Skin ageing is a fact of life, however its progression is easily controllable and preventable by using the right diet, skin and lifestyle practises. Prematurely aged skin ages a person beyond their years however well cared for skin visually protects, nurtures and in some cases restores youth.
Skin ageing may be unavoidable however it is not uncontrollable.
Skin aged past its years is often referred to as prematurely aged skin. People of all ages may experience prematurely aged skin, however mature skin types visibly show the effects most prominently. Skin damage is frequently accumulated during youth, when effects are not visible. This fact causes many people to develop a relaxed attitude to skincare. However a preventative skin ageing routine is most effective when used on already youthful skin.
While UV light is a well-known cause of skin ageing. Newly researched environmental factors are emerging as prominent causes, stressors and promotors.
Pollution and skin ageing
Air pollution is a rising environmental concern. While government initiatives such as Australia’s National Clean Air Agreement help decrease exposure and resulting health conditions, pollutants such as ground-level ozone, nitrogen dioxide and sulphur dioxide are not yet standardly reported and therefore measurable1. The control of national and global pollution levels is a work-in-progress.
Pollution is a known cause of physical stress. Living in areas with a high level of particulate matter/airborne pollution is known to increase a person’s risk of asthma2, cardiovascular disease3 and skin cancer4. This known correlation has therefore raised the question, ‘Can air pollution age skin prematurely?’ Air pollution is known to oxidatively stress and age individual organs such as the heart and lungs, however skin is the largest of all human organs. If airborne pollution has a detrimental effect when inhaled, it must have a similar oxidative and detrimental effect when deposited on top of skin.
How air pollution ages skin
Since it was first hypothesised air borne pollution has a pro-ageing effect on skin, study upon study has validated this concept. A landmark 2010 study which assessed the skin health of 400 Caucasian women aged 70-80 years old, positively correlated living in an area of high pollution with skin ageing, specifically signs of age or liver spots. This body of research demonstrated living in an area with increased soot (0.5×10-5/m) and particulate pollution (475kg/year/Km2) resulted in a 20% increase of age spots specifically on a person’s forehead and cheeks5. Higher incidences of pigment spots or age spots were also correlated with living close to a busy road.
What are age spots?
Age spots are a visible sign of skin damage and skin ageing. Skin which has significant exposure to pro-ageing factors, has a high incidence of age spots. Therefore its association with other visible effects of ageing e.g. fine lines, development of coarse wrinkles, and loss of elasticity is also expected.
Age spots are formed from the same skin processes which cause skin to tan. Melanin, the pigment responsible for all human skin colourations, is thought to help skin protect itself6. Although the function of melanin is not fully understood, its expression is increased during sun exposure, after skin damage e.g. post inflammatory hyperpigmentation (common in acne sufferers) and as a consequence of exposure to pollution. All 3 factors find commonality in oxidative damage.
What causes age spots?
The formation of melanin requires 3 distinct entities, melanocytes, the type of cell responsible for producing melanin, melanosomes, the distinct entity within melanocytes which synthesis, store and transport melanin and the tyrosinase enzyme, the rate limiting step for melanin synthesis.
When an external stressor triggers the production of melanin, it is the melanosomes within melanocyte cells which become active. The tyrosinase enzyme is also located here. The tyrosinase enzyme is crucial for melanin production and therefore it is often the target of lightening and brightening skin treatments. When the tyrosinase enzyme is active or upregulated by external factors, melanin expression increases. When skin is disproportionately exposed to oxidative triggers, melanin synthesis may be disproportionately activated, therefore resulting in age spots.
Specific pollutants present within air born pollution have been shown to regulate skins production of melanin. These pollutants are present because of road traffic, volcanic reactions, industrial activities and more. Dioxins are one such type of pollutant. Their presence is noted in both soil and air. Out of the 400 dioxin species known, 2, 3, 7, 8-tetrachlorodibenzoparadioxin (TCDD) is considered the most toxic7. Researchers exposing human melanocytes to small concentrations of TCDD for 5 days have showed significant upregulation of the tyrosinase enzyme accompanied by a three-fold increase in melanin production8. The same biological pathways TCDD acts upon, are also activated by ozone9, polycyclic aromatic hydrocarbons (PAHs) and other emerging pollutants10.
