By Carol A. Kemper, MD, FACP
Clinical Associate Professor of Medicine, Stanford University, Division of Infectious Diseases, Santa Clara Valley Medical Center
Dr. Kemper reports no financial relationships relevant to this field of study.
The ecorevolution has spawned some interesting theories and crazy ideas. Not only is there the paleo diet, but also paleo bathing — or, rather, non-bathing. Concerns have been raised that soaps are harmful to the skin, its natural odors, and its natural microbiome, leaving skin open to diseases such as acne, eczema, and even bacterial superinfection. Indeed, certain soaps — and the overuse of hot water — can lead to dry skin and alter its pH.
Not only are a growing number of people forgoing deodorants and soaps, some have gone from washing once a day to once a week or have stopped bathing altogether. Several companies are answering the call for “natural” skin care products intended to restore the normal skin oils and bacteria, including a burgeoning probiotic skin care industry. One French company uses heat-deactivated lactobacillus in a lotion, while another U.S.-based company suspends microorganisms in a gel product.
After watching horses rolling in the dirt, one inventor harvested dirt samples from a local farm, attempted to analyze their function, and concluded that certain strains of bacteria that convert ammonia to nitrogen are necessary for maintaining a pleasant body odor. He created a “Motherdirt” mist spray containing a designated strain of ammonia-oxidizing bacteria to restore natural body odor. Now, there are even “prebiotics,” which are intended to nurture the skin’s existing microbes.
What is interesting is that many of these nonbathers claim they do not smell. However, our brains literally filter out our own body’s odors and its byproducts. That is why the bathroom always smells worse after someone else uses it. Of course, these nonbathers emit an odor; they just do not smell it themselves.
It is true that many mammals and birds survive without a hot shower and instead take “dust baths,” the purpose of which has been debated for years. Studies suggest these may be one way to thermoregulate or rid the body of ectoparasites by literally knocking them off or smothering them with dust. Birds may use dust or dirt baths to remove excess oils from feathers so that they are fluffier and provide better insulation. But after watching my chickens roll around in the dirt, I can testify that they are not any cleaner, and they most certainly smell.
Although showering with hot water and harsh soap daily may not be optimal, studies have shown that regular bathing with good soap and water reduces the risk of infection in individuals colonized with Staphylococcus aureus. I routinely advise daily baths with a good lye-based soap, a clean washcloth, and lots of sudsing, especially to those areas where bacteria accumulate (axilla, perineum, groin, gluteal crease). With simple hygienic measures and freshly laundered clothing, many patients with methicillin-susceptible S. aureus or methicillin-resistant S. aureus folliculitis or boils improve. Besides, showers are one of the clear pleasures of the modern world. As the fictional time-traveling Claire Fraser of the Outlander series says, in choosing between the attractions of her 23-year-old husband in the 18th century and the benefits of living in the 20th century, hot showers almost won.