Skin fairness creams not fair to the kidneys

A recent review integrates multiple research findings and turns the spotlight on the growing nephrotoxic threat posed by skin-whitening creams.

“The timeless tale of Snow White, with its emphasis on fair skin as a beauty ideal, mirrors a contemporary issue in nephrology: the harmful impact of skin-whitening creams on kidney health,” said the researchers.

“We present evidence … connecting mercury (Hg)-containing creams to nephrotic syndrome,” they said. A frequent ingredient of cosmetic products, Hg disrupts melanin synthesis by inhibiting tyrosinase, leading to serious health risks, including nephrotoxicity. [Clin Kidney J 2024;doi:10.1093/ckj/sfae358]

MGN, MCD

Fairness creams are heavily implicated in the development of glomerular diseases like membranous glomerulopathy (MGN) and minimal change disease (MCD) – two of the most common GNs tied to cosmetics use.

In a retrospective analysis, histopathology results revealed that 60 percent of the 35 participants had MCD and 37 percent had MGN. [BMC Nephrol 2019;20:228]

Another retrospective study on 172 individuals with Hg poisoning showed that of the 46 participants who had kidney damage, 41 had nephrotic syndrome while five had proteinuria. [Kidney Int Rep 2022;7:1189-1197] “MGN was the predominant pathological finding (51.43 percent). Remarkably, cosmetics emerged as the primary culprit, accounting for 71.74 percent of these cases,” said the researchers.

A recent case series revealed an association between the use of fairness creams and NELL-1*-associated MGN. [Kidney Int 2024;105:1316-1319] “NELL-1 serves as an auto-antigen linked to both primary and secondary MGN. Examination of the skin creams revealed exceedingly high levels of Hg (>104 times the permissible limit of 1 ppm),” they noted.

One study reported MCD in all four patients after using Hg-containing fairness creams for 2–6 months. Following treatment, all had complete remission of proteinuria within 1–9 months, blood Hg levels normalized within 1–7 months, but urine Hg levels took 9–16 months to normalize. The patients were treated with either chelation therapy with D-penicillamine, steroids, and discontinuation of the creams. [Clin Nephrol 2013;79:326-329]

Treatment, prognosis

According to the researchers, chelation therapy and stopping the exposure to Hg are the cornerstones of treatment in this setting. Without chelation, it might take a while for patients to achieve remission, while proteinuria and kidney function impairment may persist.

“Although chelation might be insufficient as a standalone treatment for Hg-induced nephrotic syndrome … glucocorticoids should not be recommended as first-line treatment,” they noted. “Their use should be reserved for cases wherein chelation therapy failed to alleviate severe/refractory nephrotic syndrome, or for patients with severe clinical characteristics such as renal dysfunction, severe hypoalbuminaemia, and oedema.”

Prognosis is generally favourable, with high remission rates achieved with chelation therapy alone. Complete remission may also be achieved with additional glucocorticosteroids and immunosuppressants. Relapse was only reported in cases of Hg re-exposure, they noted.

Other substances to take note of

There is evidence reporting high concentrations of heavy metals such as nickel, lead, and chromium in some sunblock creams, elevated levels of iron in lipstick products, and maximum levels of cadmium in lotions. [Saudi Pharma J 2020;28:779-790]

“Studies have also shown elevated levels of urinary biomarkers for potentially toxic elements in women who are occupationally exposed to cosmetics. The levels of arsenic and cadmium biomarkers showed a strong and significant positive correlation with kidney damage markers, including uKIM-1** and uTIMP-1***. The presence of such heavy metals in cosmetics poses a latent threat to consumers of all demographics,” the researchers said.

Chronic lead exposure can lead to anaemia, hypertension, cardiovascular disease, immune deficiency, as well as cognitive deficits, learning disabilities, and memory loss. [Environ Anal Health Toxicol 2022;37:e2022007-0] Arsenic may disrupt cellular processes and cause kidney damage, neurotoxicity, and even cancer, while cadmium toxicity may lead to tubular and glomerular damage. [Biomolecules 2021;11:1575]

The pursuit of beauty comes with risks

“Fairness creams have deeply embedded themselves in global society, driven by a pervasive obsession with lighter skin tones as a symbol of beauty. This widespread use reflects deeply rooted cultural beliefs and social norms, despite the significant health risks associated with these products,” said the researchers.

They underlined the urgency of this topic as many individuals continue to succumb to cultural beauty standards. This review underscores the need for global awareness, stricter regulation, and public education, as continued exposure to fairness creams is not just a threat to the kidneys, but to overall health as well.

The 1996 ‘Crema de Belleza-Manning’ fiasco, wherein an alarmingly high level of Hg was detected within the cream, also underpins the need for rigorous regulatory oversight on cosmetic ingredients. [MMWR Morb Mortal Wkly Rep 1996;45:400-403] Despite the ban on Hg in cosmetics in several countries and the permissible limit of 1 ppm (1 mg/kg) for skin lightening products as per the Minamata convention, many products on the market still contain excessive Hg concentrations. [Environ Health Perspect 2013;121:A304-A309] In one study, all five fairness creams evaluated had >10,000 ppm of Hg. [Kidney Int 2024;105:1316-1319]

“By addressing the global impact of these harmful practices, we call attention to the urgent need for increased awareness among the general population and policymakers about the potential health risks posed by using skin-whitening creams,” the researchers said.

There is also a need for large, multicentre, long-term studies as current evidence linking cosmetic agents to glomerular diseases are small studies or those with short-term follow-up.

At the clinical level, the investigators reiterated the need for clinicians to “remain alert to the possibility of heavy metal toxicity in patients with new-onset proteinuria and should specifically inquire about the use of skin-lightening products.”