SIR Jackie Stewart has spoken of how his wife’s dementia diagnosis inspired him to start a race against the devastating disease.

In an interview with former First Minister Alex Salmond, the Formula 1 legend said he hoped to make a breakthrough in the fight against the condition.

Dumbarton-born Jackie’s wife Helen, 75, was diagnosed with dementia four years ago, affecting her memory and mobility.

In response he set up a foundation - Race Against Dementia - and now hopes to combine the talents of top medical research facilities at Harvard and the Mayo Clinic in a bid to defeat the illness.

Speaking on The Alex Salmond Show broadcast on RT, he said: “Dementia has no cure currently, and has no preventative medicine to stop people from having dementia.

“Helen’s short-term memory now is very, very weak. Sometimes she doesn’t know whether she’s in Switzerland or England.

“It’s a terrible disease for many people – and what a terrible cost it is for a family, to see one of their own not being able to be cared for, because there’s no money left in the kitty for them to be looked after.

“Helen’s looked after by two neuro nurses. It costs a huge amount of money. I can afford that, but very few other people can.”

Sir Jackie, 78, also spoke of his campaign for better safety in Grand Prix racing and his life-long struggle with dyslexia.

He said the shame and humiliation of being unable to read or write almost cost him his life chances, and insisted his dyslexia diagnosis in his early 40s was "as if I had been saved from drowning".