SCOTTISH racing legend Sir Jackie Stewart has revealed his wife is suffering from dementia, saying her mind is "vanishing" from the disease.

The three-time Formula One Champion said Lady Helen, 75, retains her "feisty willpower" but refuses to accept she has the condition and now requires help with everyday tasks.

Sir Jackie has launched a charity, Race Against Dementia, to fund research with the aim of developing a cure for the disease, although he has acknowledged it is probably too late to save his wife.

The couple have been together for 54 years and have two sons and nine grandchildren.

Sir Jackie said that his wife was the "original pit lane girl", and that he had immediately fallen in love with her razor sharp mind when they met.

He said: "I have watched Helen change before my very eyes for the last two years. It is her mind that is vanishing. Her short term memory is shot – she never remembers where I am even after I repeatedly tell her.

“ have in front of me my wife, my partner, who still has this feisty willpower but is not accepting that she has dementia. It is basically like having worthless determination.

"She knows there isn’t a cure, and that may be a reason why she doesn’t accept she has the illness, perhaps it makes everything a little more real?”

He added: “This is where I step in. I have accepted that there may be nothing I can do to save my wife, even though I will do my damn hardest to do so .

"I am going to try and put an end to this global epidemic. I am now facing one of my biggest personal challenges of my life and will make sure that, whilst I am still on this Earth, I put all my efforts in finding a cure for this horrendous illness. I want to make sure I can do all I can to help millions of people around the world avoid this heartache.”

Race Against Dementia is aiming to raise millions of pounds from donations to fund global research into a cure for the condition, and is backed by a number of wealthy trustees.

It will help fund research into the identification and development of new drugs to treat dementia, as well as other studies of the disease.

Hilary Evans, Chief Executive of Alzheimer’s Research UK says, “Sir Jackie’s vision is driven by pure determination and ultimately, love. Dementia has such a high prevalence globally and it is often thought of as an inevitable part of getting older but this is simply not the case – the condition is caused by brain diseases that we can slow or stop through research. Researchers are working extremely hard to find new treatments and we are delighted to be part of this unique and innovative approach to accelerate global research efforts.”