Meet Your Invisible Allies: Exploring the Skin Microbiome & Redefining Cleanliness
Our skin is our largest organ. If it were laid out flat, our skin would be about 20 square feet.
Our skin provides us with environmental feedback, protects us from pathogens, and helps us regulate temperature.
Trillions of microbes live on our skin. Approximately 1 billion bacteria are found in 1 sq cm of skin.
Most are not only harmless, but they benefit our skin and our immune system.
Our sweat includes dermicidin, cathelicidin, and lactoferrin, substances that help maintain microbial balance.
In a study on mice, half the mice were covered with Staphylococcus epidermidis, a bacteria commonly found on human skin, and half the mice were not. Both groups were exposed to the sun. Those covered with the bacteria had lower rates of skin cancer than those that did not.
This effect is thought to be because the bacteria makes 6-N-hydroxyaminopurine that attacks tumor cells, keeping tumor DNA from replicating.
Despite its high visibility, most of us probably don’t often think about how important our skin and the trillions of microbes on its surface area are to our survival unless it gets damaged. We may, however, think about how our skin appears or whether it appears clean or not.
I certainly didn’t give much thought to my skin and what being clean actually meant until I read the book “Clean: The New Science of Skin and the Beauty of Doing Less” by James Hamblin MD a couple of years ago. Throughout his book, Hamblin challenges what it truly means to be clean and what we really need to do to care for our skin.
Through challenging notions of cleanliness and weaving together scientific insights, historical perspectives, and cultural influences we can take a more mindful approach to skincare that considers the symbiotic relationship between the skin microbiome, personal health, and the environment.
Humans used to clean ourselves by sporatically taking a dip in a rivers or lakes like this one in the North Cascades. Now many of us shower daily.
The Evolution of Cleanliness
Historically, people spent most of their time outdoors. Feelings of disgust towards things that could cause us disease are found around the world. This is an evolutionary advantage and is even found in other species. However, our skin evolved surrounded by dirt, plants, and animals, which are full of microbes, a far cry from our mostly indoor environments today. We used to take a dip in a river or lake sporadically to clean ourselves, now many of us shower daily. Interestingly, ancient Judaic, Islamic, and Hindi teachings emphasize the need for hygienic practices, such as handwashing, unlike Christianity which explains why the Middle Ages in Europe is known for its lack of hygiene.
In 1854, during a cholera outbreak in London, John Snow discovered the disease was caused by contaminated water. In 1884 Robert Koch saw Vibrio cholerae under a microscope which led to “germ theory”. It didn’t take long after that for hygiene to become a status symbol. The working class were called the “great unwashed”. Sadly, germ theory also gave rise to the eugenics and isolationist movements in the late 19th century.
When running water and bathtubs became more common, the working class started bathing. Suddenly the wealthy needed new ways to set themselves apart. Capitalism provided that to them in the form of new skincare products. Because most soap is very similar chemically, soap companies became experts at marketing to specific desires and demographics. Soap operas were some of the first sponsored content as they were funded by soap companies finding new ways to sell their goods. The soap, detergent, deodorant, hair, and skincare product market is now valued in the trillions of dollars. Today these products are marketed as a necessity, not a luxury. High priced versions of these goods are now the luxury status-symbol option.
In our modern world, hygiene is associated with avoiding disease, but cleanliness often goes beyond that.
Our skin evolved surrounded by dirt, sand, plants, and animals, which are full of microbes, a far cry from our mostly indoor environments today.
Understanding Soap
Humans have used soap all across the globe for much of recorded history. Only recently have people used it everyday, and not just because they want to, but because they feel a necessity to do so. According to Hamblin, if you spend 30 minutes per day showering and applying skincare products and you live to be 100 years old, you’ll spend 18,250 hours washing during your life.
Soaps and detergents remove the oils on our skin that our microbes feed on. Hot water also strips away our own oils (I’m sad too, I love a really hot shower), leaving the skin more vulnerable to irritants and providing an entryway to pathogens. After we are sold soap, which strips away our own oils, we are then sold moisturizers to replenish what we stripped away with soap.
I don’t state these facts to say we should never wash ourselves again. Handwashing is one of the most effective ways to avoid falling ill and spreading pathogens. Many grooming practices are cultural and people obtain pleasure from these rituals. Some products may help our skin feel and look better, increasing self-confidence. However, I am challenging you to think about what you put on your skin and what is really necessary to feel clean. Sometimes less is more.
