One of the challenges of longer life expectancies is dealing with an increased number of people suffering from conditions that come with old age, particularly dementia.
But the good news is that just as people are living longer, those who develop dementia do it much later in life than those of previous generations.
A study from the New England Journal of Medicine finds that the average age at which a person is diagnosed with dementia is now 85, up from 80 four decades ago. The study was based on more than 5,000 people over the age of 60 from 1975 until the early part of this decade.
It also found that the overall likelihood of a person developing dementia has declined significantly.
In the first five-year period observed, in the late 1970s and early 1980s, 3.6 percent of people developed dementia.
The rate declined in every subsequent period observed; to 2.8 percent in the late 1980s, to 2.2 percent in the late 1990s, and finally to 2.0 percent at the beginning of the 2010s.
The researchers lacked a clear explanation for the consistent improvement.
They therefore did not have much to recommend for further improving the situation. “The factors contributing to this decline have not been completely identified,” they wrote.
In general, better health reduces the chance of developing dementia, but it’s not clear what Americans have gotten right specifically, since there have been plenty of negative health trends during the past 40 years.
“The prevalence of most vascular risk factors (except obesity and diabetes) and the risk of dementia associated with stroke, atrial fibrillation, or heart failure have decreased over time, but none of these trends completely explain the decrease in the incidence of dementia,” explained the researchers.