The 49-year-old TV presenter revealed her fears about developing Alzheimer's disease, the condition that both her father and grandmother have lived with.
"I have called my doctor twice in floods of tears saying ‘I've definitely got it'," McCall said in a new interview with Good Housekeeping.
"She told me ‘If you had Alzheimer's you wouldn't be calling me about it'."
She added: "I don't drink, don't smoke and I'm in good health. If I get ill, I get ill - it's a lottery."
McCall recently opened up about her dad's Alzheimer's disease on John Bishop's John Bishop: In Conversation With, describing her father's diagnosis as "terribly frightening".
is still Andrew," she said. "He's still out there; he's still having a
good time; he's had a diagnosis that would stop a lot of people in their
tracks and make them want to give up on life, but he hasn't let it do
"And he's such an inspiration and I hope with anybody else
that gets this terrible, terribly frightening diagnosis and really
terrifying if you, you know, God, if you Google Alzheimer's it's just
darkness, you know, it's terrible."
"But I look at my Dad and I see such hope and, um, such positivity and each hurdle we'll cross when we get to it."
In the same interview, McCall also recalled the moment that made her take action against her drug addiction.
McCall is undoubtedly a beacon of health and happiness, with a successful career as a TV presenter as well as her own clothing range, fitness DVDS and recipe books. But in her late teens and early 20s, the star battled with heroin addiction. At the height of her problem Davina had gone £3,000 overdrawn to fund her habit and slept on a camp bed in the cupboard of her father's house.
Speaking to Bishop, McCall remembered how a friend's tough love spurred her into action to battle her addiction.
"I'd lost all the good people," she said. "There was one person left, and she was the one that said to me in the end, 'Look, we're all talking about you. You think you've got this kind of mask up and you're kidding us all, but you're not.'"
"‘We all know that you're a junkie and we all know you're taking heroin or we all know that you're, you know, you're lying to us the whole time. And I'm not going to stand around and watch it anymore.'"
"She said, 'I've had enough.' And she'd been so there for me the whole time, I just thought she was going to be the one constant. And when she said, 'That's it,' I was devastated. Course, I swore at her a lot and got out the car, slammed the door!"