Every year, the ranks of those suffering from Alzheimer’s disease continues to grow, and new research may have identified a major risk factor for the disease that doctors had not considered before: physical frailty.
Link Between Frailty and Dementia?
In a new study published in the journal The Lancet Neurology, researchers have found evidence that physical frailty in older adults makes them more vulnerable to Alzheimer’s disease-related dementia and impacts the effect of changes in the brain has on dementia symptoms.
Older adults, those 59 years and older, who had higher degrees of physical frailty were also more likely to have Alzheimer’s disease-related changes in their brains as well as dementia symptoms. Researchers also found that those with a lower degree of frailty who also has Alzheimer’s related changes in the brain did not exhibit as many symptoms of dementia.
“By reducing an individual’s physiological reserve, frailty could trigger the clinical expression of dementia when it might remain asymptomatic in someone who is not frail,” says Professor Kenneth Rockwood from Dalhousie University, Canada, who was the lead researcher for the study.
“This indicates that a ‘frail brain’ might be more susceptible to neurological problems like dementia as it is less able to cope with the pathological burden.”
New Hope for Progress Against Alzheimer’s and Dementia Related Diseases
Research into Alzheimer’s disease has not yet come up with a complete picture of the debilitating disease that afflicts 10% of people over the age of 65. This research is a positive step in that it shows Alzheimer’s related brain changes alone do not cause dementia symptoms.
“This is an enormous step in the right direction for Alzheimer’s research,” says Rockwood. “Our findings suggest that the expression of dementia symptoms results from several causes, and Alzheimer’s disease-related brain changes are likely to be only one factor in a whole cascade of events that lead to clinical symptoms.
“Understanding how individual risk factors work together to give rise to late-life dementia is likely to offer a new way to develop targeted treatment options.”
More research needs to be done to confirm the link between frailty and Alzheimer’s, as the authors note in their study. The study itself relies on the cross-sectional analysis of pathology data from only one database, which only includes adults who live in Illinois.
Study Calls for Further Research
There is still much we do not know about Alzheimer’s disease. Early studies indicate that adults with Alzheimer’s related brain changes, such as amyloid deposition, can exhibit mild to no cognitive decline, while others who have fewer brain changes can suffer from dementia-related symptoms.
“While frailty is likely to reduce the threshold for Alzheimer’s disease-related brain changes to cause cognitive decline,” says Rockwood, “it probably also contributes to other mechanisms in the body that give rise to dementia, weakening the direct link between Alzheimer’s disease-related brain changes and dementia.”
“While more research is needed, given that frailty is potentially reversible, it is possible that helping people to maintain function and independence in later life could reduce both dementia risk and the severity of debilitating symptoms common in this disease.”
In particular, the authors hope future research illuminates the connection between cognition, biomarkers of Alzheimer’s related dementia, and frailty to fully establish causation. They also stress that a better consensus on what constitutes weakness in older adults is needed, as there is no one single definition. Further, the study looked at many older adults who were near death, so the connection between frailty and dementia symptoms could be coincidental to the onset of terminal decline.
Ultimately, Rockwood hopes that the study is only the beginning and that it will lead to more effective treatment options in the future. “In light of current knowledge on the cognitive frailty phenotype, secondary preventive strategies for cognitive impairment and physical frailty can be suggested,” including targeted physical, psychological, dietary, and cognitive interventions.