Recent research conducted by the University of São Paulo (USP) in partnership with the University of Copenhagen, in Denmark, revealed that the combination of progressive brush and discoloration it can increase the porosity of hair strands by up to four times.
Although the progressive brush can give a shiny, silky and aligned appearance to the hair, it is a “false impression that the hair is healthy and treated”, according to Cibele Castro Lima, author of the study, in an interview with Jornal from USP.
see more
Archaeologists discover 8 MYSTERIOUS chambers in an important…
Scientists are studying lunar ice, which could be important in…
The research, published in the Journal of Applied Crystallography, also delved into the individual impacts of each procedure, seeking to understand the associated risks and promote best practices for care capillary.
The recent study focused on the interaction of cosmetic treatments, such as straightening and bleaching, with the molecules of hair strands. hair.
Such treatments alter hair components, resulting in changes in physical-chemical properties and fiber mechanics, which cause curly hair to acquire a smooth appearance and dark strands to lose their pigment.
During the research, researchers focused on an active ingredient composed of glyoxylic acid associated with carbocysteine.
Although this compound is not included in Anvisa's “List of permitted active ingredients for cosmetic products for straightening or curling hair”, its use is still common in the Brazilian market.
For the experiment, strands of natural hair were subjected to three different treatments: bleaching, straightening and a combination of both.
Subsequently, varied techniques, including X-ray scattering, thermal analysis, mass spectroscopy and thermogravimetry, were used to analyze these strands.
This procedure allowed scientists to understand the effects of these treatments on hair fibers at different levels.
USP researchers identified that straightening treatments, such as progressive brushing, cause changes in the lipid layers of the hair, responsible for keeping the strands protected from harmful agents external.
This membrane is essential for preserving natural hair moisture, ensuring its softness, shine and flexibility.
The study also showed that the strands subjected to bleaching and straightening were those that showed the greatest damage to the cortex and cuticle structures.
The cortex, the middle layer of the hair, is crucial for determining characteristics such as shape, color, strength and elasticity, as it concentrates elements such as keratin, water and melanin.
(Image: disclosure)
In turn, the cuticle, the outermost layer, protects the hair with its layers of proteins. The action of these treatments compromises the hair's ability to retain water and nutrients.
The researchers also pointed out that such procedures result in the structural loss of the alpha-keratin protein, vital for hair resistance and elasticity.
Cibele Castro Lima, responsible for the study, warned of the severity of the damage: “The higher the temperature used in the process, the greater the damage to the cortex and cuticle, and these structural changes are irreversible.”
