Peanut products such as puffed snacks and peanut butter should be given to children from four to six months of age to reduce the risk of them developing a peanut allergy, experts have said.

Studies suggest the prevalence of peanut allergy among children in western countries has doubled in a decade. About one in 50 children in the UK have the condition, with about 13,000 infants developing a peanut allergy each year. The condition can be life-threatening and create a constant worry for parents and children who have to avoid exposure.

Now researchers say prevalence in the UK could fall by 77% if all babies were introduced to peanut products between four and six months of age.“You’d stop 10,000 infants each year developing peanut allergy – [a] huge number and a real opportunity for preventive medicine,” said Graham Roberts, a professor in paediatric allergy and respiratory medicine at the University of Southampton and a co-author of the analysis.

Gideon Lack, a professor of paediatric allergy at King’s College London, and another author, said that while for many years countries including the UK had been advocating that parents should avoid giving peanut products to young babies, and then introducing them very gradually, the data now showed the importance of early introduction.

In fact, the former advice could have contributed to the explosion in peanut allergy alongside other factors such as an increase in eczema in children and greater exposure to peanuts in their environment through increased consumption by others, the researchers say.

“We believe peanut allergy develops by exposure to peanut products in the home through the skin,” said Lack, noting that children with eczema were at increased risk of peanut allergy, and that the risk was higher the more severe their eczema is.

However, the team said early introduction of peanut products should not be confined to children with the skin condition, as peanut allergy could also develop in children with no eczema.

The research, published in the Journal of Allergy and Clinical Immunology, is based on analysis of two large studies, the Learning Early About Peanut Allergy (Leap) trial, and the Enquiring About Tolerance (Eat) trial. While both have previously shown the benefits of early introduction of peanut products to infants, questions remained including the optimal age for introducing such foods.

The team say their analysis shows peanut allergy mostly develops at between six and 12 months of age.

What is more, the impact of early introduction in preventing peanut allergy decreases as the age of first introduction rises – an effect particularly pronounced in infants with severe eczema and in minority ethnic children.

The researchers say children with eczema should be introduced to peanut products from four months old, and that if other infants were given peanut products from six months of age – a delay acknowledging the challenges of introducing foods – there could be a 77% reduction overall in peanut allergy in children.

Mary Feeney, a clinical research dietitian at King’s College London and another author, said government advice that says peanut products can be introduced to infants from about six months should be reviewed in light of the recent studies.

She said breastfeeding should continue alongside introduction of solid foods, but that parents should aim to give infants the equivalent of a heaped teaspoon of peanut butter three times a week. Foods such as peanut puffs could be crushed into a porridge for a smooth texture for babies but whole or chopped nuts should not be given due to the risk of choking.

Lack saiid that in Israel, where peanut butter puffs are a popular infant snack, the prevalence of peanut allergy in children was about a 10th of that seen in the UK.

But he said there were barriers to achieving early introduction of peanut products in the UK. “Part of it is culture, part of it is fear, part of it is this dichotomous belief that a child is either exclusively breastfed or eats solids, whereas the two can coexist,” he said.