Combine the internal ageing with external ageing and you have a great probably of speeding up the aging process prematurely. The sun is the major cause of premature aging.
Sun screen. Avoiding the sun just a few minutes a day can cause a positive impact on how much premature skin aging may occur. Minor changes in skin appearance like spotted complexion, freckles, age sports. Even more sever changes can occur like leathery rough skin, loose skin and even skin cancer.
The severity of skin change depends on the length of exposure over the years and the persons skin color. The actual process of change that is occurring in the skin is happening in the second layer of skin. UV light breaks down collagen and prevents new collagen from growing.
Airborne pollutants also contribute to signs of aging. Dirt and chemical particles in the air create a layer of cover over the skin and prevent oxygen from entering the cells to be used as a nutrient.
Now add cigarette smoking on top of those two and you have the trifecta of skin ageing. Smoking causes biochemical changes in the body that accelerates ageing. If they live long enough to view the changes in their skin, research shows that smokers will develop deep wrinkled leathery skin. This can even be a weird yellowish color. Interestingly, stopping smoking can reduce the visible signs of aging given enough time.