Skin lightening creams laden with mercury take a toll on the kidney
Researchers from Kerala have reported a series of cases from Malappuram district where the regular use of fairness creams has been linked to nephrotic syndrome. Heavy metal screening of the blood and urine samples of these patients revealed high levels of mercury, the toxic e ects of which are well-known
On the heels of recent news reports on how keratin-based hair-straightening products containing glycolic acid derivatives led to severe kidney injury in women, researchers from Kerala have reported a series of cases wherein the use of fairness creams has been linked to nephrotic syndrome.
In a study published in the latest issue of Kidney International (‘NELL-1 associated membranous nephropathy linked to skin fairness cream use — insights from an Indian case series’), doctors describe a series of 15 cases of Membranous Nephropathy, reported by Aster MIMS Hospital, Kottakkal, Malappuram district, that were traced to the regular use of fairness creams. Heavy metal screening of the blood and urine samples of these patients revealed high levels of mercury, the toxic eects of which are well-known. An analysis of the fairness creams also showed that these contained high levels of mercury — in some instances, 10,000 times above the permissible limit of 1 ppm.
High proteinuria
Since 2021, Ranjith Narayanan, a nephrologist practising at two busy private hospitals in Kozhikode, had noticed a specic pattern in cases of membranous nephropathy diagnosed amongst his patients. They all had non-specic symptoms — fatigue, mild edema and frothy urine — but high levels of proteinuria, in the range of 6.5-22.2 g/day.
Membranous nephropathy (MN) is an autoimmune disease resulting in nephrotic syndrome, a condition when too much protein is released into the urine (proteinuria), ultimately resulting in renal failure. In approximately 70% to 80% of cases of MN, the target antigen has been phospholipase A-2 (PLA2R). However, in early 2023, when four or ve cases of MN with a similar prole turned up consecutively in OP clinics, Dr. Narayanan and his colleagues decided to dig deeper. In this instance, most of the MN cases turned out to be PLA2R negative.
Recently, another antigen, Neural epidermal growth factor-like protein 1 (NELL-1), has been linked to a rare form of MN. A lab in Chennai identied all these patients to be positive for NELL-1. “In Tamil Nadu, most cases of MN caused by NELL-1 have been traced to use of traditional medicines, most of which have high levels of mercury. But all our patients denied using any indigenous medicines. The link between face creams containing mercury and nephrotic syndrome is well-established worldwide, which naturally led us to probe the use of cosmetics,” says Dr. Narayanan.
Fairness cream
The patients admitted to fairly regular usage of fairness creams before they began experiencing non-specic or subtle symptoms. The research team then began prospectively evaluating all cases of MN and they also revisited cases from the past two years. Their study reports 15 cases of MN linked to NELL-1 and in 13 cases, patients had a history of use of fairness creams, most of which were unregulated brands oering rapid results and sold rampantly in local shops and on online platforms.
The key to limiting further kidney damage was recognising the actual cause of nephrotic syndrome by diligently focussing on the patient’s clinical history. The mercury levels in blood/urine samples dropped within three months of the patients stopping the use of their fairness creams. Also, all patients responded well to RAAS (renin-angiotensin-aldosterone system) blockade (the gold standard therapy for chronic kidney disease) and did not need immunosuppression.
“Our patients were lucky that we pinpointed the incriminating agent (fairness creams) early, so that renal function could be preserved in all patients and complete remission was possible within 6-11 months,” says Dr Narayanan.
The obsession with fair skin and the use of skin lightening products extends well beyond India and is said to be widely prevalent in African and Asian countries. However, despite widespread use, the serious systemic health issues that toxic cosmetic creams can induce are yet to be perceived as a global public health issue.
Impact of mercury
Mercury is a highly toxic heavy metal which is used in fairness/anti-ageing creams as in its inorganic form (mercury salts) it can inhibit the formation of melanin resulting in a lighter skin tone. The higher the levels of mercury in face creams, the better the whitening eect. This is naturally perceived as the product’s eectiveness by gullible consumers, who become loyal customers of the product.
Chronic mercury poisoning from cosmetics is often missed because dierent organs and tissues respond dierently to mercury, resulting in atypical clinical presentations. Physicians need to be made more aware of the possibility of mercury poisoning when patients present with non-specic symptoms like pain, fatigue, cognitive decline or systemic issues like membranous nephropathy. However, the concept of equating beauty with fair skin is so ingrained in the minds of people that even after abundant cautioning, they are reluctant to stop the use of fairness creams, doctors say.
The larger public is unaware that mercury in face creams can be absorbed through the sweat glands, sebaceous glands, and hair follicles and absorbed by all tissues. Repeated topical use results in systemic toxicity, manifesting as damage to the kidneys and nervous system. The other adverse eects listed by WHO include skin discolouration and scarring, reduction in the skin’s resistance to bacterial and fungal infections, anxiety, depression, psychosis and peripheral neuropathy. “We nd that there is little acceptance from people to stop the use of a particular face cream because as soon as they stop using it, the skin becomes dark again.
Changing the attitude of society about skin colour is thus the larger challenge,” Dr. Narayanan says. The Minamata Convention on Mercury, to which India is a signatory, is a global treaty “to protect human health and the environment from anthropogenic emissions and releases of mercury and mercury compounds” and it has been in force since 2017.
According to a new Zero Mercury Working Group (ZMWG) report released in October 2023, despite being banned by a global treaty, mercury-containing skin lightening products are still sold by some of the world’s biggest online retailers to unsuspecting consumers. It said that of the 213 fairness products from 12 countries purchased and tested by NGOs, 191 (90%) had mercury concentrations ranging from 1.18 to 74,800.00 ppm of mercury, way above the 1 ppm limit mandated for cosmetics by many governments as well as the Minamata Convention.
“The strength of the current study was that it could establish the temporal relationship between the use of fairness creams and the occurrence of nephrotic syndrome. However, larger, multi-centric systemic studies on chronic mercury poisoning are required not just to understand the extent of the problem but also to persuade policy makers and regulators to clamp down on all cosmetics containing mercury at all,” the researchers say.
An analysis of the fairness creams showed that these contained high levels of mercury — in some instances, 10,000 times above the permissible limits of 1 ppm