Could products used to straighten hair be harmful to the kidneys? This is the question that French researchers asked themselves. In new study published in The New England Journal of Medicine (NEJM), French nephrologists from the Conception Hospital in Marseille, have made a link between glyoxylic acid contained in products used to straighten hair and kidney risks.
Can hair straightening products affect the kidneys?
In their publication, the researchers describe the case of a young 26-year-old Tunisian woman with no health problems but who suffered three consecutive episodes of acute kidney injury after a straightening product containing 10% glyoxylic acid caused her to been applied to the hair. The latter had “vomitings, diarrhea, fever and back pain. Laboratory tests showed an increase in plasma creatinine level during each episode”we can read in particular in their work.
If the patient’s renal function improved rapidly each time, “the repetition of episodes of acute renal failure is however a major risk factor for developing chronic renal failure in the long term”, specifies Professor Emmanuel Letavernier, one of the researchers who participated in this work, interviewed by Medscape.
To find out more, the researchers carried out an experiment on mice. They applied the same smoothing product containing 10% glyoxylic acid to the upper backs of five rodents. Five other mice were exposed to a so-called “control” product. Blood samples were taken “to assess renal function (plasma creatinine)”it is specified in the work, and urine analyzes were also carried out.
Kidney health: smoothing products containingglyoxylic acid should be removed from the market, researchers say
What was the impact of the glyoxylic acid contained in these products on these rodents? According to Professor Emmanuel Letavernier, the results on mice are “spectacular”. He thus specifies that“they develop kidney failure extremely severe acute within 24 hours after application of the smoothing cream. The samples show the presence of calcium oxalate crystals in all the renal tubules”.
In light of these results, the researchers therefore believe that “Given the potential nephrotoxicity of topical glyoxylic acid, products containing this compound should be avoided and, in our opinion, removed from the market”we can read at the conclusion of this work.
As a reminder, a study published in 2022 in the Journal of the National Cancer Institute reported “the first epidemiological evidence of an association between the use of hair straightening products and uterine cancer”. In question ? An ingredient used in the composition of these products: formaldehyde. It was then replaced by glyoxylic acid, which in turn presents risks for the kidneys, as revealed by this new French study.
Sources:
- Kidney Injury and Hair-Straightening Products Containing Glyoxylic Acid – The New England Journal of Medicine (NEJM), 03/21/24
- Warning on the risk of acute kidney failure with certain hair straightening products – Medscape, 03/20/24
- Use of Straighteners and Other Hair Products and Incident Uterine Cancer – Journal of the National Cancer Institute (10/17/22)