cuidado del cabello
Sumérgete en el mundo del cuidado del cabello con "Haircare Decoded". Sabemos que navegar por la amplia gama de productos y tratamientos capilares puede resultar abrumador. Por eso nos hemos comprometido a ofrecerte soluciones eficaces y accesibles para cada necesidad capilar. Con fórmulas limpias y altamente eficaces, la gama JUST aborda los problemas capilares más comunes. Desde ingredientes fortalecedores hasta tratamientos revitalizantes, tenemos todo lo que necesitas. Pero, ¿cómo determinar tu tipo de cabello? ¿Qué productos se adaptan mejor a tus necesidades capilares y te ofrecen los resultados que deseas? Todo empieza con la Biología Capilar, y te invitamos a embarcarte en este viaje para descifrar todos sus secretos.
Estructura capilar
El pelo está presente en casi todas las superficies de la piel humana. Es un fino hilo de queratina de gran resistencia y elasticidad. Cada pelo consta de una raíz incrustada en la dermis y un tallo piloso que sobresale de la superficie de la piel. La raíz está rodeada por un revestimiento tubular formado por células epiteliales llamado folículo piloso. La base de la raíz y el folículo piloso son ligeramente más grandes que el resto de la raíz; esta estructura en forma de cebolla se denomina bulbo piloso.
El bulbo piloso recibe oxígeno y nutrientes a través de los vasos sanguíneos que abastecen a las células que crecen activamente en el folículo piloso alrededor del bulbo piloso, conocidas como matriz pilosa.
Estas células son la única fuente de cabello nuevo. El tallo piloso propiamente dicho surge de la región del bulbo de la raíz y es producido por queratinocitos de la matriz que se multiplican rápidamente. El tallo está formado en su totalidad por células muertas compuestas principalmente de queratina. Estas células permanecen unidas entre sí por una sustancia intercelular similar al cemento.
Anatomía del cabello
Si se hace un corte transversal de un tallo piloso se encontrarán tres componentes principales, desde el exterior hacia el interior: la cutícula, el córtex y la médula.
Cutícula
Cortex
Médula
La estructura más externa es la cutícula. Se compone de múltiples capas de células queratinizadas y aplanadas, que se superponen en forma de teja. Es translúcida, lo que permite que la luz penetre en los pigmentos de la corteza. Está compuesta principalmente de queratina. La cutícula regula el contenido de agua de la fibra capilar y es responsable del brillo y la textura del cabello. La cutícula es el objetivo de los productos acondicionadores del cabello. Un cabello brillante y suave refleja una cutícula sana, mientras que un cabello seco y quebradizo es el resultado de células de la cutícula dañadas.
La corteza se encuentra debajo de la cutícula y contribuye a las propiedades mecánicas de la fibra capilar, como la resistencia, la elasticidad y el rizado. El córtex está formado por células alargadas ricas en filamentos de queratina y una matriz amorfa de proteínas azufradas
. Durante el envejecimiento, la cantidad de pigmento producido es menor y ésta es la razón del encanecimiento del cabello. Además, los cambios que se producen en la coloración oxidativa del cabello, la ondulación y el alisado permanentes y el peinado térmico tienen lugar en el córtex. El córtex, al igual que la cutícula, tiene una gran importancia cosmética, ya que sus propiedades ópticas afectan en gran medida al color y al brillo de la fibra capilar.
La médula (el "núcleo") está compuesta por células aplanadas y cornificadas. Se ve como un armazón de queratina.
Ciclo de crecimiento del cabello y caída del cabello
El crecimiento del cabello es un proceso único y complejo que implica ciclos continuos de crecimiento y regeneración (fase anágena), transición (fase catágena) y reposo (fase telógena). La actividad cíclica continúa durante toda la vida, pero las fases del ciclo cambian con la edad.
