How often should you shower? Advice from a doctor who bucked social norms

Our skin is considered our largest organ, with a surface area of approximately 15 to 20 square feet (1.4 to 1.9 square meters) — and some put the estimate at least 10 times greater, if the nooks and crannies created by hair follicles and sweat ducts are taken into consideration. It is our body's first line of defense, charged with (among other things) keeping the outside out and our insides in.

And we like to keep our skin squeaky clean, especially in the United States. The beauty and personal care products market (which includes skin, hair, mouth, shower and bath, cosmetics, and fragrance products) in the US amounted to more than $100 billion in 2024, and it's projected to keep growing.

"You walk into any pharmacy and next to cold and flu medications, there are aisles of shampoos and soaps. It just got me thinking: what is this all for?" Dr. James Hamblin told CNN Chief Medical Correspondent Dr. Sanjay Gupta on his podcast Chasing Life recently.

Those were all questions Hamblin, a preventive medicine and public health doctor and then a writer for The Atlantic, wanted to explore. So he stopped showering — in the traditional sense of the word — for about five years. (Before you click out of the story in horror, please read on.)

Hamblin's 2020 book "Clean, The New Science of Skin" documents his experiment and traces the history of cleanliness and hygiene.

"I carefully wrote (in the book) that five years ago I stopped — and I did," he explained, noting that those years were dedicated to trial and error. "In that time …. I tried all kinds of different products. This was a course of experimentation of all different sorts of regimens. So, I didn't spend five entire years never showering — no. But people really wanted to hear that."

But, he said, "I certainly was very minimalist for a very long time."

Hamblin, who is now a lecturer at the Yale School of Public Health, said there is "a large health halo" around personal care products. We think of them as hygiene-promoting because many make medical-sounding claims, which amount only to clever marketing.

"If you look at the actual way in which many of those products are actually doing anything to prevent disease transmission (besides) making sure you don't have bodily fluids on you … that might transmit disease, the rest of it is making you look and feel and smell good."

Soap is a valuable tool, he said, mainly to help break up sticky, oily substances. "But usually, it's more the mechanical force that's doing most of the washing," he said. "When you rub your hands together … under water, you're getting a lot of that off." (To be clear, we are talking about in most situations, and not in the case of food workers or surgeons trying to get sterile for surgery, for example.)

Hamblin said he was inspired to write his book in part because of a fairly new health trend at the time.

"People were suddenly taking probiotics and wanting to have optimal gut flora," he said. "And I saw the same thing potentially happening in skin health because you have these trillions of microbes all over you. The skin microbiome is smaller than the gut microbiome, but it's a similar principle."

An abundant and diverse microbial community lives on our skin, just like in our gut. The skin microbiome is a go-between, interacting with both our body's internal world and the external world. The results of these interactions impact our individual health in ways we are only just beginning to understand. Constantly washing it away can create issues.

"There is a harmony between the oils and chemicals that your skin secretes naturally and the skin microbiome that lives on that skin," he explained. "You temporarily disrupt the microbiome when you take a hot shower, and you use (soap). But you're also disrupting essentially the soil on which those microbes live, by drying out your skin and removing all the oils."

It's not necessarily bad, he said, "but it changes the dynamic. And if you are prone to an inflammatory cascade like (what) happens with eczema or acne, you can be exacerbating (that problem)." He likened it to clear-cutting of a forest, which isn't always good for the land.

"We don't know any more than we really do with the gut microbiome," he said. "It's not so simple as saying, 'Well, you have taken out this one microbe; we're going to put this one microbe back in, or we're going to replace it with this other one, and you will feel all better.' It's much more of a holistic ecosystem that is difficult to understand."

From : CNN