Fathers who smoke pass on damaged DNA to their children raising the risk of cancer, research shows.

A study found that smoking harms the father's DNA, and these damaged genes can be inherited by his children.

This raises the risk of youngsters developing childhood cancers, particularly leukaemia, warn researchers at the University of Bradford.
Because a fertile sperm cell takes three months to fully develop, fathers should kick the habit 12 weeks before conceiving to avoid the risk, Dr Diana Anderson said.
She added: 'Smoking by fathers at the time around conception can lead to genetic changes in their children. These changes may raise the risk of developing cancer.'
Meanwhile scientists at the University of Glasgow have also found that men who drink lots of tea are far more likely to develop prostate cancer.

They found that those who drank seven or more cups a day had a 50 per cent higher risk of contracting the disease than men who had three or fewer.

The warning comes after researchers tracked the health of more than 6,000 men for four decades.

Their findings run counter to previous research, which had suggested that tea-drinking lowers the risk of cancer, as well as heart disease, diabetes and Parkinson's disease.