The process of skin aging has been divided into two categories:

1. Intrinsic – Natural aging is caused by changes in the elasticity of the skin over time. 
2. Extrinsic – Primarily a result of exposure to solar radiation (photoaging). UV exposure causes physical changes to the skin due to alterations that occur in the connective tissue via the formation of lipid peroxides, cell contents, enzymes, and reactive oxygen species (ROS)

Intrinsic Ageing is controlled by your body’s own biological clock. The production of collagen within the dermis slows down and elastin has less ‘spring’, the turnover of new skin cells takes longer as does the shedding of dead skin cells; these changes start as early as your twenties but take years to be visible in the appearance of your skin.

These two factors together lead to cumulative structural, physiological and progressive alterations to each skin layer and ultimately the appearance of the skin itself.

What else can cause wrinkles?

Cigarette Smoke
It contains thousands of chemical substances like carcinogens – a substance capable of causing cancer in living tissue. Oxygen radical forming substances such as catechol – a substance known to cause eczema dermatitis. Skin Effects: Chemical substances from cigarette smoke activate transepidermal water loss, degeneration of connective tissue, cause deeper wrinkling, premature facial skin aging in smokers along with orange-purple skin discolouration. Free radicals from cigarette smoke are associated with oxidative stress resulting in lipid cell damage. A higher occurrence of acne among smokers and a correlation between the severity of acne and the number of smoked cigarettes has been shown also cigarette smoke is associated with psoriasis. 

Skin ageing is a complex process involving several environmental factors, most important of which is UV light from sun. Along with other factors about 80% of the facial wrinkling is considered due to the UV light. UV generates reactive oxygen species, and consequently triggers several mechanisms leading to collagen deficiency and eventually skin wrinkling 

(Fischer et al., 1997)

Ultraviolet Radiation (UV)
UV Radiation covers UVA UVB and UVC – 95% of the solar radiation that reaches the earth’s surface is UVA and UVB. Most UVC is absorbed by the Ozone layer and oxygen in the atmosphere. Skin Effects: UVA has been linked to skin photoaging and to the development of skin cancers. UVA penetrates deeply into the basal layer of the epidermis and dermal fibroblasts. UVB has also been linked to the development of skin cancers. UVB is largely absorbed by epidermal cellular components.

Pollution
Volatile Organic Compounds (VOCs) –These are emissions from using organic solvents found in paints, varnishes, environmental tobacco smoke, stored fuels, and exhausts from cars, and from Industrial Factories – SMOG. Skin Effects: can cause both inflammatory and allergic reactions resulting in atopic dermatitis or eczema.

Oxides – Are emitted mainly from mobile and stationary combustion sources: Industrial Power Plants and exhaust fumes, also from natural sources like volcanic activity and forest fires. Skin Effects: The generation of free radicals that may oxidize amino acids in tissue proteins and initiate lipid cell damage of polyunsaturated fatty acids, resulting in dermatitis and atopic eczema [when exposed to high levels of traffic-related air pollution.]

Particulate Matter (PM) – These are air pollutants that are made up of different mixtures and sizes of particles resulting from Factories, Automobiles, Power Plants, Waste Incinerators, Fires, and natural windblown dust. Skin Effects: Particles in the nanosize range, especially those from traffic sources, are considered among the most harmful components causing oxidative stress in skin meaning premature aging – pigment spots and wrinkles.

Stress 
Cortisol, the primary stress hormone, has been known to break down the collagen in your skin, among other things. The more stressed you are, the more cortisol your body produces. Eventually, your skin cells won’t be able to naturally rebuild the elastin and collagen as well as they used to.

Study – a small but significant study in 2004 showed the first link between chronic stress and aging. This study showed that telomeres (structures at the ends of chromosomes that shorten with aging) also shorten prematurely in people experiencing long-term psychological stress, in effect, prematurely “aging” the cells. Since then, subsequent studies have confirmed the finding that shortened telomeres are associated with psychological stress.

Diet 
The primary mechanism that drives the development of a wrinkle is called glycation. When sugar is ingested it goes through a process called glycation, which involves binding to different proteins in our bodies, these proteins include collagen and elastin. After a series of chemical reactions, this binding forms an end product known as an AGE (advanced glycation end product). The production of AGEs is what damages the surface of the skin by weakening collagen and elastin and will lead to the appearance of fine lines and wrinkles. Glycation also produces toxic products that further cause premature aging.

Moisture levels
The lack of moisture in our skin plays a major role in the development of wrinkles, particularly micro-wrinkles at the surface which can become much deeper, larger, and more visible when the outermost skin layer – the stratum corneum (a 10-20 micrometres assembly of dead cells) becomes dryer. This can happen due to dryer environmental conditions caused by heating, cooling and long-haul flights.

CONCLUSION – Intrinsic skin ageing is thought by some researchers to contribute to around 3% of the process of skin ageing. This is great news as we do have control over the lifestyle choices we make which massively affect both the health and appearance of our skin. There are  seven simple steps we can take in the prevention of the early signs of ageing: 

1. Avoid smoking or being exposed to smoke
2. Using a broad-spectrum zinc-based sunscreen
3. Cutting down or cutting out sugar consumption
4. Keeping our skin moisturized
5. Reducing stress levels
6. Proper cleansing of your skin at the end of the day to remove skin pollution, makeup, and SPF
7. Application of skincare products with active antioxidant and anti-inflammation properties.

Until next time, be human, be kind, be you

Much love Gabrielle

REFERENCES

• The potential of herbs in skin protection from ultraviolet radiation – Korać, R. R., & Khambholja, K. M. (2011). The potential of herbs in skin protection from ultraviolet radiation. Pharmacognosy Reviews, 5(10), 164–173. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3263051/
• Air pollution and the skin –http://journal.frontiersin.org/article/10.3389/fenvs.2014.00011/full 
• The University of Southampton. (2018, February 28). Going skin deep to explore what causes wrinkles. ScienceDaily.
  https://www.sciencedaily.com/releases/2018/02/180228133958.htm
• Gkogkolou P, Böhm M. Advanced glycation end products: Key players in skin aging? Dermato-endocrinology. 2012;4(3):259-270. doi:10.4161/derm.22028.
  https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3583887/