Early research suggests decreased asthma & allergy rates among children growing up on farms compared to children growing up in urban areas.
The Skin Microbiome
Most of us have heard about the gut microbiome by now, but perhaps not the skin microbiome. Emerging research suggests healthy skin microbes may play a role in preventing allergies and immune-modulated diseases. A child’s microbiome is established at around 4 years old.
Early research is finding decreased asthma and allergy rates among children growing up on farms compared to children growing up in urban or suburban areas.
Amish communities who spend considerably more time outside than the rest of the US have lower asthma and allergy rates.
In one study, mice were exposed to house dust from typical American homes and from Amish homes. The mice exposed to Amish home dust were found to have decreased amounts of cells associated with allergies and had airways that were less reactive.
Children with older siblings, who carry a plethora of microbes, are less likely to develop eczema and hay fever than children without older siblings.
One theory explaining this “hygiene hypothesis” effect is the idea that early microbial exposures train our immune system to react appropriately with a sufficient inflammatory response to invading pathogens. Without proper early microbial exposure, our immune systems attack our bodies instead, contributing to unnecessary inflammation, allergies, and autoimmune diseases. Of course there are many factors that cause these conditions but a study in mice suggests how early exposure benefits the immune system.
Researchers exposed half the mice to Staphylococcus epidermidis the first week they were born while the other half was not.
The mice that were exposed had regulatory T cells that recognized S. epidermidis when they were exposed later in life whereas the unexposed mice developed an allergic reaction toward the bacteria.
This suggests that eventually scientists may be able to use beneficial bacteria to treat conditions caused by harmful bacteria.
Washing away microbes on our skin creates more space for opportunistic pathogens to take hold. This information is not to be construed to mean we shouldn’t clean ourselves, but it does challenge us to create an appropriate balance between hygienic practices and exposure to microbes.
Playing in the dirt may not come as naturally to us as adults as it does children, but microbes from the dirt may benefit our skin and immune system.
Personal Care Product Industry (Lack of) Regulation
Personal care products are NOT legally considered drugs or food which means there is very little gatekeeping behind getting products on the market.
Companies can market with terminology that suggests a product can improve your health without jumping through the regulations it takes to get a drug on the market.
In the United States, there are only 11 substances that are banned or restricted from being added to skincare products. So scary!
In comparison, the European Union has banned 1500 substances and Canada has restricted 800 substances.
Personal care products have been found to contain lead, mercury, formaldehyde, asbestos, PFAS, phthalates, parabens, and more. Many of these substances are known or potential carcinogens and endocrine disruptors.
Currently, personal care products fall under Consumer Product Safety Commission regulation. This means that products are only reviewed retroactively after harm has occurred, instead of before products reach the market. Additionally, terms such as “natural”, “clean”, and “non-toxic” are not regulated.
Before the “Modernization of Cosmetics Regulation Act of 2022” (MoCRA), no federal law regulating personal care products in the U.S. had been updated since the Federal Food, Drug, and Cosmetic Act of 1938!
MoCRA mandates that manufacturers report adverse health events associated with their products and allows the FDA to recall products if companies do not voluntarily do so among other requirements.
While MoCRA is a step in the right direction it still does not outright ban harmful ingredients.
These unregulated ingredients also end up in our waterways when we wash off products, negatively impacting aquatic life and can end up in our soil.
Spending time outdoors exposes us to beneficial microbes. Just don’t forget to wash your hands before you cook or eat!
Caring for Your Skin
Given this information, it’s easy to feel overwhelmed about what is actually safe to use and what we should be putting on our skin. I’m not here to tell you what products you should or shouldn’t use but I do have a few tips.
Simple is better
The fewer products we use on our skin the less we disturb our microbial balance and skin pH which protect us against invading pathogens.
For example, consider showering every other day instead of every day. Or only regularly using soap on the parts of your body that may stink if you don’t.
You may need to be patient as your skin adjusts to less.
There is privilege that comes with even considering to use less products or showering less often. Sadly, in our society appearance can change how people are treated or cause them to be treated with less respect.
