Eating peanuts helps prevent babies becoming allergic later, study suggests
New research suggests that feeding peanuts to high-risk infants before the age of one can prevent the common food allergy later in life
For years, parents of babies who seem likely to develop a peanut allergy have gone to extremes to keep them away from peanut-based foods. Now a major study suggests that is exactly the wrong thing to do.
Exposing infants like these to peanuts before age one actually helped prevent a peanut allergy, lowering that risk by as much as 81 per cent, doctors found. Instead of provoking an allergy, early exposure seemed to help build tolerance.
Dr Anthony Fauci, director of the National Institute of Allergy and Infectious Diseases, called the results "without precedent" and said in a statement that they "have the potential to transform how we approach food-allergy prevention".
His agency helped fund the study, the largest and most rigorous test of this concept. Results were published online on Monday in the New England Journal of Medicine and discussed at an American Academy of Allergy, Asthma and Immunology conference in Houston.
A big warning, though: The babies in the study were checked to make sure they did not already have a peanut allergy before they were fed foods that included peanuts, so parents of babies thought to be at risk for an allergy should not try this on their own.
"Before you even start any kind of introduction, these children need to be skin-tested" to prevent life-threatening reactions, said Dr Rebecca Gruchalla, an allergy specialist at the University of Texas Southwestern Medical Centre in Dallas.
Small children could choke on whole peanuts, so smooth peanut butter or other peanut-based foods were safer, said Gruchalla, who wrote a commentary on the study in the journal.
The main finding - that early exposure to a problem food may keep it from becoming a long-term problem - should change food guidelines quickly, Gruchalla predicted.
Peanut allergies have doubled over the last decade and now affect more than 2 per cent of children in the United States and growing numbers of them in Africa, Asia and elsewhere. Peanuts are the leading cause of food-allergy-related severe reactions and deaths.
Researchers at King's College London started this study after noticing far higher rates of peanut allergies among Jewish children in London who were not given peanut-based foods in infancy compared to others in Israel who were.
The study involved more than 600 children from four months to 11 months old in England. All were thought to be at risk for peanut allergies because they were allergic to eggs or had eczema, a skin condition that's a frequent allergy symptom.
All had been given skin-prick tests to make sure they were not already allergic to peanuts. They were put into two groups - 530 who did not show signs of peanut allergy and 98 others with mild-to-moderate reactions, suggesting an allergy was developing.
Half of each group was assigned to avoid peanuts and the other half was told to consume them each week, usually as peanut butter or a snack called Bamba, a peanut-flavoured puff.
At age five, among children with no sign of allergy on the skin test, only two per cent of peanut eaters developed the allergy, versus 14 per cent of abstainers.
The results were mirrored among children with some reaction to peanuts on the skin test: Only 11 per cent of peanut eaters developed an allergy versus 35 per cent of abstainers.
Gruchalla thinks that babies with some signs of a peanut-allergy risk, such as parents who are allergic, should have a skin test between four and eight months of age. If it is negative, they should be started on peanut products as the babies in the study were.