A LIFE of po-faced self-denial and thinking that animals are people can reduce the risk of cancer, doctors have claimed.

Research shows a point blank refusal to give in to your base instincts can add anything up to four years to your self-satisfied existence.

The latest study comes as the British Medical Association grouped tumours of the bowel, liver and lung into a new category known as the ‘fun cancers’.

A BMA spokesman said: “Anything more thrilling than Songs of Praise will sprout tumours like mould on a week-old loaf.”

Research also showed that exciting sex, fast cars and watching films with explosions can also curtail life expectancy.

But Professor Henry Brubaker, of the Institute for Studies, said: “The most common carcinogen is one that is known in the scientific community as ‘being alive’.

“I do not understand how some people can go through life without doing shots off someone’s naked bum while having a sneaky fag.

“It’s just so odd.”