For some people, getting their hair styled is a routine task: make an appointment, show up, clean up, and leave. For Janet Wangari Olivero, it’s an expedition.
At first, it was difficult to find a stylist with training and experience cutting and styling curly hair like hers. It was an hour’s journey from her home in rural, overwhelmingly white Hunterdon County, New Jersey, to Maplewood, a diverse inner-ring suburb of Newark, where she finally found a good place. i got you. Then there’s the pre-appointment prep, like pre-washing and detangling, which many stylists ask their curliest-haired clients to do before arriving.
“It’s a half-day experience,” says Wangari Olivero. “Don’t rush to take care of your curly hair.”
Hair care is different for the curliest of people, including black women like Wangari Olivero, a former cancer researcher and current assistant vice president of research and innovation at L’Oréal.
Curly hair itself is also different. The structure, function, and development of human hair have been extensively studied. By 2030, 40% of the world’s population is expected to have curly hair. However, most research has focused on straight or wavy hair, and understanding the nature of curly hair has long been on the back burner. As a result, research on curly hair has lagged significantly.
Classification of curls
Hair, protein-rich filaments that grow from hair follicles in the skin, are a hallmark of mammals, and human hair ranges from pin-straight to tightly coiled. But for most of the 20th century, there was no scientific way to classify hair by its frizz. Instead, they were classified as European, Asian, or African by geographic or ethnic origin. However, Polynesians and Europeans have curly hair, Africans have straight hair, and there are variations in hair twists and textures. “Hair is so diverse,” says Wangari Olivero.
In the 1990s, celebrity hairstylist Andre Walker developed a typing system that became popular among stylists. However, this system, which categorizes hair into straight, wavy, curly and kinky forms, has been criticized as an oversimplified and unscientific marketing tool.
To apply science to curly hair, in 2007 researchers at L’Oréal developed an objective method to classify curly hair regardless of race.
They collected hair from about 2,500 people in 22 countries and from three different parts of each person’s head: the top of the neck, the temple, and the nape of the neck. Each hair sample was washed and dried, placed on a glass plate to preserve its natural shape, and the tightness of the hair’s curls and number of waves and twists were measured. From these measurements, they classified human hair into eight types, ranging from pin-straight to tightly curled.
As the natural hair movement gains momentum with the rise of social media, more and more people with curly, kinky, and wavy hair are embracing their hair for what it is, replacing the hair that was often previously damaged. I no longer use hair relaxers or hair straighteners. Generations used it. The beauty industry began to change, developing more products for customers with naturally curly hair.
L’Oréal researchers have characterized the biophysical properties of all types of human hair.
Image provided by: L’Oreal Group
complex fibers
Despite its diversity, all human hair has a similar composition. It grows from specialized epidermal cells beneath the skin’s surface and forms three layers: the medulla, the cortex, and the cuticle. The innermost or core layer, the medulla oblongata, is mostly confined to thick, coarse hairs. The outermost layer, or cuticle, provides protection and is an important indicator of hair health.
The middle layer, or cortex, creates curls. Fur consists of spring-like protein molecules called keratin, which gives hair strength, and melanin granules, which determine hair color, and contains two types of cells. In straight hair, they are arranged in concentric circles, while in curly hair, they are arranged asymmetrically, making it easier to create twists.
Stylists have long noticed that curly hair is more prone to breakage than straight hair. Using a device that pulls hair until it breaks, L’Oréal researchers found that its spring-like structure actually causes curly hair to break at low growth rates. Further research revealed that the cause was torsion. Twisted hair is a vulnerable area that breaks more easily than untwisted hair.
Since tangles are the enemy of curly hair, effective detangling products are in high demand. To create these, L’Oréal scientists first visited the European Synchrotron Radiation Facility in Grenoble, France, and exposed tangled curly hair to X-rays. By virtually slicing and reconstructing the resulting images using data analysis and AI, we created the first 3D rendering of such entanglements, showing how the hairs within intersect and interact. , revealed how it changes shape.
“Structural insights like this could lead to better detangling,” said Dakota Piorkowski, senior scientist on L’Oréal’s research and innovation team, who presented the results at the World Hair Research Congress in Dallas in April. There is a possibility that this could lead to damage to the product, and damage can also be prevented.” “The idea we’re driving is that each curl pattern requires a customized solution,” he says.
Clues to discovery
Researchers need to find and test new formulations to develop products customized for curly hair. To better predict which will work, L’Oréal is collaborating with Karl Koehler, a regenerative medicine expert and assistant professor at Harvard Medical School.
In a 2020 Nature paper, Köhler and colleagues solved a 50-year-old problem by inducing two types of stem cells to grow into organoids (floating spheres of skin tissue grown in the lab) that grow human hair. did.
Koehler is now able to grow skin that matches the donor’s pigmentation and sprout hair that replicates the donor’s hair texture. Ultimately, hair-producing skin organoids grown in the lab could serve as a guinea pig for drugs to treat burn scars and androgenetic alopecia in people with all types of hair, Koehler says. he says.
Back in L’Oréal’s lab, skin organoids can also be used to test ingredients in new hair products and develop custom formulations. And as our scientific understanding of hair advances, so too does our understanding of the people who adorn it. “Hair growing out of your head is normal, beautiful, unruly and nothing to be ashamed of,” says Wangari Olivero. “It’s a symbol of beauty and we want people to embrace it that way.”
Explore more new insights into curly hair and developing personalized hair care in this video and this podcast. To learn more about L’Oréal’s science-based innovations, check out this dedicated resource.