Fase anágena
Durante la fase anágena, se producen nuevos cabellos en la parte inferior del folículo piloso. Normalmente, la mayor parte del cabello del cuero cabelludo (aproximadamente el 85-90%) se encuentra en fase anágena en cualquier momento. En el cuero cabelludo, la fase anágena puede durar de 2 a 6 años, pero en algunos casos puede ser más larga. Cuanto más larga sea la fase anágena, más tiempo podrá crecer el cabello. La diferencia en la longitud del cabello de cada persona puede estar relacionada con la duración variable de la fase anágena. El vello del cuero cabelludo crece a un ritmo normal de aproximadamente 1 mm cada 3 días. El vello de los brazos, las piernas, las pestañas y las cejas tiene una fase anágena mucho más corta y un ritmo de crecimiento más lento, lo que explica que sea mucho más corto que el del cuero cabelludo.
Fase catágena
La fase catágena es una breve fase de transición entre las fases de crecimiento y de reposo, que marca el final de la fase de crecimiento. En el cuero cabelludo, la fase catágena
catágena suele durar entre 2 y 3 semanas.3 Durante esta fase, la división celular
Durante esta fase, se detiene la división celular, el tubo folicular se encoge y se desprende de la papila dérmica, y el folículo se contrae.
base del folículo se desplaza hacia arriba, hacia la superficie de la piel. La producción de melanina se detiene en esta fase, lo que da lugar a un extremo inferior no pigmentado en el pelo.
Fase telógena
La fase telógena es la fase final y dura hasta que el pelo completamente crecido se desprende.
El pelo se desprende durante la fase telógena o permanece en su sitio hasta la siguiente fase anágena, en la que crece el nuevo pelo.
lo expulsa. En el cuero cabelludo, la fase telógena suele durar aproximadamente
2-3 meses. En cuanto finaliza la fase telógena, el cabello vuelve a la primera
primera fase y todo el ciclo comienza de nuevo. Aparecen nuevos cabellos en el mismo folículo.
La eliminación de los pelos telógenos es fácil e indolora, son los folículos pilosos que
salen durante el lavado con champú o el peinado.
¿Cómo saber si se está perdiendo el cabello telógeno o anágeno?
La forma y el color del bulbo son diferentes en los pelos telógenos y anágenos. Los bulbos telógenos tienen forma de maza y, a diferencia del vello anágeno, su base carece de pigmento. Puede verse claramente con una lupa.
Otros factores que influyen en el crecimiento del cabello son los factores sistémicos, como las hormonas, incluidos los andrógenos, los estrógenos y las hormonas tiroideas; los factores de crecimiento y las citoquinas; así como los factores externos relacionados con el medio ambiente, como las toxinas y las deficiencias de nutrientes, vitaminas y energía.
Composición química del cabello
Hair fibers are primarily composed of various types of keratin. The keratin fibers consist of long molecular chains intertwined and firmly attached through various bonds. Bonds found in hair fibers are generally classified as strong bonds and weak bonds.
Strong bonds
Disulfide Bonds:
Hair keratin is made up of amino acids, where cysteine is one of the most important among them. Cysteine molecules with their sulfur atoms are able to form a very strong bond known as the disulfide bond. They contribute much to the shape, stability, and texture of the hair. When two cysteine molecules are bound together through a disulfide bond, a molecule called cystine is formed. Disulfide bonds are called strong bonds, because they cannot be broken up by heat or water, only chemically. These bonds remain intact when the hair is wet, allowing the hair to resume its original shape.
Weak bonds
Hydrogen Bonds (H-bonds):
H-bonds are relatively weak and can be easily broken by water and heat. They are primarily responsible for changing the hair’s overall shape. Although individual H-bonds are weak, they are present in the highest number of all types of bonds; therefore, they significantly contribute to the strength of hair fibers.
Salt Bonds:
Also known as ionic bonds, are sensitive to pH; therefore, they are easily broken by strong alkaline or acidic solutions. Although these are weak bonds, together they account for a significant part of the strength of hair fibers.
Van der Waals Forces:
These forces are weak attractive forces between neutral molecules in close contact. They can also be easily broken by water and heat.
Hair types
Based on Color
Natural color is the result of melanin present in the cortex. There are two types of melanin: eumelanin, which provides dark brown and black color to hair, and pheomelanin, which provides red to blond tones.
Naturalhair color ranges from black, brown, and blond to red with subtle hues in each category. The diversity of hair pigmentation results mostly from the quantity and ratio of eumelanin and pheomelanin.
