Sunscreen may not prevent skin cancer

High factor sun creams do not provide total protection against the deadliest form of skin cancer, new research suggests.

A study by Cancer Research UK found that while high factor sun cream can reduce damage caused by the sun and slow the onset of malignant melanoma, it does not offer complete protection.

It proves public health campaigns right to promote a combination of sun protection methods, such as hats and shade, as well as sun creams, scientists said.

During the study, mice predisposed to melanoma took only around 30% longer to develop cancer when coated in a sun protection factor (SPF) 50 sun cream than those which were not.

The research, published in the scientific journal Nature, showed that ultraviolet (UV) light directly damages deoxyribonucleic acid (DNA) in the skin’s pigment cells, increasing the chance of developing the disease.

The Irish Cancer Society’s head of promotion, Kevin O’Hagan, said the latest research showed sunscreens should not be solely relied on to protect skin.

Mr O’Hagan said the ICS had always advocated that using sunscreen alone was not enough to protect skin from UV damage.

“People often make the mistake of assuming that they can spend longer periods of time in the sun after applying sunscreen which increases their overall exposure to damaging UV rays,” he said.

Mr O’Hagan said skin cancer cases in Ireland had reached 10,000 annually.

He pointed out that, traditionally, people who worked outdoors were more at risk of non-melanoma skin cancer but in recent years this trend had changed.

“City dwellers, with intermittent sun exposure, are now more at risk from sunburn and greater numbers are presenting to their doctor with skin cancer each year,” he said.

“When people think of sunburn many only think of raw, peeling and blistering skin but any redness caused by the sun is sunburn and increases skin cancer risk.”

Mr O’Hagan said the good news was that skin cancer could be prevented in nine out of 10 cases by protecting the skin from harmful UV rays.

Sun smart

- Seek shade when UV rays are at their strongest — between 11am and 3pm.

- Cover up by wearing a shirt with a collar and long shorts. Also, wear a hat that gives shade to the face, neck, and ears.

- Wear wrap-around sunglasses to make sure they give UV protection.

- Use sunscreen with SPF 15 (SPF30 for children) or higher and UVA protection 20 minutes before going outside and reapply every two hours — more often if swimming or perspiring.

- Keep babies under six months out of the sun. If the UV Index is three or higher, it is important to protect the skin when outdoors by following the SunSmart Code.