Despite concerns about an explosion of dementia cases in an aging population over the next few decades, a new study co-authored by researchers from Boston University School of Public Health (BUSPH) suggests that the rate of new cases of dementia actually may be decreasing over time.
For the new study, published in the New England Journal of Medicine, researchers looked at the rate of dementia at various ages and attempted to explain the reason for a decreasing risk of dementia over a period of almost 40 years. They considered risk factors such as education and smoking, and medical conditions including diabetes, high blood pressure, and high cholesterol.
Looking at four distinct periods in the late 1970s, late 1980s, 1990s, and 2000s, the researchers found that there was a progressive decline in the incidence of dementia at a given age, with an average reduction of 20 percent per decade since the 1970s. The decline was more pronounced with a subtype of dementia caused by vascular diseases, such as stroke.
The authors said that while 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, none of those trends completely explains the decrease in the incidence of dementia— but that better management of cardiovascular diseases and strokes and their risk factors could offer new opportunities to slow the projected burden of dementia.
To read more about the study, go to: http://www.bu.edu/sph/2016/02/23/age-specific-dementia-rates-falling-while-new-cases-rise/