Based on Condition
The hair’s condition refers to the smoothness and softness of the hair by touch, which is in direct relationship with the cuticle’s intactness. This is commonly called porosity, which reflects the hair fibers’ ability to absorb moisture.
- Healthy hair with a compact cuticle layer is naturally resistant to moisture.
- If the cuticle is damaged, hair has a course texture and loses its shine and smoothness. In such cases, the cuticle is raised, meaning that the layers are not tightly packed. This type of hair is referred to as porous or overporous hair if damaged severely. Porous hair can absorb liquids very easily and quickly and tends to develop split ends.
The hair fibers’ condition should be considered before undergoing chemical processes, such as hair coloring since the needs of damaged and healthy hair are different.
Based on Curliness
Refers to the shape of the hair shaft. There are a variety of categories describing the curliness of hair, including straight, wavy, curly, and kinky, among others. The conventional classification of curliness distinguishes three types of hair: African, Caucasian, and Asian. Usually, Asian hair is the thickest, followed by African hair, and then Caucasian hair. An additional feature is the cross-sectional shape of the hair fibers: Caucasian and Asian hairs typically has a similar round shape, with the Asian hair being more cylindrical, while the African hair has a highly elliptical shape.
Today, we can find hair types that would not fit into these three basic categories. Therefore, there are newer classifications developed that categorize hair into more than three groups, regardless of its ethnical origin.
Based on Greasiness
Based on greasiness, two major hair types are usually differentiated- dry and greasy hair.
Dry hair does not contain enough moisture. It is usually a result of damaged cuticle and cortex. Porous cortex cannot retain water; therefore, hair fibers have dull, unhealthy appearance.
Dryness is usually aggravated by excessive shampooing and chemical treatments, such as permanent waving or bleaching. Extremely dry hair needs special care and mild cleansing agents not to worsen the damage.
Greasy hair is usually caused by overactive sebaceous glands, which produce more sebum than normally. Since sebum production is highly influenced by hormones, many consumers experience greasy hair when changes take place in their hormone levels, for example, during puberty. In such cases, the hair may become greasier and need to be washed more often. Greasy hair needs special care because if not cleaned adequately, it can lead to various scalp conditions, such as dandruff.
Hair cleansing
Shampoos are one of the most widely and frequently used personal care products today.
The main benefit of using shampoos is the removal of dirt on the hair. Similarly to dirt on the skin, dirt on the hair consists of sweat, sebum and its breakdown products, dead skin cells, residues of cosmetics and personal care products, dust, and other environmental impurities carried in the air.
Most of these compounds are not soluble in water; therefore, washing the hair with simple water would not be sufficient to remove dirt. Shampoos contain surfactants (similar to skin cleansers), which are able to remove oily particles from the hair.
From the aspect of their chemical nature, shampoos are surfactant-based preparations. Therefore, their cleaning principle is emulsification. Surfactants surround and trap tiny droplets of fat, which in this form can be rinsed off from the hair and scalp. Insoluble particulate soil can be removed by electrostatic repulsion between the soil and the hair fiber assisted by repulsion between the surfactant molecules adsorbed onto the hair fiber and those dissolved in the soil.
Today shampoos are available as liquids, gels, emulsions and powders. Most commonly, shampoos are colloidal dispersions of various surfactants in water. Basic components of a classical shampoo are cleansing agents, thickeners, and water. Usually, various additives are also incorporated in the formulations in order to help the cleansing process, enhance the aesthetic properties, increase foaming, and make the hair shine.
What is the role of surfactants and are they different?
Surfactants aid in cleaning and foaming by reducing the surface tension between two phases. In addition, surfactants can also act as foam boosters and foam stabilizers. Typically, several surfactants are combined to achieve the desired result. For example, shampoos for oily hair contain surfactants with strong sebum removal qualities, unlike those for colored hair that are gentler to the hair. Different surfactants, however, have different characteristics and effects on the hair and scalp. Anionics can make the hair extremely clean, but will leave it with a rough, harsh feeling; while nonionics can increase luster and shine, but they do not foam as well as anionics.
