The children were assessed after giving blood samples

A University of Siena team studied the level of pain reported by 69 children aged between seven and 12 as they gave blood samples.

Some were distracted by their mothers during the procedure, some had no distraction and some watched cartoons.

Those who watched TV reported least pain, the study - published in Archives of Disease in Childhood - said.

There is evidence to show you can reduce people's perception of pain given the right sort of intervention

Dr Ray MacDonald

The 69 children studied were randomly divided into the three groups to have a blood sample taken.

None of the children was given any form of anaesthesia.

After the samples had been taken, the children and their mothers rated their pain scores.

Children who were given no distraction at all registered pain scores around three times higher than those who watched cartoons.

Even a mother's attempts at distraction, for example by soothing or caressing the child, proved to be no match for the soothing effect of television.

The results suggested that, not only did watching television reduce levels of pain, it also improved children's tolerance of the pain they did register, the team said.

Parental role

The researchers say it is not clear whether the key factor was the distracting power of television or the emotional involvement of mothers undermining their attempts to help their children.

Writing in the journal, they say: "The higher pain level reported by children during mothers' efforts at distraction shows the difficulty mothers have in interacting positively at a difficult moment in their children's life.

"This does not mean that the mothers' presence is negative: although it does not reduce pain, the children will recall that they were not left alone on a stressful occasion.

"Children who are experiencing pain in health care settings of course need the supportive presence of a parent to help them cope effectively.

"Indeed, children state that having their parent present provides the most comfort when in pain."

Researcher Dr Carlo Bellieni said watching television might simply divert attention but it was also possible that the pleasure it generated might stimulate the release of natural painkilling hormones called endorphins.

He said health workers should consider using television to minimise distress for children undergoing minor painful procedures.

He also warned the study underlined the potentially powerful effect of television - which might not be welcome in everyday life.

Dr Ray MacDonald, a psychologist at Glasgow Caledonian University, has carried out research showing that listening to music can counter the pain of undergoing a procedure called haemodialysis in adult kidney disease patients.

He said: "There is evidence to show you can reduce people's perception of pain given the right sort of intervention and I can certainly see parallels between listening to music and watching television."