Your likelihood of getting dementia soars by nearly a third if you spend more than eight hours a day sitting down, according to a new study.
Researchers at York University in Canada analysed data from millions of adults aged over 35 to see how physical activity, time spent sitting, and sleep affect brain health.
They reviewed 69 previous studies that followed cognitively healthy people over time to see who went on to develop dementia.
The study, published in the open-access journal PLOS One, found that people who spent more than eight hours sitting down – akin to a typical working day – were 27 per cent more likely to develop dementia.
However, they noted that there are ways to protect against developing the debilitating degenerative disease, with both regular exercise and getting the ‘right amount’ of good sleep lessening the risk.
They found that people who exercised regularly had an average 25 per cent lower risk of developing dementia.
Sleeping less than seven hours a night raised the risk by 18 per cent, while sleeping more than eight hours increased it by 28 per cent.
Lead author Akinkunle Oye-Somefun said:’Regular exercise and good sleep are not just important for how we feel day to day – they may also play a role in protecting the brain decades later.
Regular exercise could reduce your risk of developing dementia later in life, a study has found
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‘We also found that prolonged sitting, even among people who are otherwise active, may increase dementia risk. It’s an area where more research is needed.’
Worldwide, an estimated 55 million people live with dementia, and numbers are expected to rise.
In the UK, around 982,000 people are affected, and this could reach 1.4 million by 2040.
Global costs are projected to hit £1.6 trillion by 2030, and with treatments currently limited, lifestyle changes are increasingly important.
Research, including work supported by Alzheimer’s Research UK, shows that up to 45 per cent of dementia cases could be prevented or delayed by addressing lifestyle and health factors, such as physical inactivity, high blood pressure, high cholesterol and social isolation.
‘Dementia develops over decades,’ said Oye-Somefun.
‘Everyday behaviours such as exercise, time spent sitting, and sleep may be linked to dementia risk.
‘Understanding these links could help support brain health across life.’
He added: ‘Some risk factors matter more at different stages of life. For example, managing hearing loss from midlife and staying socially connected later can make a real difference.’
Simple steps people can take include walking more, limiting long periods of sitting, keeping mentally active and staying socially connected.
