Lead researcher Dr Simone Ribero, from King's College London, said: "For many years dermatologists have identified that the skin of acne sufferers appears to age more slowly than in those who have not experienced any acne in their lifetime.

"Whilst this has been observed in clinical settings, the cause of this was previously unclear.

"Our findings suggest that the cause could be linked to the length of telomeres which appears to be different in acne sufferers and means their cells may be protected against ageing.

"By looking at skin biopsies, we were able to begin to understand the gene expressions related to this. Further work is required to consider if certain gene pathways may provide a base for useful interventions."

The study, published in the Journal of Investigative Dermatology, looked at 1,205 female twins, a quarter of whom reported having had acne.

One of the genes involved in telomere length was also found to be associated with acne, suggesting that being spotty did not slow ageing itself but flagged up what was happening in a person's cells.

Analysis of skin samples from the twins highlighted a gene pathway called p53, which regulates apoptosis, or "programmed cell death" - a kind of cell suicide.