Richard Madeley joked that he might start taking HRT after Jan Leeming claimed that's what keeps her feeling and looking so good for her age.
The TV presenter and newsreader appeared on Wednesday's Good Morning Britain to discuss a recent mugging in France which left her with a six inch gash on her arm.
Jan, who appeared in I'm A Celebrity... Get Me Out of Here! says she was "rugby tackled" to the ground by a masked man in ''sleepy little village'' in France.
Jan said she had been using an ATM when a man offered to shake her hand and she was thrown to the floor.
The TV star branded herself a 'first rate idiot' for accepting the man's hand as she told how she'd been left with a six inch cut to her arm.
Speaking during the interview, host Richard Madeley said: "You've told our researchers you're more than happy for us to say how old you are," as Jan confirmed: "Yes!"
Richard continued: "And I find this... I almost think you're winding us up... you're 80!
"And what's significant about that and the way you look - which is incredible - and the fact that you didn't break any bones... you hit the ground hard, I mean this was a proper rugby tackle. You put it down to HRT don't you?"
Jan replied: "Well, HRT, good diet, never having taken drugs or smoked, but mostly HRT. I've been on it since 47. And every year the doctor, I suppose you'd say legally, has to warn you about the possibility of breast cancer.
"So every year I say, 'thank you very much doctor but quality of life...' I have tried everything you can think of and it's never worked so I have stayed on HRT, my bone density for my age is good.
"It's my choice and every year when I have to have this meeting with my doctor I just say, 'Look I choose my quality of life'," Jan added.
"Anyway, it's great to see you looking so well and so philosophical about something which a lot of people would find hard to get over," Richard said as Kate Garraway added: "It's a great poster campaign for HRT, we'll all be talking to her in a minute!"
Father-of-two Richard then joked: "I might take some!" as Kate and Jan laughed.
GMB viewers were also stunned by Jan's age and took to Twitter to comment.
One person tweeted: "#GMB jan looks amazing for 80," while another said: "Jan leeming 80, looks fantastic . #GMB."
A third person posted: "This lady looks so elegant and it’s refreshing to see an older woman who hasn’t got a face filled with Botox and filler. I’d be happy to have a face like hers at 65 let alone 80 #GMB."
Good Morning Britain airs weekdays at 6am on ITV and ITV Hub.
