The research was carried out in the ‘Journal of Neurology, Neurosurgery, and Psychiatry‘.
The study found that frailty is a strong risk factor for dementia, even in people at high genetic risk for dementia, and that it could be changed by a healthy lifestyle.
The international team from Dalhousie University and Nova Scotia Health in Canada and the University of Exeter in the UK worked with data from more than 196,000 adults over the age of 60 in the UK biobank. They calculated the participants’ genetic risk and used a previously developed frailty score that reflects the accumulation of age-related symptoms, signs, disabilities, and illnesses. They analyzed this along with a healthy lifestyle score and who later developed dementia.
“We see more and more evidence that meaningful measures in life can significantly reduce the risk of dementia,” said lead author Dr. David Ward of Dalhousie University’s Geriatrics Department.
“Our research is a huge step forward in understanding how reducing frailty could help dramatically improve a person’s chances of avoiding dementia, regardless of their genetic predisposition to the self-preventable disease. In our study, this appeared to be possible in part through a healthy lifestyle, ”he added.
During the UK Biobank’s 10-year study period, 1,762 participants were diagnosed with dementia from hospital admissions – and these people were much more likely to have high levels of frailty prior to diagnosis than those who did not develop dementia.
The importance of preventing or reducing frailty was highlighted when researchers looked at the effects of genetic risk in people with different degrees of frailty. Genetic risk factors had their expected effect on dementia risk in healthy subjects, but genes became less and less important in the most frail subjects. These frail study participants had a high risk of dementia regardless of their genes.
Even in those with the highest genetic risk for dementia, the researchers found that the risk was lowest in fit people and highest in people in poor health, which was measured as a high degree of frailty. However, the combination of high genetic risk and high frailty turned out to be particularly disadvantageous, as the participants had a six times higher risk of dementia than participants without either of the two risk factors.
Compared to study participants with a low degree of frailty, the risk of dementia in study participants with a high degree of frailty was more than 2.5 times higher (268 percent) – even after controlling numerous genetic determinants of dementia.
The research identified ways to reduce the risk of dementia. Study participants who reported more commitment to healthy lifestyles were less likely to develop dementia, in part because they had lower levels of frailty.
“Risk of dementia reflects genetic, neuropathological, lifestyle and general health factors, which in turn lead to a range of abnormalities in the brain,” said Dr. Kenneth Rockwood, Professor of Geriatrics and Neurology and Kathryn Allen Weldon Professor of Alzheimer’s research at Dalhousie University, and the senior medical director of the newly established Network for frailty and elderly care bey Nova Scotia Health.
“Our study is an important step forward on the role of frailty, which appears to have a unique and potentially modifiable avenue in influencing the risk of dementia. This is an incredibly exciting prospect that we urgently need to explore in order to help the growing number of people around the world who are affected. “Dementia,” he added.
Co-author Dr. Janice Ranson, from the Exeter University Faculty of Medicine, said, “These results are extremely beneficial and show that dementia is not inevitable, even if you are genetically at high risk. We can take meaningful steps to reduce our risk to brain health and help people stay mobile and independent longer in later life. ”