RACING legend Sir Jackie Stewart has spoken of his wife Lady Helen's struggle with dementia and his campaign for more research into the disease.

The former Formula 1 driver told of the family's shock at 75-year-old Lady Helen's diagnosis but he said that they are determined to help find a way to advance the treatment of sufferers through his charity Race Against Dementia.

He said there also is a stigma attached to dementia that has to be overcome, the Sunday Mail reported.

Sir Jackie, 78, said the couple and their son had already beaten other health hurdles but: "This is the biggest challenge I've ever taken on.

"Helen's had cancer, Paul's had cancer, I had cancer - nothing very serious but we all had it.

"Now, suddenly, Helen gets dementia and everybody just shakes their head and says, 'I'm sorry, Jackie, we don't have any answers, no cures, no preventative medicine.'

"So that's why we've got a big push going.

"That's why I called my charity Race Against Dementia. We can't wait another 25 years."

He has put £1million of his cash into the charity and the racing legend raised £540,000 to combat dementia at a Monaco fundraiser last month.

He said: "It's likely to be too late to find a cure for Helen. But why can't we find a drug that would at least give Helen more ease of the experience?

"My goal is to not only find a cure but, perhaps even more importantly, to find a preventative medicine for it.

"I don't know if Helen appreciates me going public about her diagnosis sometimes."

He continued: "I can understand that but, on the other hand, it's the only way for us to raise money for other people.

"This is not just about Helen - it's a global problem.

"I don't know why there's a stigma.

"We're happy to talk about cancer - it's a strange thing."

Lady Helen was diagnosed with frontotemporal dementia four years ago.

However, Dumbarton-born Sir Jackie said: "She's still struggling with admitting that she's got dementia.

"A big consolation is she remembers me still.

"Helen likes going out for dinner or lunch. We're lucky we can do these things. I know that not everybody can."

He was also reported as saying: "The worst moment is still being told Helen had dementia.

"It's a terrible shock to the family to watch this. It's a real shock because it affects your whole life.

"It's not an easy one to deal with - the deterioration of somebody you love.

"There has been a lot of change in the past year. Her walking, for example, is definitely less good and we have a wheelchair for her.

"We basically have to have two neuro nurses with her all the time for 24 hours because she falls at night and she can't get up.

"I'm lucky enough I'm in a position to look after her personally. Very few people can afford that.

"Now it's very important that nobody thinks Helen is being supported by Race Against Dementia. That's not charged against the charity. That comes out of my pocket."

He added: "I'm taking a Formula 1 approach to this. And F1 is a good example because we find solutions faster than any industry, including the aerospace industry.

"Nobody's ever approached it like this before so it's a new way of doing business and tackling this.

"At the moment, it's not like cancer, where if you catch it early enough, you can get cured. In the case of Helen, this is an illness that so far nobody has the answer to. That must change."