And people in many areas of the world lack access to basic soap to wash their hands. Just like our food system, there is a gross imbalance in who has access to hygiene products. As Hamblin states, “Parts of the world are in desperate need of basic sanitation and hygiene, food and water, while others have hoarded resources to their own detriment.”
Get outside and play in the dirt.
Garden, exercise outdoors, play with your dog outside. Click here for more ideas.
But also wash your hands, especially before you cook or eat.
Consult the Environmental Working Group (EWG) Skin Deep Database
The EWG is a nonprofit that researches and maintains a database of products and ingredients with health and environmental ratings.
Check out what your current products are rated or use it to find safer products.
While we don’t yet know the exact percentage of specific substances our skin absorbs, our skin is porous and does connect to our bloodstream. I don’t know about you but I would rather not be slathering myself in potentially harmful substances that could be absorbed and distributed all around my body.
Care for your skin from the inside out
All of our body systems are connected. Sleep, nutrition, hydration, etc. can all impact the health of our skin.
High insulin levels can cause your body to turn estrogen into testosterone. Then, testosterone promotes more oil secretion on the skin.
Early research suggests dietary vitamin C helps promote skin collagen synthesis and is more easily absorbed than topical vitamin C.
Vitamin C and E are associated with protecting against UV damage.
Dietary protein and vitamin C are known to promote wound healing.
Eating fresh vegetables and fruit expose us to more microbes than prepackaged foods.
Eating fresh fruit and veggies expose us to more microbes than prepackaged foods and contain vitamins that protect our skin.
While the science is young, it appears our skin microbiome plays a large role in our health and is worth protecting. I am absolutely not suggesting we give up bathing ourselves. There can be a profound ritual in washing ourselves. Handwashing is the most effective tool against infectious disease. Most of us probably don’t want to smell bad. But there can be too much of a good thing.
It’s crucial to be mindful of the impact of personal care products on our health and the environment. Simple practices, like consulting resources such as the Environmental Working Group (EWG) Skin Deep Database, empower us to make more informed choices. Embracing a less-is-more approach allows us to strike a balance between hygiene and the well-being of our skin microbiome as we respect a balance between modern practices and evolutionary wisdom.
Have you considered the historical and cultural influences on our perceptions of cleanliness? Do you think about the ingredients in your skincare products and their impact on the environment and your skin's health? How can you balance modern hygiene practices with a timeless connection to nature for your skin microbiome and overall well-being?
Sources
Environmental Working Group (n.d.). Your guide to safer personal care products. EWG’s Skin Deep. https://www.ewg.org/skindeep/
Healthwise Staff (2023, March 21). High-protein foods for wound healing. Kaiser Permanente. https://healthy.kaiserpermanente.org/health-wellness/health-encyclopedia/he.high-protein-foods-for-wound-healing.abs1199
Hamblin, J. (2021). Clean: The new science of skin and the beauty of doing less. Penguin Random House.
Kuya, J., Omoronyia, O., Fokukora, T., Emmanuel, A. P., Ewemooje, O. S., Soyege, A. O., Ngo, V., Anyiam, F. E., Ackah, J. A., Ossai-Chidi, L., Manuel, B., Okondu, O. E., & Nwaru, B. I. (2021). Farm living and risk of asthma, atopic eczema, respiratory and food allergy: protocol for a systematic review and meta-analysis. BMJ Open, 11(12), e048736. https://doi.org/10.1136/bmjopen-2021-048736
McConnell, J. (2023, January 19). Modernization of cosmetics regulation act of 2022: MOCRA explained. Women’s Voices for the Earth. https://womensvoices.org/2023/01/19/modernization-of-cosmetics-regulation-act-of-2022-mocra-explained/
Pullar, J. M., Carr, A. C., & Vissers, M. C. M. (2017). The Roles of Vitamin C in Skin Health. Nutrients, 9(8), 866. https://doi.org/10.3390/nu9080866
Sheikh, K. (2023, Feb 15). Many personal care products contain harmful chemicals. Here’s what to do about it. The New York Times. https://www.nytimes.com/2023/02/15/well/live/personal-care-products-chemicals.html
U.S. Food and Drug Administration (2023, Nov 8). Modernization of cosmetics regulation act of 2022 (MoCRA). https://www.fda.gov/cosmetics/cosmetics-laws-regulations/modernization-cosmetics-regulation-act-2022-mocra
