How Synthetic Fibers Affect Cellular Function: Understanding the Science Behind Healthier Textiles

We tend to think of clothing as passive; just something that sits on the surface of our bodies. However, research suggests clothing can actively influence our biological environment, especially at the level of the skin and its cells. This is particularly true for synthetic fibers like nylon and polyester, which interact with the body very differently from natural materials.

The Electrostatic Difference: Why Polyester Behaves Uniquely

All chemistry is about the electron structure of atoms and molecules and how those electron(ic) fields interact with each other. Polyester and nylon are not just different from natural fibers because they are synthetic. The difference is inherent in their chemistry.

For example, compared to natural fibers, polyester:

• Absorbs very little moisture
• Generates friction-based charge easily
• Resists charge dissipation

This makes polyester prone to developing localized electrostatic fields against the skin during everyday wear. These fields may be subtle, but our skin is an electrically sensitive tissue. Cells rely on voltage gradients and ion flow to regulate:

• Growth
• Signaling
• Repair
• Hair follicle cycling
• Inflammatory responses

So, it stands to reason that small b sustained electrical disturbances can influence biological behavior. Early research demonstrates this.

Evidence from Textile Research

In addition to notoriety as an expert surgeon in pelvic, urological, and gynecological physiology and an accomplished researcher publishing over 500 peer-reviewed articles and developed several new and effective surgical techniques for patient treatment, in the early 1990’s and until his death in 2007, Professor Ahmad Shafik of the Faculty of Medicine at Cairo University also conducted a series of controlled textile experiments that provided convincing evidence and insights supporting a hypothesis of electrostatic field effects impacting cellular health and function. Though work was not done to parse out the exact mechanistic processes of how cell function is affected, the observations were made with rigorous control for other parameters.

For each of those studies, a concise and clear summary is provided here:

Effect on Skin Health and Hair Growth

There was a study involving 40 dogs wearing textile patches. The dogs were split into groups wearing :

• 100 % polyester
• 50% / 50% Polyester / Cotton
• 100% cotton  
• 100% wool
• a control with no fabric

After two months, the polyester-covered areas had:

• Significantly reduced hair growth rate
• Lower hair density
• Thinning in the outer layer of skin (epidermis)
• Damage within the hair follicle pulp\

Cotton and wool patches showed no significant differences relative to uncovered skin.

The proposed mechanism is that friction between polyester and skin generated an electrostatic charge, creating a localized field that appeared to interfere with normal follicle function.

Effect on Reproductive Systems in Mammals

1.      Effect on Fertility in Male Dogs

In a study with 31 dogs split into groups wearing polyester underpants, cotton underpants, or no underpants, the following observations were made.

All of the dogs wearing polyester had:

• Decreased sperm count
• Decrease in numbers of motile sperm
• Remaining sperm showed an increase in abnormal formation

·        Degenerative testicular changes were observed as cytoplasmic vacuolization in the Sertoli cells. These are cells that support and nourish developing sperm cells inside the seminiferous tubules within the testes, in part, by surrounding them to create the blood-testes barrier to protect developing sperm cells from the rest of the immune system.

The changes were statistically shown to not be due to any changes in temperature or hormones (LH , FSH, and prolactin) whereas there was a measurable electrostatic potential built-up n the skin. The changes were mostly reversible – further supporting the electrostatic potential theory. Sperm count and health started to recover 3-6 months after the polyester stopped being worn. Pre-experimental levels of sperm count and health were achieved by 4 dogs after 7 months, by another 6 dogs after 11 months.  Two out of 12 dogs that wore polyester had not recovered after 12 months of observation and biopsy showed persistence of the tubular degeneration that occurred while they wore the polyester pants.

No electrostatic charge or any of the other negative impacts were observed in the dogs wearing cotton or nothing at all.

