Despite widespread projections that the number of dementia patients is on the rise, two studies published this week in Europe show dementia rates may actually be falling—sharply, with one study showing rates having fallen off by about a quarter over the past 20 years.
The findings are in contrast to estimates placing the number Americans 65 and older with Alzheimer’s disease at 5 million currently, and expected to rise 40% by 2025, according to the Alzheimer’s Association. The expected boom has sparked interest in memory care development nationwide, as existing units number around 75,000 in the top 100 metro areas tracked by the National Investment Center (NIC) for the Seniors Housing & Care Industry
The new results are being attributed largely to better overall health in developed countries; in England and Wales where one study was conducted, the dementia rate has fallen from 8.3% to 6.2% among those who are 65 and older since 1991; a decline of 24%.
“This study provides compelling evidence of a reduction in the prevalence of dementia in the older population over two decades,” the research states through its publication in medical journal the Lancet.
“The scale of the reduction that we identified is substantial and is in line with major reductions in risk factors in higher income countries, which have been modified by societal changes such as improvements in education, and prevention and treatment strategies in recent decades,” it states.
The number of dementia patients in care settings, however, has risen, the research finds, attributing the increase to a smaller proportion of people living in care settings overall today, versus two decades ago.
A second study published this week explored the cognitive abilities of people in their 90s in Denmark, as many more are living into their ninth decade in high-income countries.
Examining cohorts of people born in 1905 and 1915, the research finds contrast between the two populations, though they were tested two years apart.
“Despite being 2 years older at assessment, the 1915 cohort scored significantly better than the 1905 cohort on both the cognitive tests and the activities of daily living score, which suggests that more people are living to older ages with better overall functioning,” the research finds.
The results were received with mixed response in the U.S.
“Dallas Anderson, an expert on the epidemiology of dementia at the National Institute on Aging, the principal financer of dementia research in the United States, said the new studies were ‘rigorous and are strong evidence,’ according to a New York Times report. “He added that he expected that the same trends were occurring in the United States but that studies were necessary to confirm them.”
Yet the Alzheimer’s Association expressed its view on the data, that while proportionally, the rate of dementia may be growing at a slower pace, the number of those suffering from it is going up.
“It is important to look at the prevalence of dementia over time and, while approaches to prevalence calculations vary, the number of people who are developing Alzheimer’s or another form of dementia is expected to rise due to the aging of the population,” the association said in a statement.
“…even if the percentage of new cases in the population is going down (and we don’t know for certain that it is) because the older population is growing at such a fast rate, dementia prevalence – that is, the total number of people with the disease – is continuing to rise. In other words, it is likely that prevalence is not going down but it could be increasing at a slightly slower pace.”
Written by Elizabeth Ecker