A new study has revealed that the onset of Alzheimer's disease may be linked to physical frailty, a common condition among older people.
Researchers in the US examined the brains of 165 people who had participated in a larger community study of aging and who had been measured yearly for symptoms of physical frailty including grip strength, walking pace and tiredness.
After death, brains were examined for the plaques and tangles which are the pathological indicators of Alzheimer's disease. The results showed that 36% of the group had dementia or showed signs of memory loss.
Frailty was twice as high in people with a high level of Alzheimer's disease pathology compared with those with a low pathology, the researchers concluded.
Commenting on the findings, Rebecca Wood, chief executive of the Alzheimer's Research Trust, said: "This research suggests that Alzheimer's shares a common cause with frailty.
"It may be that frailty is an early warning sign of a high risk of dementia. But this is not yet clear, and more research on a wider scale with a more diverse cohort is needed.
"Unfortunately dementia research is severely underfunded in the UK, and much more is needed if we are to understand this condition which affects 700,000 people."