Feb. 7, 2013 -- The number of people with Alzheimer's may triple by 2050, from 4.7 million in 2010 to 13.8 million by 2050, a new study shows.
"These are staggering numbers," says researcher Jennifer Weuve, MPH, ScD, of the Rush Institute for Healthy Aging in Chicago. "The ramifications for society and family caregivers in particular are huge."
Still, "this is not really a surprise," she says. "It's a bit like climate change. We've known about it for years but we haven't done much to stop it. Our data drum home the message that research into the prevention and treatment of Alzheimer's must be a priority, as well as developing better ways of managing patients with the condition and helping caregivers."
Weuve says that trying to estimate the number of Alzheimer's cases in the country is complicated. Medical and public health agencies are not good at documenting these statistics, and Alzheimer's is hugely under-diagnosed.
"A diagnosis of Alzheimer's requires that you show up in a clinic and a physician actually thinks about dementia. Many patients go to their primary care doctor for something else, and although they may come across as confused, the doctor just puts this down to age and never formally diagnoses Alzheimer's, so about half of Alzheimer's cases go undiagnosed. Because of this, we had to be resourceful when trying to work out how many cases there actually were," she says.
To get around this problem, Weuve and her colleagues based their estimates on 10,000 adults, aged 65 and older, who were tested for Alzheimer's as part of the Chicago Health and Aging Project.
They then worked out the prevalence, or number of cases, of Alzheimer's disease in the U.S. in 2010 according to age, sex, educational level, and race by using U.S. census data.
Out of the 4.7 million people with Alzheimer's in 2010, the researchers estimate that just over a half-million were between 65 and 74 years, 2.3 million were between 75 and 84 years, and 1.8 million were 85 years or older.
This gave an estimate of 13.8 million people with Alzheimer's in 2050, of whom 7 million would be aged 85 or older.