The incidence of dementia is declining for more than three decades among the literate, revealed a new study.
The study published in the New England Journal of Medicine analyzed the incidence of dementia in participants of the Framingham Heart Study since 1975.
They estimated it for three decades and found the prevalence of dementia among the participants. The current analysis included 5,205 people age 60 and up and there was a total of 371 cases of dementia over the study period.
‘The risk of developing dementia is decreasing for people with at least a high school education in the US.’
The incidence of dementia in the late 70s to early 80s was 3.6 per 100, in late 80s to early 90s was 2.8 per 100, in late 90s to early 2000s was 2.2 per 100 and in late 2000s to early 2010s was 2.0 per 100.
They found that the dementia incidence fell by 22%, 38%, and 44% over the next three time periods, respectively compared with the first period. The overall risk reduced only among those who had, at least, a high school education, where they had about a 23% decline in risk per decade.
"In an analysis of data from the Framingham Heart Study, dementia incidence fell about 20% per decade since 1977, driven by declines in vascular dementia -- not Alzheimer's disease," said Dr.Sudha Seshadri, Boston University.
"Our study offers cautious hope that some cases of dementia might be preventable or at least delayed. However, it also emphasizes our incomplete understanding of the observed temporal trend and the need for further exploration of factors that contribute to this decline in order to better understand and possibly accelerate this beneficial trend," said researchers.
Reference: Sudha Seshadri, et al. "Incidence of Dementia over Three Decades in the Framingham Heart Study," N Engl J Med 2016; 374:523-532, DOI: 10.1056/NEJMoa1504327.