Katherine Ryan is known for being both honest and hilarious, speaking openly about everything from her post pregnancy facelift, to the candid reality of parenting four children.
However, when a blood test revealed her true biological age, Katherine still responded with some of her usual humour but was also quite "hurt" by the results.
The comedian has a podcast called What's My Age Again?, that involves celebrity guests undergoing tests to calculate their true biological age based on the condition of their cells and bodily tissue.
When their age is revealed, the guests chat to Katherine about longevity, what the results mean to them and how they feel about ageing.
When Katherine took the test herself, she was shocked to find her biological age was higher than her chronological age than any guest that had ever appeared on the podcast.
Speaking on the April 4 episode of The Jonathan Ross Show, Katherine shares what happened when she got her results.
"Brace yourself, it was hurtful," she says, adding, "I’m 42, my biological age is 77. It’s almost over for me…"
However, Katherine does suffer from the autoimmune disease lupus, where the immune system attacks healthy tissues in the body, causing inflammation and potential damage to joints, skin, and organs.
This could have impacted her results and she had medical advice about what she could do to bring her biological down to be more in line with her real age.
"There are a lot of really cool takeaways on the podcast," Katherine says on Jonathan's chat show, continuing, "Cold plunges are really effective… I am taking magnesium now. I eat 30 plants a week."
The comedian later had a follow up test to see if her biological age had come down.
The star recently updated fans with a special episode of the podcast revealing her updated biological age, and it had reduced to 57.
Dr Chris Wincup, a consultant rheumatologist at King’s College hospital joined Katherine for the update, suggesting her fourth pregnancy might've impacted the results.
Dr Wincup explains that when a person has lupus, their immune system is overactive, and "goes after" the person, instead of things that shouldn't be in their body.
"When you're pregnant you start to grow something that is a bit like you but not completely like you, so the immune system has to shut itself off a bit for the sake of the baby," he explains.
He adds, "There is some suggestions that as that happens, the immune system starts to quiet down and if you've got an autoimmune condition, maybe that starts to quiet down as well."
"I mean, it is still high though," Katherine says of her readjusted age, referring to the biological age of 57 as "still bad."
While no definitive reason was given for why it had come down from 77 to 57 was offered, Dr Wincup reiterated it was likely to be her pregnancy that helped her body make the reduction.
The Jonathan Ross Show airs on Saturdays at 10pm on ITV1 and ITVX.
