YOUNG children who spend more than two hours watching television every day can double their risk of developing asthma, research revealed yesterday.

A study of more than 3,000 children found those who watched a lot of TV around the age of three were more likely to be diagnosed with the condition by the age of 11.

Experts said the link was likely to be down to the lack of physical exercise as
sociated with such sedentary activities as watching TV or playing computer games.

Some 1.1 million children in the UK have asthma, and the number is rising.

The latest study, led by researchers from Glasgow University, used data from the Avon Longitudinal Study of Parents and Children, which has been following the health of 14,000 youngsters and their families.

Parents were questioned annually about any symptoms of wheezing in their children and whether they had been diagnosed with asthma after the age of three-and-a-half. TV viewing habits were also assessed, to compare the hours watched by those children with wheezing symptoms and those without.

The amount of time watching TV was used as a measure of sedentary behaviour because computers and games consoles were not in widespread use when the study started in the mid-1990s.

By the age of 11-and-a-half, some 6 per cent of all those children who did not suffer wheezing at the age of three had asthma. But children who watched TV for more than two hours a day were almost twice as likely to have been diagnosed with the disorder.

The researchers said the relationship between physical activity, sedentary behaviour and asthma was complex. But research suggested breathing patterns in children may be linked to sedentary behaviour, sparking developmental changes in the lungs and wheezing.

Dr Elaine Vickers, research relations manager at Asthma UK, said: "This study does not suggest watching TV directly causes asthma but uses the amount of time children spend in front of the television as an indication of how much time they spend sitting down rather than running around.

"The findings add to a wealth of evidence linking a lack of exercise and being overweight with an increased risk of asthma, but this study is the first to directly link sedentary behaviour at a very young age to a higher risk of asthma later in childhood.

"We have one of the highest rates of childhood asthma in the world, so it is especially important parents try to prise their kids away from the TV and encourage them to lead an active lifestyle. This includes children with asthma, who can also greatly benefit from regular exercise."