Risk factors include hearing loss, high blood pressure, and diabetes, according to researchers.
Rising rates of dementia have frustrated medical experts for years, but a new report suggests that adopting certain lifestyle changes could prevent as many as one-third of dementia cases worldwide.
While dementia has long been considered to “be neither preventable nor treatable,” the experts reported that approximately 35 percent of dementia cases are connected to nine risk factors: “education, midlife hypertension, midlife obesity, hearing loss, late life depression, diabetes, physical inactivity, smoking, and social isolation.”
Targeting these risk factors could “contribute to prevention or delay of dementia,” the authors wrote.
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Globally, an estimated 47 million people were living with dementia in 2015. That number is expected to rise to 66 million cases by 2030, and 131 million by 2050, according to the report.
Dr. Keith Fargo, director of Scientific Programs and Outreach, Medical and Scientific Relations at the Alzheimer’s Association, said the report gives concrete information to people afraid they can do nothing to lower their dementia risk.
“Lifestyle issues have been something that people have thought about for a long time,” he said. “It gets across that these are things that people can modify.”
Fargo said the report is especially helpful since it highlights the risk factors present decades before a person will show symptoms of dementia.
“They have new model of dementia risk. It’s risk across the whole life span,” Fargo explained. “We’re not looking at just as you get older.”
The authors found that less education in childhood — defined as ending education before secondary school — was associated with an 8 percent increased risk of developing dementia. The researchers found that education likely adds to a person’s “cognitive reserve,” which means they may be able to better function with initial symptoms of dementia, and delay the onset of the condition.
Additionally, the authors found that midlife obesity, hypertension, and diabetes increased the risk of dementia. These conditions can affect insulin mechanisms and inflammation in the body, which can impair cognition.
One new factor that the authors focused on was hearing loss. They found that hearing loss could add to the “cognitive load” on a brain already strained and at risk for dementia. Additionally, hearing loss can cause people to become withdrawn and less social — possibly leading to depression or accelerating atrophy in the brain.
The authors calculated that addressing childhood education, hypertension, obesity, and hearing loss in midlife could reduce a person’s chances of developing dementia by nearly 20 percent.
“Available interventions and care can improve the trajectory of symptoms and the family’s ability to cope with them, and thus change the experience of the course of dementia,” the authors wrote.
“The potential magnitude of the effect on dementia of reducing these risk factors is larger than we could ever imagine the effect that current, experimental medications could have.”
Dr. Lon Schneider, MD, professor of psychiatry and the behavioral sciences at the Keck School of Medicine of USC, said in a statement released today, “Mitigating risk factors provides us a powerful way to reduce the global burden of dementia.”
The report was complemented by the announcement of a new study aimed at understanding more about how these lifestyle factors affect cognitive decline.
Officials from the Alzheimer’s Association announced Wednesday they will launch a two-year study to see if lifestyle interventions including “physical exercise, nutritional counseling and modification, cognitive and social stimulation, and improved self-management of medical conditions,” can reduce the risk of cognitive decline and dementia.
Fargo said the study, which will include more than 2,500 people, is based on a similar study out of Finland that found promising signs of how changing lifestyles can lower the risk of full-blown dementia symptoms.
Fargo explained that delaying the dementia, even just by a few years, can have huge consequences for someone in their 80s or 90s. For example, a person who is 95 years old, and who’s dementia is delayed two years, may end up dying from unrelated causes and not have to go through the pain and fear related to dementia.
“You can prevent dementia cases by delaying onset,” said Fargo.