2.      Effect on Conception in Female Dogs

In another study, 35 female dogs were split into five groups and wore either 100% polyester, 100% cotton, 100% wool, a 50:50 polyester-cotton mix underwear, or no underwear for 12 months. The underpants were loose fitting with openings for biological functions. Five of the 7 dogs wearing 100% polyester experienced significantly decreased progesterone and could not become pregnant on mating or insemination. Three of the 7 wearing a 50:50 poly-cotton blend experienced the same inability to conceive. It is hypothesized that this is because the polyester causes an electrostatic potential on the skin and this inhibits the proper function of the ovaries and subsequent hormone production and egg follicle maturation and release.

None of these effects were experience by the dogs wearing natural fiber textiles.

Notably, a consistent electrostatic charge developed and was measured on the dogs wearing 100% polyester and a charge of half that magnitude was measured on the dogs wearing the 50:50 blend – further indicating a link between synthetic content of the fabric and the charge development.

Other Studies (with humans)

There are additional studies that demonstrate a reduction in sperm count, increase in deformed sperm, and loss of functional sperm in human males. Though done with rats, another study showed a decrease in sexual activity in male rats and a decreased intromission (entering the female) due to an effect on the physical penile structures, again, seemingly via electrostatic effects.

These studies highlight that synthetic materials can interact with biological systems in unexpected ways, especially through electrostatic fields. The question one might ask is, “Is this even plausible?”

The answer is that all textiles and all human tissues have a dielectric properties and many biological or biochemical processes are driven or mediated by chemical/electric/ionic charges.

Understanding of Bioelectrical Processes Sheds Light on these Observations

In the decades since Professor Shafik’s work, advancements in understanding of mechanistic cellular science have shown that:

• Cells maintain a resting membrane potential, a small internal voltage difference essential for function.
• Electric fields can influence cell orientation, movement, and growth.
• Ion channels - tiny protein pores - respond to electrical cues.
• Tissue regeneration and inflammation are electrically regulated processes.

This modern understanding supports the idea that externally generated electrostatic fields (like those from synthetic polymer fibers) may influence local cell behavior, while natural fibers remain electrically neutral.

Why Are Natural Fibers More Skin and Human- Compatible?

Natural fibers (cotton, hemp, wool, linen, silk) have fundamentally different properties:

• They absorb moisture, reducing static buildup (naturally anti-static)
• They offer superior breathability (humidity and thermal regulation)
• They don’t inherently carry with potentially hormone disrupting small molecules
• They don’t produce environmentally persistent microplastics that harm the planet and the people who end up consuming them through food and water sources

This aligns with research consistently showing neutral or beneficial outcomes when natural fibers are in contact with the body.

Implications for Skin, Comfort, and Long-term Wear

Even if the effects are subtle for short term exposure, synthetic static charge may influence:

• Hair follicle activity
• Skin barrier performance
• Irritation levels
• Inflammatory sensitivity
• Overall cellular microenvironment

This helps explain why some people experience itching, dryness, or discomfort with synthetics, even when temperature, fit, or detergents are not the cause.

Rethinking Apparel Through a Biological Lens

We’re entering a new era where consumers increasingly want clothing that feels good, performs well, and supports well-being as awareness increases of the intersection between material science, human physiology, and sustainability.

For Namarie, this means:

• Designing with natural, non-charge retaining fibers
• Using proven, safe and non-toxic dyes and finishes
• Prioritizing long-term biological compatibility

In short, clothing that works in harmony with the body.

Explore Clothing Designed for Human Biology

Namarie creates apparel that respects the body’s natural systems and the planet’s.
To learn more—and explore biologically aligned, sustainable textiles—visit our website.

This article was written by Dr. Mansour AbdulBaki.

Mansour is the Chief Science Officer and a Founding Partner at Namarie. He earned his PhD from the Chemical and Biomolecular Engineering Department at the University of Houston. At Namarie, he now applies his expertise to rethink performance textiles, innovate in manufacturing processes, and lead the development of our Sylvendel fabric.