SCIENTISTS believe they may have discovered the secret of eternal youth - by studying sufferers from premature ageing.

Patients with a disorder known as Werner Syndrome suffer skin wrinkling, baldness and greying hair in their teens.

They are also highly prone to cancer, and most die in their 40s or 50s.

A team of scientists was led by Dr Jan Karlseder from the Salk Institute in La Jolla, California.

The findings suggest that lengthening telomeres - `caps' of DNA on the end of chromosomes - can hold back ageing - and possibly prevent cancer.

Dr Karlseder said: "I predict that cancer in older people has the same basis as that seen in Werner Syndrome patients."