Small and ultrafine pollution particles are able to absorb skin damaging pollutants such as PAHs. Particulate pollution particles are defined by size, with larger varieties finding it harder to penetrate the skin barrier. However, pollution particles classified as fine particulate matter (<2.5um, PM2.5) or ultrafine particles (<100nm) are of the correct size to penetrate skin through hair follicles or pores11. This transfollicular route, matches an average pore size of 1.5um to the size of some fine particulate matter and all ultrafine particulate matter. PAHs are most often found bound to soot which research shows has a strong effect on the proliferation of age spots12.
How do you prevent age spots?
Age spots or as they are also known liver spots, are a telling sign of aged skin. They cause uneven skin tone, proliferating and darkening during sun exposure. However their incidence can be prevented and indeed sometimes treated.
In the treatment and prevention of age spots there are 2 methods;
- To use skincare practises preventing the deposition and accumulation of pollution on and into skin
- To inhibit tyrosinase activity, lightening and brightening uneven pigmentation
Prevention is always better than cure and therefore of either route, the first is most important to adopt. The best skincare practises for preventing age spots will be discussed in detail soon.
For skin types with visible age spots, skincare actives able to inhibit tyrosinase activity e.g. vitamin C or niacinamide will help lighten and brighten areas of existing damage. As tyrosinase enzyme is the rate limiting step for production of melanin, lowering of its activity, reduces skins over production of melanin deposits.
How to protect your skin from air pollution
The most natural, efficient and effective methods for preventing age spots stem from protecting skin against air pollution. Some of these steps are self-explanatory whereas others are less obvious. Protecting skin from air pollution helps prevent age spots, while also strengthening skin against signs of premature ageing.
- Prevent age spots by cleansing skin daily
The longer air pollution is left in contact with skin, the greater its effects. If particulate matter is left in contact with skin for over 48 hours, there are noticeable biological changes. When pollution particles are deposited into skin, they must overcome skin’s defensive oil based barrier. This process takes time, therefore the longer pollution particles are resident, the deeper they may penetrate. If pollution particles are swiftly removed, their pro-ageing effects are lessened and prevented.
Cleansing skin daily helps prevent the build-up and penetration of particulate matter. An appropriate cleanser will be both gentle and effective, helping remove air pollution deposits while also protecting skin’s barrier properties. Gentle, pH balanced cleansers such as the griffin+row Cleanse skin cleanser are most appropriate.
- Prevent age spots with use of BB cream or foundation
Air pollution is only able to cause significant skin damage if it is able to penetrate skin. While sat on skin’s surface its effects are limited. Therefore products which help prevent the penetration of air borne pollution, help avoid the formation of age spots. As opposed to moisturisers and serums, BB creams and foundations are designed to rest on top of skin. Using either a BB cream or foundation daily limits skin penetration of particulate matter, preventing the formation of age spots.
- Prevent age spots with daily use of sunscreen
Sunshine is a form of energy. Out of all wavelengths, UV light has the highest amount. Energy is able to speed reactions that would normally occur more slowly. For example, sunshine is a primary mediator in the formation of photochemical smog. Sunshine also enhances the production of air pollutants such as ozone. When pollution particles are deposited on and within skin, their reactivity may be promoted by exposure to UV light. UV light is a well-recognised cause of premature ageing and is already linked to the formation of solar lentigos, dark marks commonly perceived as age spots. The known impact of sunlight on formation of oxidative compounds such as reactive oxygen species and free radicals presents an interesting connection between a person’s exposure to pollution and their incidence of age spots.
The proliferation of pollution damage may be prevented by daily use of a skin friendly sunscreen. Sensitive sunscreens based on mineral compounds such as zinc oxide and titanium dioxide are most appropriate.
- Prevent age spots with regular use of emollient rich skincare
Skin is only able to defend against pollution when its barrier properties are well formed. Many of the stressors skin comes into contact with are water dissolvable and to prevent or slow their penetration, skin’s top layers are mostly oil based. As water and oil do not naturally mix, water dissolvable impurities are prevented from entering skin.
Skin’s oil based barrier is frequently assaulted by western bathing practises and is already weakened in dry, dermatitis and eczema prone skin types. Emollient rich skincare products rich in oils and butters are able to recondition skins barrier properties and replenish lost emollients. Therefore age spots may be prevented due to a newly resilient skin barrier. Emollient rich moisturisers such as the griffin+row Enrich antioxidant night cream are most appropriate.
- Prevent age spots by avoiding over washing/using gentle cleansing products
The slower air pollution is able to penetrate skin, the lower a person’s risk of developing age spots. To slow penetration of particulate matter, skin requires an effective and healthy barrier of which there are two important features. Firstly skin must retain its oil based nature, secondly skin must remain pH balanced. Many traditional cleansing products eat away layers of skin’s natural oils while also having a pH level significantly more alkaline than skins acidic biology. Therefore traditional cleansing products challenge and deplete skins protective function allowing air borne pollution to penetrate skin more quickly.
