Extrinsic ageing explained
There are a number of external factors that affect the skin and cause signs and symptoms of premature ageing. While most premature ageing is caused by over-exposure to the sun’s UV rays, there are additional, contributing factors2. For example, other atmospheric factors such as air pollution, visible light and infrared radiation (IR)3,4,5. Lifestyle choices can also significantly contribute to skin ageing; smoking, chronic stress and excessive alcohol consumption lead to older looking skin.
The most common signs of extrinsic ageing are thinning of the skin, laxity, fragility and the increased appearance of wrinkles. Sun exposure can also lead to pigmentation or sun spots and accentuate premature wrinkling.
How does UV light cause skin ageing?
There are two types of UV radiation from the sun that penetrate our atmosphere and are damaging to skin health:
UVA rays can be thought of as 'ageing rays'. They account for the majority of UV radiation reaching the earth and are consistently strong throughout the year. They have chronic effects on the skin and are responsible for the appearance of skin wrinkling, discolouration, and loss of elasticity.
UVB rays can be thought of as 'burning rays'. UVB rays are stronger in the summer and at specific times of the day, causing sunburns that peak between 6 – 24 hours after exposure. They do not penetrate skin as deeply as UVA rays, but are just as dangerous to skin health. SPF (sun protection factor) rating relates to UVB rays and the protection the formula offers against them.
UV-induced ageing happens due to the creation of free radicals and reactive oxygen species (ROS), which cause oxidative stress and damage to the proteins and cells that form the skin. Free radicals can also have a disrupting effect on numerous cellular processes that help keep the skin looking young and healthy.
Excessive exposure to UV rays does not only cause the aesthetic effects of skin ageing such as wrinkling, sagging and laxity, but also accounts for many clinically reported skin conditions, including skin cancer6.
How does visible light cause skin ageing?
Visible light has the ability to penetrate to the dermis. The rays can cause dermatological conditions and contribute to skin ageing as a result of oxidative stress. Research has shown that the generation of free radicals from oxidative stress was higher after visible light exposure7. These free radicals had an inflammatory effect causing impaired cellular functioning and a deterioration in skin health. Long-term exposure to visible light can often result in pigmentation and skin damage6.
How does ozone pollution cause skin ageing?
Ozone, an air pollutant at ground level, is considered one of the most toxic environmental stressors to which the skin is exposed. The skin, as the body’s external barrier to pollutants, is one of the most susceptible areas when it comes to the oxidative damaging effect of ozone6. Ozone pollution only comes from ground level ozone and is created between sunlight and chemical reactions found in automobile emissions and chemicals found in household and commercial cleaning products.
Although ozone cannot penetrate the skin, the damage it induces is primarily a result of its ability to induce oxidative stress, whilst chronic exposure also leads to a depletion of skin-saving antioxidants. Through the induction of oxidative stress and the reduction of antioxidants, ozone pollution encourages a stress response in the skin, bringing disruption to the skin’s normal functioning8.
How does IR radiation cause ageing?
Although current knowledge of the effects of IR radiation on skin ageing is limited, it has been shown that exposure to IR radiation causes a significant decrease in the production of antioxidants in the skin and can cause a reduction in collagen synthesis, particularly in lightly pigmented skin. Similarly, frequent or long-term exposure to IR can cause significant skin ageing and thermal burns, making the skin appear red and puffy9.
Which products can help to protect against extrinsic ageing?
Products with antioxidants and SPF are essential in protecting against extrinsic ageing. Though the skin contains a powerful antioxidant defence system, applying products such as Resveratrol B E, Phloretin CF and C E Ferulic, help boost the body’s natural production of antioxidants and combat the signs of age-related skin deterioration. Applying antioxidants can help the skin enhance its natural self-repair system6.
Antioxidant formulations containing vitamin C, such as SkinCeuticals’ Phloretin CF and C E Ferulic, provide advanced protection against environmental damage, neutralise free radicals and are especially effective against the harmful effects of ozone. Vitamin C also suppresses the damaging effects of UV radiation.
Similarly, using products with UV protection and SPF can help protect against the dangers of sun and UV exposure. A good mineral filter SPF, such as titanium dioxide, used across SkinCeuticals’ mineral SPF range, provides a non-chemical protective barrier against sun damage and the ageing effects of UV rays.
Want to find out more about the different types of ageing and our recommended anti-ageing skincare routine?
Discover expert anti-ageing advice here:
- Tips For Achieving Youthful Skin Overnight
- A Dermatologist's Tips On 'Skincare Through The Ages
- Top 5 Anti-Ageing Cosmetic Treatments
This article is intended as general information only. You should seek advice from a professional before starting any new regimen or course of conduct.
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2 Pinnell SR. Cutaneous photodamage, oxidative stress, and topical antioxidant protection. J Am Acad Dermatol. 2003;48:1-19.
3 Kousha T, Valacchi G. The air quality health index and emergency department visits for urticaria in Windsor, Canada. J Toxicol Environ Health A. 2015;78:524-533.
4 Kollias N, Bager A. An experimental study of the changes in pigmentation in human skin in vivo with visible and near infrared light. Photochem Photobiol. 1984;39:651-659.
5 Schroeder P, Calles C, Benesova T, Macaluso F, Krutmann J. Photoprotection beyond ultraviolet radiation–effective sun protection has to include protection against infrared A radiation-induced skin damage. Skin Pharmacol Physiol. 2010;23:15-17.
6 McDaniel D, Farris P, Valacchi G. Atmospheric skin aging – Contributors and inhibitors. Journal of Cosmetic Dermatology 2017
7 Liebel F, Kaur S, Ruvolo E, Kollias N, Southall MD. Irradiation of skin with visible light induces reactive oxygen species and matrixdegrading enzymes. J Invest Dermatol. 2012;132:1901-1907.
8 Valacchi G, van der Vliet A, Schock BC, et al. Ozone exposure activates oxidative stress responses in murine skin. Toxicology. 2002;179:163-170.
9 Cho S, Shin MH, Kim YK, et al. Effects of infrared radiation and heat on human skin aging in vivo. J Investg Dmermatol 2009;14:15-19.