. . " suggests that cutting calories by 40 per cent could add an extra 20 years to a person's lifespan.The study is unique in that it treats all age-related diseases, including Alzheimer's and cardiovascular disease, as having a common cause - the disease of ageing itself.Gallery: 10 health myths bustedDr Piper told newspapers that if we discover the genes involved with ageing, we should be able to de" . . .