Hair conditioning
Conditioners are applied to the hair after shampooing and are designed to smooth the hair, improve gloss and luster, as well as recondition chemically damaged hair (by permanent waving, hair bleaching, or hot blow-drying), mechanically damaged hair (by excessive brushing), and weathered hair (by sunlight, salty seawater, chlorinated water, or swimming pools).
Conditioners act by reducing static electricity generated after combing dry hair, improving manageability by filling in the gaps around and between the cuticle scales, increasing hair shine by coating hair shafts with a thin layer,decreasing split ends, and improving hair flexibility. Natural sebum is the ideal conditioner. Excessive removal of sebum leads to a harsh and dull appearance of the hair, and it necessitates the use of synthetic sebum-like products.
Conditioners make the hair soft, shiny, and easier to manage. Although the main purpose of using shampoos is to clean the hair, overcleaned hair looks dull and has less shine. Conditioners can be incorporated into shampoos; products containing such ingredients are usually referred to as two-in-one shampoo and conditioner formulations. Conditioners are particularly important in dry hair shampoos and shampoos for colored and bleached hair.
Examples for commonly used ingredients include quats (a type of cationic surfactant); humectants, such as glycerin; proteins; silicones, such as dimethicone)
Interesting Fact
Hair becomes more negatively charged after brushing. These negative charges repel each other and make the hair look frizzy.
Hair is one of the most important features when it comes to first impression and is strongly connected to attractiveness and confidence. Styled, well-kept hair gives the external appearance of being well managed, which in turn can contribute to feeling the same way internally. The key motivator for coloring the hair is graying. Graying can have a significant effect on both men and women, including emotional and psychological stress as well as lowered self-esteem.
Additionally, people are rarely satisfied with their natural hair color. A wide variety of hair coloring products offers an option to everyone to alter their hair color, which can also contribute to self-esteem and confidence.
Nowadays there are different types of hair-coloring products based on the presence or absence of the chemical reaction (known as oxidation) involved in the hair coloring process. Non-oxidative products include temporary dyes and semi-permanent dyes, while demi-permanent dyes, permanent dyes, and hair bleaches fall into the category of oxidative products.
Non-Oxidizing Products
The products that belong to this category do not contain oxidizing agents, as their name implies. As a result, non-oxidizing dyes are not able to produce lighter shades than the originally presenting shade and cannot significantly darken the originally presenting color.
Temporary Dyes
Temporary dyes or color rinses usually contain molecules that are too large to penetrate the hair cortex and also have low affinity to hair, meaning that the binding forces between the hair cuticle and the dye molecules are low. As a result, temporary dyes provide a weak coating on the hair cuticle and are easily washed out after the first shampooing. (color rinses, color-enhancing shampoos, hair color sprays, mousses, gel products)
Semi-Permanent
Dyes Semi-permanent hair dyes usually employ dyes that are small enough to penetrate the hair cuticle to some degree, in addition to staining it from the outside, and, hence, remain on the healthy hair through 6–8 shampooing.
The pH of semi-permanent dyes is slightly alkaline (7.0–9.0), making the cortex to swell and rise. It allows a certain degree of penetration of the dye into the deeper layers of the cuticle. Washing the hair opens the cuticle, allowing the color to escape over time because of the solubility of the dyes in water. (lotions, shampoos, gels, creams, and mousses).
Oxidizing Products
Oxidizing hair dyes are two-component systems: one component contains colorless dye and couplers in a highly alkaline formulation. The other component contains hydrogen peroxide (the oxidizing agent, otherwise known as the developer or activator). These products are mixed right before application, which generates a chemical reaction. The alkaline agent swells the hair cuticle and thus helps the penetration of the relatively small dye intermediates into the cortex. In addition, it also destabilizes hydrogen peroxide to liberate oxygen. The oxygen released destroys the hair’s natural melanin (i.e., lightens hair) and also oxidizes the dye intermediates and allows them to react with the couplers within the hair shaft to form a colored molecule. The final color molecule is too large to be removed by shampooing, which makes the color resistant to shampooing. (permanent, demi-permanent dyes, bleachers).
Interesting Fact!
Red shades tend to fade fastest as they have a relatively small molecule size, which can diffuse from the hair and wash away more quickly than other shades.