Angela Rippon's mother Edna died from dementia six years ago, and the former newsreader has revealed to What's on TV that developing the disease herself is her biggest fear.
In a new documentary for BBC1, Angela undergoes various tests to see if she is at risk.
"Until you come face to face with dementia and a loved one is affected by it, it’s not on your radar," says Angela, 71. ‘But it can be so lonely and isolating, both as a sufferer and carer.
"Mum became short-tempered, rude and very difficult at times. She lived in a parallel universe where she believed her mother and brother were still alive.
"She’d say things like, ‘your Uncle Alfred came to see me today – he’s such a snappy dresser.’ But he died when I was 12. It’s so hard to watch your loved one gradually slip away like that."
Dementia affects 850,000 people in the UK and that number is set to double in the next 10 years. In the documentary, Angela explores the latest scientific research into the disease that could one day provide a cure, visits a brain bank where she witnesses the shocking physical effects of dementia on a real human brain, and discovers how learning a language is better than any pill in preventing the disease.
She also has a cognitive test - a series of questions to test her memory - which is how her mum was diagnosed with dementia, a full brain scan to determine whether she’s showing any early signs of the disease, and a genetic blood test to assess her future risk of developing it.
"I’m not nervous about the results," says Angela. "I’ll just have to deal with the outcome and I’d rather know than not. If I know what to expect, then at least I can plan for it."
In the meantime, Angela is keen to keep her brain as active as possible.
"I’m determined to do whatever I can to do to keep my brain healthy. I speak French, do jigsaws and Sudoku, and my job as a journalist keeps my brain busy," she said. "I just hope one day there’ll be a cure for dementia – I’d love to see it in my lifetime."
The Truth About Dementia screens on BBC1 on Thursday, May 19 at 9pm
