Hair straightening products may cause kidney damage according to a recent study

In a recent study published in The New England Journal of Medicine, doctors uncovered a concerning case involving a woman who experienced kidney damage following hair-straightening treatments at a salon. We talked to Dr Deepak Jakhar & Dr Ishmeet Kaur, renowned couple dermatologists at Dermosphere clinic, New Delhi to understand this case and raise awareness.

Using hair-straightening products containing a compound called glyoxylic acid could pose risks to kidney health, according to a study conducted by French researchers. They found that these products may lead to acute kidney failure due to the accumulation of calcium oxalate crystals in the kidneys. This discovery came after testing the suspected hair-straightening product on animals, where mice developed severe kidney failure within 24 hours of application. Researchers explained that the mice exposed to the straightening cream showed the presence of calcium oxalate crystals in their urine and kidneys. As a result, the researchers recommended avoiding products containing glyoxylic acid and suggested withdrawing them from the market.

The study conducted on mice showed that glyoxylic acid, upon entering the bloodstream, is converted to glyoxylate, which then metabolizes into oxalate. Excess oxalate combines with calcium in the urine, forming calcium oxalate crystals that contribute to renal failure. Such crystal accumulation is rare outside of conditions like primary hyperoxaluria or enteric hyperoxaluria, which affect liver metabolism or intestinal permeability to oxalate, respectively.

Glyoxylic acid has recently been introduced into certain cosmetic products, such as shampoo and styling lotion, for its smoothing properties. However, it's advised to steer clear of products containing this compound, especially those applied directly to the scalp. Renal complications might be underdiagnosed, the researchers noted, as symptoms can be subtle. Signs like scalp irritation accompanied by nausea or vomiting after a salon visit should raise concern.

Similar cases have been reported before, with 26 patients treated for acute renal injuries after hair straightening. Biopsies revealed calcium oxalate crystals in their kidneys. While renal function typically improves after each episode, repeated instances of acute renal failure can increase the risk of developing chronic kidney disease in the long term.

Authors of the book – ‘Good Skin Bad Skin’, Dr Deepak Jakhar and Dr Ishmeet Kaur recommends following measures:

• Avoid Excessive Exposure: Limit the frequency of hair straightening treatments, especially those containing formaldehyde or other potentially harmful chemicals. Opt for safer alternatives or embrace natural hair styling methods to reduce chemical exposure.

• Prioritize Personal Protective Measures: Salon workers should wear appropriate protective equipment, such as gloves and masks, when handling hair straightening products to minimize direct contact with chemicals and inhalation of fumes.

• Stay Informed: Stay informed about the ingredients present in hair straightening products and their potential health effects. Consult with dermatologists or healthcare professionals if you have concerns about the safety of specific treatments.

• Monitor Kidney Function: Individuals who undergo frequent hair straightening treatments or work in salon environments should consider regular monitoring of kidney function through routine medical check-ups and urine tests. Early detection of kidney damage can facilitate timely intervention and prevent further complications.

In conclusion, the findings suggest a need for caution when using hair-straightening products containing glyoxylic acid. Consumers are advised to be aware of product ingredients and to prioritize kidney health by avoiding potentially harmful compounds.

For more info:

1.  https://www.nejm.org/doi/10.1056/NEJMc2400528

2.     https://www.ajkd.org/article/S0272-6386(23)00006-9/fulltext