Researchers now estimate that 46.7 million U.S. adults have some indication of Alzheimer’s disease, the result of a new method to identify brain changes that are known to lead to the degenerative disease.
In addition, about 6 million Americans are known to have Alzheimer’s or mild-cognitive impairment, in the most accurate assessment of the scope of the disease, according to a new study.
“We’re now getting new numbers on the number of people who don’t yet have Alzheimer’s disease/dementia but are in earlier states of the disease,” Dr. Ron Brookmeyer, the study’s lead author, told The Washington Times.
Researchers use the term “pre-clinical” for the specific brain changes and presence of neural-clogging proteins that indicate Alzheimer’s but haven’t caused any symptoms yet.
Of the 46.7 million Americans with some indication of the disease, roughly 1-in-7 will progress to dementia, said Dr. Brookmeyer, professor of biostatistics at the University of California-Los Angeles.
“We now are being able to develop these models for this pre-clinical period and look at the whole continuum of the disease process,” he said.
“The importance of all of this is that resources needed to care for patients varies tremendously over the course of the illness,” he said, adding that a diagnosis at 90 years old will require a much different treatment plan than a diagnosis at 65 years old.
The researchers estimate that by 2060, 15 million people will have Alzheimer’s-related dementia and of those, 4 million will require intensive care services such as living in a nursing home.
The study, funded by the National Institutes of Health, was published Thursday in the journal Alzheimer’s and Dementia.
Dr. Dallas Anderson, a program director in the neuroscience division at the National Institute on Aging, told The Times that the study is the first to count people who have the brain pathology linked to Alzheimer’s.
“We really don’t know who these people are — these 46.7 million — because the kinds of tests that are being done to identify people like that are in research studies, they’re not in clinical practice,” Dr. Anderson said. “Even so, it’s important to have this hypothetical number out there that suggests the scope of the problem.”
“It’s the first study to really try to count people who have brain pathology that’s linked to Alzheimer’s, without having the condition, to produce a number that we’ve never seen before,” he added.
Alzheimer’s disease is incurable, but research has shown that preventive measures — eating well, physical activity, being mentally active and social — can help stave off the disease.
Alzheimer’s research moved to the forefront of the national agenda in 2011 with the enactment of the National Alzheimer’s Project Act, which led to development of a task force to advance prevention and treatment options by 2025.
Last month, Microsoft founder Bill Gates announced a $100 million donation for research, with half going to start-up ventures and the other $50 million going to the Dementia Discovery Fund, a public-private partnership advancing research.
The current approach to care is a mix of medication and therapy to manage symptoms or delay their severity. Having a better understanding of how Alzheimer’s develops and progresses will better help scientists focus on prevention.
“I think ultimately we want to have some kinds of prevention strategies or treatments that will sort of nip the condition in the bud,” Dr. Anderson said. “The best thing is to stop it before too much damage is done. Right now we’re just trying to understand the pre-clinical aspect of the condition.”