Ultraviolet light exposure causes the same DNA damage that leads to both a suntan and skin cancer, meaning there is no such thing as a safe tan, new research suggests.

The findings suggest that the primary way to protect against skin cancer is to avoid getting a suntan, whether from sunbathing or a tanning salon, both of which lead to UV-ray exposure.

"UVR [ultraviolet radiation] exposure represents one of the most avoidable causes of cancer risk and mortality in man," wrote Dr. David E. Fisher and colleagues from Massachusetts General Hospital.

"Whereas genetic and other factors undoubtedly contribute importantly to skin cancer risk, the role of UV is incontrovertible and efforts to confuse the public, particularly for purposes of economic gain by the indoor tanning industry, should be vigorously combated for the public health."

The new suntan research is published in a series of papers in Pigment Cell & Melanoma Research, the journal of The International Federation of Pigment Cell Societies and the Society for Melanoma Research.

Tanning beds are popular, particularly among young women and among the populations of northern countries such as Canada, which have shorter summers.

However, tanning beds lead to increased health risks, new research suggests.

The risk of developing melanoma, the most deadly form of skin cancer, increases by 75 per cent in those who start using tanning beds before age 35.

The findings mean that officials should ban the use of tanning beds by adolescents under age 18, the researchers said.