that appear to affect processes that play a role in the disease.
Estimates for the growth previously projected the number of Alzheimer’s patients to rise to nearly 13million by 2050 (illustrated above), but NYU’s new research has far 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 discovered having the e4 form increases a person’s risk the most of developing the disease – especially developing it at an earlier age.
African Americans are more likely than other races to have this gene.
In the NYU study, the risk of dementia among people with the APOE-e4 gene ranged from 40 to 60 percent.
However, previous researchers stressed this is still a new discovery and there are other aspects that contribute more to an increased risk that need to be addressed.
Dr Coresh said the expected rise in the disease is partly tied longevity, and the fact that people are living longer – especially women – and that nearly 60million Americans are now older than 65.
He added: ‘The pending population boom in dementia cases poses significant challenges for health policymakers, in particular, who must refocus their efforts on strategies to minimize the severity of dementia cases, as well as plans to provide more health care services for those with dementia.’
Dr Coresh also said more needs to be done to address racial inequities in health care, with health policies needing to increase efforts in Black communities to improve childhood education and nutrition, which previous research has shown is beneficial in preventing cognitive decline later in life.
