A ground-breaking study into the link between physical health and dementia is being launched in west London.

Leading an unhealthy lifestyle is believed to put people more at risk of developing the brain condition, which affects people’s memory, speech and understanding.

But until now the link with obesity, smoking and lack of exercise – the same factors behind cancer and heart disease – has been based solely on studies of dementia patients aged 60 and above.

For the first time, a major trial is being carried out on people aged 40 to 59 to see if changing your lifestyle in middle age can help reduce your chances of developing dementia.

West London Mental Health Trust and Imperial College are leading the ‘Prevent’ project, a three-year nationwide trial involving 300 subjects.

They are looking for healthy volunteers in the age bracket, both with and without a family history of dementia, to take part in the study, funded with a £250,000 grant from the Alzheimer’s Society.

Dr Craig Ritchie, an honorary consultant psychiatrist for WLMHT and senior lecturer at Imperial, said: “This is about moving the focus from those who already have dementia to a younger age group, because prevention’s better than cure.

“It was the child of a (dementia) patient who set the study in motion by asking ‘what’s the cause of dementia and what can I do to avoid getting it?’ The answer was that we didn’t really know.”

The study was launched this month to tie in with World Mental Health Day yesterday (Thursday), held to raise awareness of mental health difficulties and tackle the stigma which is still attached.

There were information stands at hospitals across west London on the day, including Ealing and West Middlesex hospitals, and at Westfield shopping centre, in Shepherds Bush, WLMHT staff and volunteers handed out ‘sad biscuits’ and ‘seeds of hope’ to highlight the issue.

More than one in four people will experience a mental health problem every year in Britain, yet there is still an ongoing battle to fight public misconceptions.

A ‘mental patient’ Halloween costume was recently advertised by Asda, before being hurriedly withdrawn in the face of a huge public backlash.

“We’ve got a long way to go before people are fully aware of the prevalence of mental health difficulties and the impact they have on people’s lives,” said Dr Ritchie.

“People need to be encouraged to talk openly about their mental health difficulties if we’re going to reduce the stigma.

“There was a sense of disbelief about the Halloween costumes, especially when you imagine how many people must have seen it before it was approved for sale.”

For more information about the Prevent study, and to get involved, email katie.wells@wlmht.nhs.uk.