WEAK muscles are closely linked to Alzheimer’s disease in older adults, a study suggests.

The US research showed a pattern of reduced Alzheimer’s risk with increasing muscle strength.

The strongest patients had 61% less chance of developing the disease than the weakest.

No reason for the association has yet been found, but it could involve energy production in the body or other hidden health problems, the scientists believe.

Alzheimer’s disease, the most common form of dementia, causes a progressive loss of memory and thinking ability. However it is also known to be associated with symptoms such as an impaired gait, depression and a weakened grip.

Researchers at Rush University Medical Center in Chicago studied 970 adults with an average age of around 80 who did not initially have Alzheimer’s.

Each was rated for mental function and given a physical strength score derived from testing 11 muscle groups.

At least one further evaluation was carried out over an average follow-up period of 3.6 years.

Of the total, 138 participants (14.2%) went on to develop Alzheimer’s.

Muscle strength scores ranged from minus 1.6 to 3.3 units. Every unit increase in initial muscle strength correlated with a 43% reduction in the risk of developing Alzheimer’s during the study period, the researchers found.