Science has shown that the trillions of bacteria living inside our bodies play an important role in supporting our immune system and maintaining our physical well-being.
But what about the other trillions of bacteria, archaea, fungi, parasites and yes, viruses, taking up residence outside of our bodies on our skin? Do these microorganisms also play an important role in maintaining our health? Or - as the $100 billion personal care industry would lead us to believe - are they notorious germs that must be scrubbed off daily to satisfy a socially appropriate level of clean?
Yale School of Public Health Lecturer Dr. James Hamblin does his best to address those questions in his new book Clean – The New Science of Skin and the Beauty of Doing Less (Riverhead, 2020, 280 pages). Hamblin, MPH ’18, is a preventive medicine specialist, staff writer for The Atlantic, and podcast host whose work has been featured in the New York Times and on NPR, PBS, Politico, MSNBC, the BBC and Vice.
The book is the result of five years of deep research that took Hamblin on a journey through soap factories, microbiology labs and the Manhattan offices of one of the world’s most popular high-end skin care companies. Along the way he talked to dermatologists, allergists, immunologist, aestheticians, Amish people, theologians and even scam artists. Hamblin spends considerable time in the book explaining the history, science and socio-cultural factors associated with cleanliness from Roman baths and germ theory to the value of popular modern-day skin care products like “Glass Skin Refining Serum” and “Matcha Pudding Antioxidant Cream.” In presenting the facts, Hamblin remains neutral. Like personal nutrition, financial investments or religion, what people ultimately choose to do is their decision, he says.
As part of his research, Hamblin stopped showering five years ago. He wanted to see first-hand how his body changed as he gradually tapered off a daily dose of shampoos, conditioners, soaps, exfoliants, deodorants and moisturizers. As a doctor, Hamblin stresses that good personal hygiene is absolutely necessary in preventing illness and disease. He never stopped washing his hands. He still wets his hair occasionally, but that’s pretty much it.
So, what did he learn and what does he want the rest of us to know? Hamblin recently took a few minutes to talk about his experience and his research.
What got you interested in exploring cleanliness and the science of skin?
JH: It was a confluence of things, really. I saw the potential for a reconceptualization of how we think about our skin and hygiene practices like we see happening with the gut microbiome. People have become less cavalier about antibiotic use because of what we now know about the gut microbiome and they are embracing the fact that the microorganisms in our gut matter clinically. They have so many effects on our health and how our bodies function. About the same time, I was seeing papers come out about the skin microbiome and was curious whether something similar was going to happen in terms of altering our long-standing idea that being clean simply means eradicating all the microbes from your body, which is clearly not the case. You always have microbes all over you, even right after you hop out of the shower. So, it makes you wonder what the most effective public health intervention is when it comes to these skin microbes and what is just sort of hygiene theater.
Are there microbes on our skin that play an important function in maintaining our health?
JH: Like the gut microbiome, it is not as simple as identifying one particular microbe on our skin that prevents a particular disease. It seems to be about proportions of populations and balance, more like an orchestra of effects. But there are absolutely correlations between eczema flares, acne, psoriasis and instances where people experience shifts in the biofilms on their skin. We’re just beginning to understand how to identify those patterns and what to do with them. Clearly the microbes on and in our skin are very important to us. Yet ways of optimizing that ecosystem are far from fully understood.