Skin whitening
Skin whitening, also known as skin lightening and skin bleaching, is the practice of using chemical substances in an attempt to lighten the skin or provide an even skin color by reducing the melanin concentration in the skin. Several chemicals have been shown to be effective in skin whitening, while some have proven to be toxic or have questionable safety profiles. This includes mercury compounds which may cause neurological problems and kidney problems.[1]
Skin whitening
Skin lightening, brightening, depigmentation, bleaching
In a number of African countries, between 25 and 80% of women regularly use skin whitening products.[2] In Asia, this number is around 40%.[2] In India, specifically, over half of the skin care products are sold to whiten skin.[3][2] In Pakistan, where skin lightening products are popular, creams have been found to contain toxic levels of hydroquinone and mercury.[4][5]
Efforts to lighten the skin date back to at least the 16th century in Asia.[6] While a number of agents—such as kojic acid and alpha hydroxy acid—are allowed in cosmetics in Europe, a number of others such as hydroquinone and tretinoin are not.[6] While some countries do not allow mercury compounds in cosmetics, others still do, and they can be purchased online.[2]
Use[edit]
Areas of increased pigmentation such as moles may be depigmented to match the surrounding skin. Effective agents for specific areas include corticosteroids, tretinoin, and hydroquinone.[6] These agents, however, are not allowed in cosmetics in Europe due to concerns about side effects.[6] Attempts to whiten large areas of skin may also be carried out by certain cultures.[6] This may be done for reasons of appearance, politics, or economics.[6]
Skin whiteners can help achieve lighter skin tones, but many of them contain harmful ingredients like the steroid clobetasol propionate, inorganic mercury (mercuric chloride or amalgamated mercury), glutathione (an antioxidant traditionally used in cancer treatment), and the organic compound hydroquinone.[7] Skin lighteners' main health risks are linked to (i) The overuse of topical clobetasol, which can cause systemic steroid effects from daily usage, especially on broad skin regions; and (ii) concealed mercury content, which can lead to mercury poisoning depending on individual susceptibility. Many skin whiteners contain a toxic form of mercury as the active ingredient.[2] Their use, therefore, may harm a person's health and is illegal in many countries.[2][8]
Hydroquinone is a commonly used agent in skin whiteners, though the European Union banned it from cosmetics in 2000.[9] It works by decreasing melanin production.[9] Tretinoin, also known as all-trans retinoic acid, may be used to whiten specific areas.[6] It may be used in combination with steroids and hydroquinone.[6]
Alpha hydroxy acid (AHA) is also used as a skin bleacher, but its biochemical mechanism is unclear.[6] Side effects may include sun sensitivity, skin redness, thickening, or itching.[6] Low concentrations may be used in cosmetics.[6] Kojic acid has been found to be an effective lightener in some studies and is also allowed to be used in cosmetics.[6] Side effects, however, include redness and eczema.[6]
Glutathione is the most common agent taken by mouth in an attempt to whiten the skin.[10] It may also be used as a cream.[10] It is an antioxidant normally made by the body.[10] Whether or not it actually works is unclear as of 2019.[11] Due to side effects that may result from intravenous use, the government of the Philippines recommends against such use.[12]
One 2017 review found tentative evidence of benefit of tranexamic acid in melasma,[13] while another 2017 review found that evidence to support its use was insufficient.[14] Azelaic acid may be a second-line option for melasma.[15] A number of types of laser treatments have been used in melasma with some evidence of benefit.[16] Reoccurrence, however, is common, and certain types of lasers can result in more pigmentation.[16]
Side effects[edit]
Skin lightening creams have commonly contained mercury, hydroquinone, and corticosteroids.[17] Because these compounds can induce both superficial and internal side effects, they are illegal to use and market in multiple nations.[17][18] However, various chemical studies indicate that these compounds continue to be used in sold cosmetic products, though they are not explicitly declared as ingredients.[19][1]
Prolonged usage of mercury-based products can ultimately discolor the skin, as mercury will accumulate within the dermis.[20] Mercury toxicity can cause acute symptoms such as pneumonitis and gastric irritation.[20] However, according to a study by Antoine Mahé and his colleagues, mercurial compounds can also contribute to long-term renal and neurological complications, the latter of which includes insomnia, memory loss, and irritability.[1]
Other studies have explored the impact of hydroquinone exposure on health.[17] Hydroquinone rapidly absorbs into the body via dermal contact; long-term usage has been found to cause nephrotoxicity and benzene-induced leukemia in the bone marrow.[21] A study by Pascal del Giudice and Pinier Yves indicated that hydroquinone usage is strongly correlated with the development of ochronosis, cataracts, patchy depigmentation, and contact dermatitis.[17] Ochronosis can subsequently lead to lesions and squamous cell carcinomas.[20] While hydroquinone has not been officially classified as a carcinogen, it can metabolize into carcinogenic derivatives and induce genetic changes in the form of DNA damages.[1][21]
Additionally, corticosteroids have become some of the most commonly incorporated lightening agents.[20] Long-term usage over large areas of skin may promote percutaneous absorption, which can produce complications such as skin atrophy and fragility, glaucoma, cataracts, edemas, osteoporosis, menstrual irregularities, and growth suppression.[20] A 2000 study performed in Dakar, Senegal, indicated that chronic usage of skin lighteners was a risk factor for hypertension and diabetes.[1]
