They’re the hi tech health trackers that can identify a faulty heartbeat, risky sleep disorder — or tell you when to stop drinking coffee. 

Now, smartwatches could even predict their wearers risk of dementia, scientists say.

According to Australian researchers, who tracked nearly 50,000 Brits wearing the devices, those who walked more regularly and at a faster pace were 40 per cent less likely to develop the condition or cognitive decline. 

Analysing their movements over a single week, they also found people with an early bedtime who clocked over nine hours of shut eye, increased their risk by around 60 per cent.

The scientists, today, said they hoped such smartwatches could ultimately be used as a screening tool for dementia. 

But, they cautioned that further research comparing these findings with other data gathered around the world, was first vital. 

Dr Lloyd Chan and Dr Maria Teresa Espinoza Cerda, research fellows at Neuroscience Research Australia, said: ‘This research demonstrates the potential for smartwatches and fitness trackers to be used in dementia screening. 

‘With their non-invasive and easy-to-use nature, these devices could offer valuable insights into a person’s dementia risk through their daily activity and sleep patterns.’

Being unable to learn new tasks and struggling to stay focused on a single task can be a sign of dementia — the memory-robbing condition plaguing nearly 1million Brits and seven million Americans

In the study, the researchers tracked 47,371 participants with an average age of 67, who all wore wrist-worn devices for up to seven days.

Over a follow-up of seven and a half years, 387 participants were diagnosed with dementia. 

Writing in the journal International Psychogeriatrics, the researchers said that for every 4.6cm per second increase in gait speed, dementia risk dropped by 32 per cent.

For every additional 3,200 steps walked, the risk also fell by 30 per cent on average.  

Compared to participants with normal sleep duration, those with ‘excessive sleep’ — more than nine hours — increased their odds of a dementia diagnosis by 50 per cent. 

And those with an early bedtime — before 9 pm — were 60 per cent more likely to be diagnosed than those with a ‘normal bedtime’. 

The scientists, however, acknowledged that the study had some limitations such as not including dementia-specific information from participants like familial dementia history. 

But using wrist sensors ‘acquires real-world data, resulting in a more accurate assessment of gait and sleep characteristics’, they noted. 

They hope that by raising awareness of risk factors – which change as we age – people can take steps to reduce their chances of getting the disease. 

It comes as a landmark study last July suggested almost half of all Alzheimer’s cases could be prevented by tackling 14 lifestyle factors from childhood. 

World-leading experts found two new risk factors — high cholesterol and suffering vision loss — were, combined, behind almost one in ten dementia cases globally.

They join 12 existing factors, ranging from genetics to smoking status, that experts have identified as increasing the risk a person would suffer dementia.

Discounting unavoidable factors, like the onset of ageing people’s genetic makeup, experts said smoking, lack of exercise, excessive alcohol consumption, social isolation and air pollution accounted for four in ten cases of the condition.

Experts claimed the study, published in the prestigious journal The Lancet, provided more hope than ‘ever before’ that the memory-robbing disorder that blights the lives of millions can be tackled.

Recent analysis by the Alzheimer’s Society estimates the overall annual cost of the dementia to the UK is £42billion a year, with families bearing the brunt.

An ageing population means these costs — which include lost earnings of unpaid carers — are set to soar to £90billion in the next 15 years.

Around 900,000 Brits are currently thought to have the memory-robbing disorder. But University College London scientists estimate this will rise to 1.7million within two decades as people live longer. It marks a 40 per cent uptick on the previous forecast in 2017

Alzheimer’s Disease is the most common form of dementia and affects 982,000 people in the UK. 

It is thought to be caused by a build-up of amyloid and tau in the brain, which clump together and from plaques and tangles that make it harder for the brain to work properly. 

Eventually, the brain struggles to cope with this damage and dementia symptoms develop.

Memory problems, thinking and reasoning difficulties and language problems are common early symptoms of the condition, which then worsen over time.

Alzheimer’s Research UK analysis found 74,261 people died from dementia in 2022 compared with 69,178 a year earlier, making it the country’s biggest killer.