Brazilian straightening dangerous for your health? Glyoxylic acid, a substance used in this hair treatment process, is toxic to our kidneys, according to the conclusions of a study led by French researchers and published on March 20 in the New England Journal of Medicine, a renowned American scientific journal.
If it is absorbed into the body, this substance “produces oxalic acid, which can be responsible for acute insufficiency,” points out Doctor Thomas Robert, specialist in nephrology at La Conception hospital in Marseille and co-author of the study, interviewed by La Provence. This application could therefore, according to the study, cause health problems which will worsen over time with different smoothing applications.
Brazilian straightening, an application of a keratin-based product to the hair before several sessions between the heating plates of a straightener, aims to make hair shinier, silkier and easier to style. A way to restore their shine, in short.
Highlighting the dangers for the kidneys
To carry out their investigation, health professionals from Marseille and Paris hospitals, as well as the Sorbonne University, based themselves on the case of a young Tunisian woman who suffered three kidney failures over several years. Each time, these crises occurred following Brazilian straightening.
The woman was able to photograph the bottle of the product to send it to her doctor, who was able to analyze the product. The list of ingredients contained in the substance did contain glyoxylic acid, a substance which theoretically should not come into contact with the scalp to avoid irritation. But the dangers for the kidneys had never been highlighted.
In their study, the researchers present “evidence that a smoothing cream containing glyoxylic acid is responsible for nephrotoxicity (toxicity for the kidneys,
Editor’s note
)”. Kidney damage would therefore “follow transcutaneous absorption at the level of the scalp”, explains Dr Thomas Robert to La Provence, adding that over the course of straightening, “the repetition of acute kidney attacks is a risk factor. risk of developing chronic renal failure in the long term.
During their work, the researchers also tested glyoxylic acid on the skin of a mouse, and highlighted results demonstrating its toxicity.
DR Thomas Robert indicates to our colleagues that he has transmitted the results of the study to the National Agency for Food, Environmental and Occupational Health Safety (ANSES), recommending a ban on acid.