The number of Americans with dementia will increase in coming decades as the population ages, but not nearly as dramatically as some predictions suggest, according to experts challenging recent projections.
While a study published in January in Nature Medicine predicted that dementia cases would roughly double by 2060, other researchers argue the increase will be far more modest—perhaps just 10 to 25 percent by 2050.
“The notion that the number of people with dementia will double over the next 25, 30 or 35 years due to the aging of baby boomers is widespread, it’s pervasive—and it’s wrong,” said Eric Stallard, an actuary and co-director of the Biodemography of Aging Research Unit at Duke University.
The Duke researchers point to a steady decline in age-specific dementia rates over the past 40 years. Their analysis found that among 85- to 89-year-olds born in 1905, about 23 percent developed dementia. For those born in 1935 who reached their late 80s, the rate fell to about 11 percent, with projections for those born between 1945 and 1949 at approximately 8 percent.
Similar improvements have been documented in England and China, according to Dr. John Beard, a medical epidemiologist at Columbia University’s Mailman School of Public Health.
Experts attribute these declining rates to several factors: rising education levels, reduced smoking, and improved treatment for conditions like high blood pressure and high cholesterol. The Lancet Commission on dementia has identified 14 modifiable risk factors that could lead to greater declines, including greater use of hearing aids and reduced air pollution.
However, these positive trends could reverse. Increasing obesity and diabetes rates might drive dementia numbers up, while health disparities could mean different outcomes for different populations. Older women, Black Americans, and carriers of the APOE4 gene face greater risk of developing the condition.
Public health policies will play a crucial role in determining future trends, experts say. Access to healthcare, environmental regulations, and availability of new medications could all significantly impact dementia rates in the decades ahead.
