The duo were let go from the ITV1 lunchtime panel show at the end of the last series earlier this month. The programme will return from its summer break with new faces Carol Vorderman and Sally Lindsay.
Hewson told The Mirror: "OK, of course it's sad for Zoe and Kate personally. But these things happen every day in television. It's never personal, although of course it feels that way when it's happening to you and it's a job you love.
"The truth is, shows change all the time and executives want to renew and re-energise them. It's awful news for the girls themselves, but unfortunately it happens to everyone in TV at some point and it doesn't mean the end of you."
Hewson continued: "Coleen Nolan was axed along with Twiggy from This Morning ten years ago and look at her now - she's back on the same show and more popular than ever."
The 60-year-old said that there is "nothing you can do about it" when someone decides that "they want to shake things up".
"Kate was back on primetime TV the other night presenting the Will Young special and Zoe is already on tour, so they are back in business and doing great," she said. "We made sure we gave them a proper send-off in the usual Loose Women tradition - we all went out and got drunk!"
Speaking about her new co-panellists, the actress said that both Vorderman and Lindsay "will be great".
"They are both lovely, and the more different opinions we have on the show the better - fresh blood keeps things interesting. Loose Women is a very even ship. There is no room for big egos or dramatics," she said. "The rest of us will just get back on set and get on with our usual stuff and they'll slot in with us like old friends.
"They've both been in as guests before so it's not like they've never met any of us. And Sally especially is another ex-Corrie girl, so she'll be familiar company with me and Denise. We can't wait to hear what they've got to say - the more opinions the merrier."
It was announced last week that Hewson has joined the cast of ITV1 comedy Benidorm.
> Kate Thornton 'at peace' with Loose Women exit
> Zoe Tyler 'shocked' over Loose Women axe
Watch Kate Thornton say goodbye to Loose Women below: