Celebrities have been sharing some dirty secrets – about their own hygiene habits.

It all started when Ashton Kutcher and Mila Kunis confessed that they don’t bathe daily. The pair told the Armchair Expert podcast that other than washing important parts of their bodies, they don’t shower every day, and this approach is something they’ve extended to their children.

Kunis told host Dax Shepard: “I don’t wash my body with soap every day. I wash pits and t*** and holes and soles… When I had children, I also didn’t wash them every day. I wasn’t the parent that bathed my newborns – ever.”

Kutcher agreed by saying: “If you can see the dirt on them, clean them. Otherwise, there’s no point.”

Other celebs soon joined the debate, with Jake Gyllenhaal admitting: “More and more I find bathing to be less necessary.” But we all breathed a sigh of relief, when Dwayne “The Rock” Johnson reassured us showering is still cool, telling fans: “I’m the opposite of a ‘not washing themselves’ celeb.”

Their antics have sparked an online debate about hygiene and whether we should be taking a shower every single day. Considering the past year has focused on staying clean and trying not to get Covid-19, we asked a leading expert how much washing is enough.

Professor Sally Bloomfield from the London School of Hygiene and Tropical Medicine actually agrees with Kunis and Kutcher. “I think it’s important that we don’t wash every single day,” she tells HuffPost UK.

“The skin is our barrier and it’s evolved and developed to have properties that sustain that barrier function, against the ingress of disease and toxins and so forth so it wasn’t developed to be washed every day.”

Washing our skin every day can wash off natural oils and upset the natural balance and the essential properties of the skin, Bloomfield adds. She knows bathing is a source of personal comfort, but doesn’t see washing every day as necessary.

Similar to Kutcher and Kunis, Bloomfield thinks we should be washing specific parts of our body every day. “Most of our body odours come either from the armpits or the anal area and they can be quite well controlled by washing those sensitive areas daily without having to bathe the whole body,” she says. “If it’s very hot and you’re sweating, then you will want to rinse off the salts and make yourself feel comfortable again. Obviously, personal hygiene is important for controlling odour.”

How about it when it comes to preventing diseases such as Covid-19? Since Covid is an airborne transmitted disease, Bloomfield says you don’t need to wash your entire body, only your hands. “It’s controlled by good hand hygiene and hand contact hygiene. You’re only getting it on your hands, you’re not getting on your whole body. There’s no point in washing your whole body because the risks of transmission via your body are very, very small, all you need to do to prevent transmission of infection, is by keeping it off your hands and prevent your self-touching.”

The only way we get some infections is by touching our mouth, nose, and face. Other infections are caught by a breakdown in the body such as cuts or grazes. So overall, Bloomfield doesn’t see any health benefits to having a daily shower.

Those are the facts, but we won’t be ditching bath time just yet. Sorry, Dr Bloomfield.