Peanut allergy affects up to 1 in 50 children in the UK. However evidence increasingly suggests that eating peanut products from an early age can reduce the risk of allergy.

New analysis by researchers from Southampton and London has identified a ‘window of opportunity’ to introduce smooth peanut products. If all babies were introduced to peanuts this early in life, they say overall allergy rates could plummet by more than three quarters.

Why would this reduce the risk of allergy? And can parents apply these principles to other foods?

We spoke to lead author Professor Graham Roberts from the NIHR Southampton Biomedical Research Centre to find out more.

What is peanut allergy?

Peanut allergy occurs when the body mistakes peanut as something dangerous and reacts to it. The reaction can involve the whole body - your lips may swell up, you may get an itchy rash and you may start having problems with your breathing.

When does this research suggest babies should first be introduced to peanut products?

Our research suggests that all babies should be introduced to peanut between four and six months of age. Some babies are at higher risk of developing a peanut allergy, such as those with severe eczema or an egg allergy. They should be introduced to peanut at four months of age if they are developmentally ready for solids.

Do you know why introducing peanut products at an early age reduces the risk of allergy?

A baby’s immune system needs to learn how to differentiate between food and dangerous bugs that need to be kept out of the body.

The way the body does this is through the form it sees things in. If it sees peanut in reasonably large amounts in the gut, it will come to see this as a safe food and will not develop an allergy to peanut.

How would you recommend parents introduce peanut products to their children?

Parents are recommended to start offering their babies small amounts of vegetables, fruit and starchy foods (e.g. baby rice) as a puree initially. Once they are eating some of these, peanut products (e.g. peanut butter) can be introduced.

Are there potential risks of introducing peanut products in early life?

The first risk of giving peanuts to pre-school children is choking. To avoid this, parents should use peanut products like smooth peanut butter or Bamba. Pre-school children should not be given whole or chopped nuts.

Parents may also worry about the risk of allergic reaction. However, our research clearly shows that babies introduced to peanut between four and six months of life are much less likely to have a reaction to peanut than babies introduced after six months of age.

What should parents do if their child has an adverse reaction to their first taste of peanut?

In our experience, babies usually only have minor reactions to peanut. This might be some swelling or an itchy rash. These tend to get better quickly; some antihistamine may make the child more comfortable. A more serious reactions would involve breathing problems but this is extremely rare in babies. If there are breathing problems with an allergic reaction, a 999 ambulance should be immediately called.

What were the clinical trials that you have used in this analysis?

The analysis used two big, randomised control trials:

Learning Early About Peanut Allergy (LEAP)

The landmark study involved 640 children from the United Kingdom between 4 and 11 months of age who were identified as high risk for peanut allergy. It found that early introduction to peanut in high-risk babies protected against the development of peanut allergy.

Enquiring About Tolerance (EAT)

This study involved 1,303 exclusively breast-fed children from England and Wales. It found that introducing babies to six foods (milk, peanut, sesame, fish, egg, wheat) between four and six months of age could reduce the risk of allergies developing.

Can the results of this study be trusted?

This study is an analysis of data that’s already been collected.

We looked at results from two UK studies that were both very well carried out. They cover the entire population, including infants that are both high risk and low risk of peanut allergy. They also cover the entire population in terms of ethnicity, so we think they can be trusted.

We have been very careful with our assumptions and believe that they are conservative.

How do these findings compare to current guidance given to parents about peanut allergy?

Current guidance suggests that peanut should be introduced from around six months of age. The last government report on introducing food into babies’ diets was published in 2018. Since then, a number of studies have been published that suggest earlier introduction of peanuts and other foods can help prevent allergies from developing. These studies also show that introducing foods early does not conflict with mothers continuing to breast feed their infants until 6 months or more.

Do these findings mean that current guidance on the introduction of peanut will be changed?

We think that the government should review the current guidance on when to introduce peanuts into babies’ diet. In our view, peanuts should be introduced earlier if infants are developmental ready for solids.

Can parents apply these principles to other foods?

Data from trials in other countries suggests that early introduction of other solids can reduce the risk of food allergy to these foods. However, we need more data about the best way for parents to introduce other foods into infants’ diet in the UK before we would suggest changing the recommendations for other foods in the UK.

Preventing peanut allergy: Q&A with Prof Graham Roberts