Obvious signs of ageing include:
Exposure to the following internal/external factors are responsible for the signs of ageing:
This is the main cause of skin ageing so has more detail below;
Pollutants such as polycyclic aromatic hydrocarbons (chemicals that are released when burning coal, gasoline, trash or tobacco), volatile organic compounds (present in paints, coatings and car exhausts), oxides, particulate matter, ozone and cigarette smoke cause significant damage to the skin through oxidative stress.
Smoking increases free radicals in the skin, speeding up the normal ageing process causing facial wrinkling, particularly around the mouth, upper lip and eyes. Nicotine in cigarettes causes narrowing of the blood vessels thus impairing blood flow to the outer layers of the skin thus restricting delivery of oxygen and important nutrients, such as vitamin A to the skin resulting in dry, dull skin.
Many of the chemicals in tobacco smoke also damage collagen and elastin. As a result, skin begins to sag and wrinkle prematurely.
Evidence suggests that heat exposure may play an important role in premature skin ageing. Repetitive and prolonged heat exposure causes protective antioxidant levels in the skin to drop and collagen to breakdown that can accelerate the rate of skin ageing. Cold weather causes the skin to become dry and dehydrated, leading to enhanced appearance of surface lines and wrinkles.
It is thought that a diet rich in anti-oxidants may delay skin ageing. Higher vitamin C intake has been associated with a lower likelihood of wrinkles, while consuming too much sugar, fat and carbohydrates has been associated with a higher likelihood for a wrinkled appearance. A diet rich in fruits and vegetables is essential for overall and skin health.
Stress affects your mind, body and your skin. Research has shown stress can cause wrinkles and chronic stress can contribute to premature ageing. The "fight or flight" response induces the release of cortisol which breaks down collagen in your skin. The more stressed a person is, the more cortisol is produced and the body is unable to keep up with rebuilding elastin and collagen.
Sleep is a time for skin to heal, renew and eliminate toxins. There is evidence that those who are sleep deprived exhibit more signs of skin ageing including fine lines, uneven pigmentation and reduced skin elasticity.
Exposure to the sun's rays is the main cause of skin ageing via a process known as oxidative stress and inflammation. Sunscreens are useful for the prevention of skin cancer and early signs of ageing when used in combination with sun exposure limitation and wearing protective clothing.
Sunlight consists of two types of rays—UVA rays and UVB rays—both lead to premature ageing, wrinkles and the development of skin cancer.
UVA rays are able to pass through glass and are mainly responsible for the development of wrinkles and age spots.
UVB rays cause sunburn and are blocked by window glass.
80% of facial ageing is thought to be secondary to daily, chronic sun exposure.
It's not all doom and gloom though, there are ways to reduce premature skin ageing, read this article for more information.