Two studies about the effects the sun has on aging skin have been in the news recently. The first is quite impressive. Look at this photo.
This man is a trucker who had driven his delivery vehicle for 28 years. The photo shows the skin changes to the side of his face that was exposed to the sun without sunscreen. The window of his vehicle was closed but the glass did not prevent the UV rays from damaging the skin on that side of his face.
His doctors diagnosed him with unilateral dermatoheliosis (photoaging from chronic UV exposure). He was told to use sun protection and topical retinoids as well as have periodic monitoring for skin cancer.
The other study also demonstrates that lack of using daily sunscreen contributes to skin aging. White participants aged 25-55 from an area north of Sydney, Australia were monitored for over four and a half years.
The majority of participants were fair complected and already had sun avoidance behaviors. Most intermittently used sunscreen and two-thirds wore hats regularly when out in the sun.
The 900 participants were divided into two groups. The first group was told to continue their usual sun avoidance activity. The second group was asked to use broad-spectrum sunscreen of SPF 15 every day in the morning and after exercise or bathing.
Researchers took silicon casts of the skin on their left hand before and after the study ended to compare them. The casts were taken by having the participant grasp a cardboard tube to stretch the skin prior to casting.
Typically a skin biopsy is used to measure elastin levels in the skin but the casting technique was determined to give similar information. The researchers did not know the identity of the person whose skin they were examining. The skin's appearance was rated on a scale from 0 to 6.
A 6 was given for severely aged skin, meaning no elastin and deep lines. At the start of the study the average level of aging was 4, for both groups indicating they already had moderate aging.