Losing muscle while getting older could be an important warning sign for dementia, according to new research.

Researchers from Curtin University have helped determine those with sarcopenia - a condition where people lose a greater amount of muscle mass, strength and physical function as they get older - were at 42 per cent more risk of developing dementia.

The finding could offer new considerations for how to lower dementia risk.

“It’s not just about how much you weigh – maintaining muscle strength and function also appears to be important as we age,” lead researcher Dr Uraiporn Booranasuksakul from Thailand’s Burapha University said.

“Our findings suggest losing muscle could be an important warning sign for dementia risk.”

The impact of weight on dementia is not so simple, however, with the study revealing that while being obese before age 65 heightened risk by nine per cent, people over 65 and with obesity issues actually had the risk decrease.

Those findings are part of what makes the degenerative disease “complex” to understand, according to Curtin University professor Mario Siervo.

“We found that obesity in middle age was linked to a higher risk of dementia, but this relationship changed in later life. This does not mean people should gain weight as they get older,” Professor Siervo said.

“Rather, it shows us that the relationship between body weight, ageing and dementia is complex.

“There is still a lot we don’t know about how changes in muscle and body fat interact over time,” Professor Siervo said.

Curtin’s findings reinforced how important exercise, mobility and stability is for people as they age, Chairman and Head of Research and Partnerships at Alzheimer’s WA, Professor Warren Harding said.