A third of all Alzheimer’s cases might be prevented if people would change certain unhealthy lifestyle behaviors, according to a study published Monday by researchers from the University of Cambridge in Great Britain.
Using existing data, the researchers identified seven key modifiable risk factors for Alzheimer’s disease and then developed a statistical model that estimated how many cases of the devastating neurological disease might be prevented if the risks were reduced across entire populations.
The identified risk factors were
- high blood pressure at midlife (ages 35 to 64)
- obesity at midlife
- physical inactivity
- a low level of education
Globally, having little education was identified as the main risk factor for Alzheimer’s disease — primarily due to its high prevalence. The study’s statistical model linked about one in five cases of Alzheimer’s disease to this risk factor.
By comparison, the model linked only one in 10 cases of Alzheimer’s in the United States and Europe to being poorly educated.
The risk factor most associated with Alzheimer’s in the United States and Europe was physical inactivity — defined as not doing either 20 minutes of vigorous exercise on three or more days per week or 30 minutes of moderate activity on five or more days per week.
It’s currently estimated that about one-third of American and European adults are physically inactive.
The second and third modifiable risk factors most associated with Alzheimer’s — at least in the U.S. — were smoking and chronic depression.
Small changes, big effect
After doing some further analyses, the researchers estimated that if the prevalence of each of the seven risk factors were to drop by only 10 percent per decade, nearly 9 million cases of Alzheimer’s disease could be prevented worldwide by 2050.
In the United States, a 10 percent reduction would reduce the rate of Alzheimer’s disease by 8.7 percent in 2050 — a decline that would mean about 800,000 fewer individual cases.
It’s currently estimated that the number of individuals with Alzheimer’s disease will more than triple globally by 2050, rising to 106 million from the 30 million that was estimated in 2010, according to background information in the study.
In the U.S., almost 14 million people are expected to have Alzheimer’s disease in 2050.
Because the analyzed data involves entire populations of people — such as all the people who live in the United States — this study’s findings should not be interpreted as being predictive of what might happen to a particular person.
For example, the study predicts that if every adult in the U.S. were physically active, then 21 percent fewer Americans would develop Alzheimer’s disease.
But there’s nothing in this statistical model that can identify just who those individuals would be.
‘A daunting task’
As Dr. Geert Jan Biessels, a neurologist at the University Medical Center in Utrecht, Netherlands, notes in a commentary that accompanies the study, “A reduction in the prevalence of these [risk] factors would certainly make the world a different place, and the societal and health effects would extend far beyond the prevention of Alzheimer’s disease.”
Yet undertaking any kind of population-level intervention is “a daunting task,” he adds.
Indeed. Particularly when such interventions often run smack up against corporate and other big-money interests.