Clean

1. The skin microbiome: A complex ecosystem essential for health

There are around a billion bacteria per square centimeter of skin. In total there are trillions, across at least a few hundred different species.

Our skin is an ecosystem. The human skin hosts a diverse community of microorganisms, including bacteria, fungi, and mites. This microbiome plays crucial roles in:

• Protecting against pathogens
• Regulating immune responses
• Maintaining skin barrier function
• Influencing skin health and appearance

The composition of our skin microbiome varies across different body sites and is influenced by factors such as age, genetics, environment, and personal care habits. Understanding and maintaining a healthy skin microbiome is increasingly recognized as essential for overall skin health and may have implications for treating various skin conditions.

2. Overzealous hygiene practices may harm our natural defenses

As clearly averse as I am to the idea of people being sold useless products based on false promises, I'm not without hope that things could get better.

Less can be more. Modern hygiene practices, while important for preventing disease, may sometimes go too far:

• Excessive washing strips away beneficial oils and microbes
• Antimicrobial products can disrupt the skin's natural balance
• Constant sanitization may weaken our immune systems

The author's personal experiment with minimal showering led to:

• Improved skin condition
• Fewer instances of body odor
• Greater attunement to the body's natural processes

While good hygiene remains crucial, finding a balance that maintains cleanliness without destroying beneficial microbes is key to long-term skin and overall health.

3. The history of cleanliness: From spiritual ritual to marketing-driven obsession

For most of human history, cleaning oneself was more about spirituality and ritual than about any modern notion of health or beauty.

Cleanliness evolved culturally. The concept of cleanliness has transformed dramatically over time:

• Ancient civilizations: Bathing as spiritual purification
• Middle Ages: Distrust of bathing due to disease fears
• 19th century: Germ theory and the rise of hygiene
• 20th century: Marketing-driven expansion of personal care products

Key developments:

• Soap industry boom in the 1800s
• Introduction of antibacterial products
• Expansion of skincare and cosmetics markets

This evolution reflects changing societal values, scientific understanding, and economic forces, often prioritizing profit over genuine health benefits.

4. The rise of the skincare industry and the quest for "perfect" skin

Insistence on using certain oils from certain parts of the world for one's soap is a luxury now made affordable for billions of people.

Marketing creates desires. The modern skincare industry has exploded, driven by:

• Social media influence and "skinfluencers"
• Promise of achieving "perfect" skin
• Constant introduction of new ingredients and products

Key trends:

• K-beauty and multi-step routines
• "Clean" and "natural" product marketing
• Luxury and premium skincare lines

While some products offer genuine benefits, many capitalize on insecurities and promote unrealistic standards. Consumers must navigate a complex landscape of claims, ingredients, and marketing hype to find truly effective solutions.

5. The hygiene hypothesis: How modern cleanliness affects our immune systems

The biodiversity hypothesis doesn't propose that hygiene is bad but that the loss of different kinds of microbes is bad—that modern inflammatory and autoimmune diseases are linked to us being deprived of exposure to the microbes we evolved to be exposed to, including pathogens as well as beneficial and neutral microbes.

Exposure shapes immunity. The hygiene hypothesis suggests that reduced exposure to microbes in early life may contribute to the rise of allergies and autoimmune diseases:

• Lack of diverse microbial exposures may lead to overreactive immune systems
• Modern environments often limit beneficial microbial interactions

Key observations:

• Lower rates of allergies in farming communities
• Increased autoimmune diseases in developed countries
• Potential links between early-life exposures and long-term health

This hypothesis emphasizes the importance of balanced microbial exposure, especially in childhood, for developing a robust and properly regulated immune system.

6. Rethinking cleanliness: Balancing hygiene with beneficial microbial exposure

Clean may defy definition, but it is rife with meaning. It can imply isolation and sterilization, or plurality and diversity.

Redefine "clean". A more nuanced approach to cleanliness involves:

• Targeted hygiene: focusing on genuinely risky exposures
• Embracing beneficial microbial exposures
• Questioning the necessity of constant product use

Practical steps:

• Reduce use of antimicrobial products when not medically necessary
• Spend time in nature and with animals
• Consider "less is more" approaches to skincare

This balanced approach aims to maintain necessary hygiene while fostering a diverse and healthy microbiome, potentially improving both skin health and overall wellbeing.

7. The global hygiene divide: Addressing inequalities in sanitation and health

While diseases like trachoma are now localized issues, Prabasi sees much more universal challenges in what's often the most difficult subject to address: menstrual hygiene.

Health requires basics. Vast disparities in access to basic hygiene and sanitation persist globally:

• Billions lack access to clean water and proper sanitation
• Preventable diseases still cause significant mortality in developing regions
• Menstrual hygiene challenges impact education and opportunity

Key focus areas:

• Providing clean water and sanitation infrastructure
• Education on basic hygiene practices
• Addressing cultural barriers to hygiene adoption

Addressing these fundamental inequalities is crucial for global health and development, often yielding significant returns on investment in terms of lives saved and improved quality of life.

8. The future of skincare: Embracing probiotics and microbial diversity

Though these products may or may not prove to help people with eczema, marketing claims will imply that they do. Combined with an enormous and solution-hungry consumer base, the stage is set for a major mainstream skin probiotic market, in addition to people who use very similar strains as prescription drugs.

Microbes as medicine. The skincare industry is increasingly exploring probiotic and microbiome-focused approaches:

• Developing products that support beneficial skin bacteria
• Researching microbial treatments for skin conditions
• Shifting from "anti-bacterial" to "pro-bacterial" messaging

Potential applications:

• Probiotic treatments for acne, eczema, and other skin disorders
• Personalized skincare based on individual microbiome profiles
• Products designed to support overall skin ecosystem health

While promising, this field is still emerging, and consumers should approach claims critically while research continues to evolve.

9. Public health and urban design: Creating environments that promote wellbeing

Olmsted's living work remains the backbone of New York City—he was among the designers of Union Square, Morningside, and Riverside parks. His vision is also carved into other cities across the country.

Design shapes health. Urban planning and public spaces play a crucial role in public health:

• Access to nature and green spaces improves mental and physical health
• Well-designed cities promote physical activity and social interaction
• Public infrastructure (e.g., clean water, sanitation) is fundamental to health

Key elements:

• Parks and green spaces in urban areas
• Walkable neighborhoods and active transportation options
• Public gathering spaces that foster community

Recognizing the interconnection between environment and health can guide urban development towards creating healthier, more livable cities for all residents.

10. Pandemic lessons: Balancing necessary precautions with long-term health considerations

The pandemic has revealed very little that is new. It has only brought preexisting contrasts into sharper relief. It has provided a concrete framework for what must be done to stay safe. But unlike the narrow, rigid directives of mid-pandemic life, the list of what must be done is at once clear and expansive.

Crisis informs progress. The COVID-19 pandemic highlighted:

• The critical importance of basic hygiene practices
• Existing health disparities and vulnerabilities
• The need for balanced approaches to public health

Key lessons:

• Importance of hand hygiene and targeted cleaning
• Value of outdoor spaces and ventilation
• Need for robust public health infrastructure and communication

Moving forward, the challenge is to maintain necessary precautions against infectious diseases while not neglecting the broader determinants of health, including beneficial microbial exposures and social connections.

Last updated: January 23, 2025