"This study could help to develop skin creams and other products to protect skin from sun damage, as well as increasing our understanding of the mechanism by which they act", she said.

Researchers now believe that full sunscreen blockage is not necessarily good in sun creams because they block certain wavelengths of light needed to trigger the body's natural defences.

Oestrogen-like substances, including chemicals known as parabens, occur in cosmetics, sun creams and moisturising lotions.