Quick one: Is not bathing actually good for your skin?

Not too long ago, a group of celebrities sparked a debate about how much you really need to bathe.

It began innocently enough with Mila Kunis and Ashton Kutcher telling Dax Shepard and Monica Padman on the podcast, Armchair Expert, that they only wash their children "if you can see the dirt on them. Otherwise, there's no point."

Kutcher then added: "I wash my armpits and my crotch daily, and nothing else ever."

Watch: Seven ways to improve your skin while sleeping. Post continues after video.

Then Dax Shepard and Kristen Bell agreed, with Bell telling The View, "I'm a big fan of waiting for the stink. Once we catch a whiff, that’s biology’s way of letting you know you need to clean it up."

Oh, but we're not done. Then Jake Gyllenhaal weighed in and took it one step further, suggesting that bathing less is actually better for the skin.

"There's a whole world of not bathing that is really helpful for skin maintenance, and we naturally clean ourselves," he told Vanity Fair.

Whilst we know showering or taking a bath every day is a privilege, it's a habit to which most of us are accustomed.

But when it comes to full-body cleansing, do these celebrities have a point? Do we *really* need to shower every day?

Medical and cosmetic dermatologist Dr Katherine Armour explained that how often you shower or take a bath is really up to you.

"There is no set number for how often we should be bathing, and much like the skincare for our face, individual circumstances need to be considered," she told Mamamia.

"The 'right' showering frequency varies from person to person. If you do a physical job or exercise regularly, you’ll need to bathe more frequently than someone who is more sedentary.

"How often we bathe is really a personal choice."

And it seems Ashton Kutcher might be onto something...

"It isn't necessary to lather your entire body with soap/soap-free wash daily," Dr Armour continued.

"To avoid body odour, cleansing your armpits, groin and buttocks is sufficient."

Image: Getty. 

Dr Armour explained the only risk associated with not showering is, well, smelling. So, as children don't start having issues with body odour until puberty, they can go longer without bathing.

"At the very least, children should bathe once to twice a week. This should be more often if they get dirty during outside play or fun activities such as playing with paint," she said.

"It is also important to bathe on the same day if children swim in a pool, sea or other body of water. Chlorine, in particular, is very drying and irritating if left on the skin."

Listen to Mamamia's podcast for your face, You Beauty. Post continues after audio.

But sorry, Jake Gyllenhaal, there's no evidence to suggest not bathing is actually beneficial for the skin.

"This statement is interesting, but it’s not evidence-based," Dr Armour said.

"Whilst bathing itself doesn’t damage the skin, some bathing habits can be troublesome for those who have sensitive or dry skin," she said.

"Long, hot showers can wreak havoc on your lipid barrier (the fatty outer layer that keeps moisture in and infection/irritants out) and strip your skin of its natural oils, leading to dry and cracked skin and increasing the risk of infection," she said.

"Try to keep showers short — preferably under three minutes in length — and at a lukewarm to warm temperature.

Of course, minimising your water use with a shorter shower sesh is better for the environment, too.

"[And] avoid being squeaky clean. Soaps are alkaline and can dissolve the skin barrier. The skin surface is meant to be quite acidic and good bacteria enjoy an acidic skin environment.

"Using soap substitutes or soap-free washes is another way to safely shower daily, whilst avoiding the irritation that soaps can cause," she added.

Well, there you have it.

These celebs skipping their daily showers might not be bonkers after all.

Feature image: Getty.