Aged skin tells an unhealthy tale

Published on Monday 21 December 2009 21:46

SMOKING and being overweight are key factors that speed up the ageing of skin by sunlight, research has shown.

To examine the environmental causes of skin ageing, scientists in the US studied 65 pairs of identical and non-identical twins.

They found that higher levels of skin damage linked to exposure to sunlight were associated with heavier body weight and smoking.

Drinking alcohol, on the other hand, appeared to offer protection against sun damage.

Since only identical twins share the same genes, twin studies can be used to screen out genetic traits. Influences that affect one of a pair of identical twins but not the other are likely to be environmental.

Long-term exposure to the sun causes physical and structural changes to the skin that result in "photodamage", said the researchers writing in the journal Archives of Dermatology.

Where normal skin ageing was characterised by fine wrinkles and skin growths, photodamage produced coarsely wrinkled skin, "age spots" or loss of pigment and dilated blood vessels on the face.

Up to 40 per cent of ageing-related changes were due to non-genetic factors, said the scientists.

A total of 130 individuals completed surveys giving information about skin type, history of skin cancer, smoking and drinking habits, and weight.

Each participant was awarded a "photodamage score" based on characteristics such as wrinkling and alterations in pigmentation.

The study was conducted in Twinsburg, Ohio, where every year twins gather for the annual Twin Days Festival.

The authors, led by Kathryn Martires, from Case Western Reserve School of Medicine in Cleveland, wrote:

"Among the most important results is that a history of skin cancer and photodamage are highly associated in a population that shares genetic commonalties.

"The relationships found between smoking, weight, sunscreen use, skin cancer and photodamage in these twin pairs may help to motivate the reduction of risky behaviours."