Harsh cleansing products, commonly spotted by inclusion of sodium lauryl sulphate (SLS) are key in the removal of skin’s natural oils and the perturbation of skin’s pH balance.
Gentle, SLS free, pH balanced cleansing products such as the griffin+row Cleanse skin cleanser help prevent age spots while also ensuring skin’s own barrier function remains integral. Use of hand wash and harsh shower gels should also be restricted and over cleansing avoided. Indicators of over cleansing include, dull, dry dehydrated, sensitive and tight, squeaky clean feeling skin.
References and Sources
- http://www.environment.gov.au/protection/air-quality” rel=”nofollow”>http://www.environment.gov.au/protection/air-quality
- Outdoor air pollution and asthma. Guarnieri M, Balmes JR. Lancet. 2014 May 3;383(9928):1581-92. doi: 10.1016/S0140-6736(14)60617-6
- Lee B-J, Kim B, Lee K. Air Pollution Exposure and Cardiovascular Disease. Toxicological Research. 2014;30(2):71-75. doi:10.5487/TR.2014.30.2.071.
- Air pollution and skin diseases: Adverse effects of airborne particulate matter on various skin diseases.Kim KE, Cho D, Park HJ. Life Sci. 2016 May 1;152:126-34. doi: 10.1016/j.lfs.2016.03.039. Epub 2016 Mar 25.
- Airborne particle exposure and extrinsic skin aging. Vierkötter A, Schikowski T, Ranft U, Sugiri D, Matsui M, Krämer U, Krutmann J. J Invest Dermatol. 2010 Dec;130(12):2719-26. doi: 10.1038/jid.2010.204. Epub 2010 Jul 22
- Ortonne, J.-P. (2002), Photoprotective properties of skin melanin. British Journal of Dermatology, 146: 7–10. doi:10.1046/j.1365-2133.146.s61.3.x
- Recognizing the impact of ambient air pollution on skin health. Mancebo SE, Wang SQ. J Eur Acad Dermatol Venereol. 2015 Dec;29(12):2326-32. doi: 10.1111/jdv.13250. Epub 2015 Aug 20
- Luecke S, Backlund M, Jux B, Esser C, Krutmann J, Rannug A. The aryl hydrocarbon receptor (AHR), a novel regulator of human melanogenesis. Pigment Cell Melanoma Res 2010; 23: 828–833.
- Afaq F, Zaid MA, Pelle E et al. Aryl hydrocarbon receptor is an ozone sensor in human skin. J Invest Dermatol 2009; 129: 2396–2403.
- Activation of AhR-mediated toxicity pathway by emerging pollutants polychlorinated diphenyl sulfides.Zhang J, Zhang X, Xia P, Zhang R, Wu Y, Xia J, Su G, Zhang J, Giesy JP, Wang Z, Villeneuve DL, Yu H. Chemosphere. 2016 Feb;144:1754-62. doi: 10.1016/j.chemosphere.2015.09.107
- J. Lademann, H. Schaefer, N. Otberg, A. Teichmann, U. Blume-Peytavi, W. Sterry, [Penetration of microparticles into human skin], Hautarzt 55 (2004) 1117-1119.
- Airborne particle exposure and extrinsic skin aging.Vierkötter A, Schikowski T, Ranft U, Sugiri D, Matsui M, Krämer U, Krutmann J. J Invest Dermatol. 2010 Dec;130(12):2719-26. doi: 10.1038/jid.2010.204.
- Natalia D. Magnani, Ximena M. Muresan, Giuseppe Belmonte, Franco Cervellati, Claudia Sticozzi, Alessandra Pecorelli, Clelia Miracco, Timoteo Marchini, Pablo Evelson, Giuseppe Valacchi; Skin Damage Mechanisms Related to Airborne Particulate Matter Exposure. Toxicol Sci 2016; 149 (1): 227-236. doi: 10.1093/toxsci/kfv230
- Pollution and skin: from epidemiological and mechanistic studies to clinical implications. Krutmann J, Liu W, Li L, Pan X, Crawford M, Sore G, Seite S. J Dermatol Sci. 2014 Dec;76(3):163-8. doi: 10.1016/j.jdermsci.2014.08.008. Epub 2014 Sep 16.