Keeping a cat in the home may prevent asthma in young children, according to Danish scientists.
A study of nearly 400 toddlers revealed that those growing up with a cat had a far lower likelihood of suffering from the inflammatory condition.
Researchers believe this is due to a genetic variation that plays a significant role in triggering asthma which is somehow switched off in the presence of a cat.
It’s very exciting that they find this connection because other studies have struggled to conclude anything final
Dr Arne Høst
However, the same gene does not appear to be affected by the presence of dogs.
When activated, the variation of the TT gene doubles the risk of asthma and is also responsible for bronchitis and pneumonia.
Almost one in three children in the study carry the variant, which experts believe is proportionate to the population in general.
Jakob Stokholm, who led the study at the Copenhagen Studies on Asthma in Childhood Research Center, said: the explanation could be related to bacteria that cats carry and perhaps fungi or viruses that they bring into the home.
“If we can explain these mechanisms, it opens up opportunities to isolate them and to protect against the disease,” he said.
The TT gene variant was previously suspected to be involved in some way to asthma, bronchitis and pneumonia, however scientists did not know precisely how.
"It’s very exciting that they find this connection because other studies have struggled to conclude anything final,” said Dr Arne Høst, who co-led the research.
“Now it looks like the effect is linked to a particular gene-variant, which goes to show just how complex the development of asthma and allergies are," he added.
"It’s not only about genes and the environment, but how the two interact, and there’s so much that we still don’t know.
Approximately 5.4 million people in the UK are currently receiving treatment for asthma, including more than 1.1 million - equivalent to one in 11 - children.
Professor Hans Bisgaard said the study showed in unprecedented detail how the environment affects the behaviour of genes, in particular in early life and during pregnancy.
“For me, this is the core message because it’s a recognition in the direction of how disease occurs,” he said.