Chemically lightened skin is also more highly susceptible to sun damage and dermal infection.[20][1] Long-term users of skin bleachers can easily develop fungal infections and viral warts.[20] Pregnant users may also experience health complications for both them and their children.[20][1]
Rate of usage[edit]
According to Yetunde Mercy Olumide, advertisements for skin lighteners often present their products as stepping stones to attain greater social capital.[22] For example, representatives of India's Glow & Lovely cosmetics asserted that their products allowed for socioeconomic mobility, akin to education.[22]
Skin whiteners typically range widely in pricing; Olumide attributes this to the desire to portray whitening as financially accessible to all.[22] These products are marketed to both men and women, though studies indicate that, in Africa, women use skin bleachers more than men do.[22][23] A study by Lester Davids and his colleagues indicated that nations in Africa present high rates of usage for skin bleachers.[24] Though many products have been banned due to toxic chemical compositions, Davids found that regulating policies are often not strictly enforced.[24]
In India, the sales of skin lightening creams in 2012 totaled around 258 tons, and in 2013 sales were about US$300 million.[25][26] By 2018, the industry for lightening cosmetics in India had achieved a net worth of nearly $180 million and an annual growth rate of 15%.[27] As of 2013, the global market for skin lighteners was projected to reach $19.8 billion by 2018 based on sales growth primarily in Africa, Asia, and the Middle East.[28]
In the United Kingdom, many skin whiteners are illegal due to possible adverse effects. Such products are frequently still sold even after shops have been prosecuted. Trading standards departments lack the resources to deal with the problem effectively.[29]
Motivations[edit]
Historian Evelyn Nakano Glenn attributes sensitivities to skin tone among African Americans to the history of slavery.[30] Lighter-skinned African Americans were perceived to be more intelligent and skilled than dark-skinned African Americans, who were relegated to more physically taxing, manual labor.[30]
Studies have additionally linked paler skin to achieving various forms of social standing and mobility.[31][32][18] A study by Kelly Lewis and her colleagues found that, in Tanzania, residents choose to bleach their skin to appear more European and impress peers and potential partners.[32] Both advertisements and consumers have suggested that whiter skin can enhance individual sexual attractiveness.[33] Sociologist Margaret Hunter noted the influence of mass-marketing and celebrity culture emphasizing whiteness as an ideal of beauty.[31] A study by Itisha Nagar also revealed that lighter skin tones in both men and women in India improved their prospects for marriage.[27]
Skin whitening is common throughout Asia. In South Korea, light skin is considered an ideal of beauty, and most South Koreans believe that having paler skin is the only way to look beautiful.[34] In South Korea, skin whitening is a multi-billion-dollar industry.[35] The K-pop and K-drama industries are saturated with fair-skinned celebrities, some of whom serve as brand ambassadors and beauty ideals.[34] The increasing popularity of K-pop and K-beauty has driven the skin-whitening trend elsewhere in Asia, especially in poorer countries like Thailand, where many have begun to use unsafe skin-whitening products.[36] In Nepal, cultural influence from Bollywood, which prominently features lighter skinned lead actors, has been linked to the use of skin whitening creams among some darker-skinned men.[37]
Other motivations for skin whitening include desiring softer skin and wanting to conceal discolorations arising from pimples, rashes, or chronic skin conditions.[32] Individuals with depigmenting conditions such as vitiligo have also been known to lighten their skin to achieve an even skin tone.[38]
Health hazards[edit]
Several chemical substances have been found to be effective in skin whitening, but some have been proven or suspected to be toxic. This includes compounds containing mercury, which can cause neurological and kidney problems.[94] These products also contain collagen, which can be harmful to the skin. It is present in day creams and beauty masks. Collagen is an insoluble fibrous protein that is too large to penetrate the skin, thus it can clog pores.[95]
The use of these products can be hazardous to health, potentially causing acne, stretch marks, skin cancer,[96] hypertension, or diabetes, especially when the product contains hydroquinone,[97] mercury, cortisone, or vitamin A.[98] Allergic reactions or undesirable effects such as uneven hyperpigmentation or patchy depigmentation can also occur.[99]
Among the ingredients, hydroquinone is also commonly found and is responsible for multiple side effects. It can interfere with the reagents used in capillary blood glucose meters, artificially raising blood glucose levels.[100]
In 1997, in Paris, the French police dismantled a network involved in the illegal trafficking of skin lightening products, primarily targeting Congolese migrants. Such products represent a significant market despite their health risks. Users resort to preparations containing mercury or bleach, or products containing corticosteroids or quinine. The Saint-Louis Hospital in Paris had to establish a specialized department to deal with the skin disorders caused by skin bleaching.[101][102]
The World Health Organization (WHO) has noted the significant presence of inorganic mercury added to skin lightening products, which is known to be associated with skin cancer.[90 1]