Dementia incidence may be declining, at least when it comes to people who have been awarded high school diplomas or more advanced qualifications, researchers have recently determined.
The findings were presented as part of the Framingham Heart Study on Wednesday, February 10, in the New England Journal of Medicine.
Research was commissioned and sponsored by the National Institutes of Health, most likely in order to assist one of its divisions called the National Institute on Aging.
The study was conducted by a team of experts led by Sudha Seshadri, board-certified neurologist and professor at Boston University School of Medicine.
Upon reviewing medical data pertaining to 5,200 individuals that have been tracked ever since 1975, it was determined that dementia incidence has been reduced by approximately 44% in the last four decades.
More precisely, the prevalence of new cases of Alzheimer’s disease and another forms of dementia has been estimated at around 2% at the end of the last decade and the beginning of the current one, after having been calculated at around 3.6% in the 1970’s and 1980’s.
The most obvious downward trend was identified when it came to vascular dementia, the second most frequently encountered form of dementia (surpassed solely by Alzheimer’s disease).
The condition manifests itself through cognitive decline, caused by impaired cerebral circulation. Blood vessels that transport oxygen, glucose and other nutrients to the brain become overly narrow, clogged or obstructed, sometimes resulting in a series of mini strokes.
Due to this brain damage, people who develop vascular dementia tend to experience short term memory loss, hallucinations, concentration difficulties, incontinence (absence of bowel or bladder control), disorientation even in familiar places, trouble carrying out day-to-day activities, emotional outbursts and inappropriate reactions.
It appears that ever since 1977, new vascular dementia diagnoses have been declining by 29% every decade, while the overall number of new dementia cases has been dwindling by about 20% every decade.
Now that study authors have discovered that the prevalence of dementia has been waning in recent decades, they are also speculating regarding possible explanations behind this downward trend.
As they argue, this condition is probably less common nowadays because the incidence of cardiovascular disease has also been falling.
Strokes and heart issues often heighten the probability of developing dementia, so it may be that as more emphasis has been placed on having a healthy diet and exercising regularly, more people have been enjoying good cardiovascular health, lowering their risk of being experiencing brain degeneration.
In addition, study authors also discovered that for people who are eventually affected by dementia, the onset of this condition usually occurs much later than before.
More precisely, nowadays the condition tends to be diagnosed around the age of 85, whereas decades ago the average age of onset used to be 80 years old.
Also, while in the past people who had strokes had a ninefold increased risk of developing dementia as well, because of improved medical care and assistance this susceptibility has been reduced significantly, stroke survivors being just around two times more vulnerable to progressive brain degeneration than other patients.
It must be noted however that a downturn when it came to dementia incidence in the last few decades has only been identified among people who have graduated high school or college.
As study authors explain, this may be because those who benefit from higher education tend to be more preoccupied with their health, being more aware of the risks associated with inadequate diets and sedentary lifestyles.
In addition, they are also more likely to benefit from preventive medical care, and to remain mentally active throughout old age.
Even though positive trends haven’t been identified among all socio-economic groups, according to Dallas Anderson, epidemiologist at the National Institute of Aging, the findings are still extremely promising, because they suggest that across generations the overall risk of suffering from dementia is decreasing, and the condition can be prevented, at least by some extent.
On the other hand, it is well worth mentioning that even though dementia incidence may be declining, the total number of Americans affected by this disorder is still expected to increase, as the population ages.
For instance, while 5.3 people in the United States suffer from Alzheimer’s disease nowadays, it is predicted that by 2025 the number of seniors affected by this disorder will soar to 7.1 million, reaching 13.8 million by 2050.
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