For years, parents of kids at high risk of developing peanut allergies were told to avoid nuts to minimize their risk. But that approach hasn't been working and the rate of peanut and other food allergies continues to climb in Canada and elsewhere.
In recent years, there's been concern that delaying the introduction of peanuts to babies isn't preventing allergies; it might actually be promoting them.
Now, a new, long-term study provides the first evidence that peanut allergies can actually be prevented if kids are given peanuts early in their first year, and then continually exposed to them through their preschool years.
The findings could be game-changing for parents with kids at risk of peanut allergies, since there is no cure for the allergy, which is often severe and which kids rarely outgrow.
In this new study, dubbed LEAP (Learning Early About Peanut Allergy), researchers from the U.K. studied 640 babies over the age of four months who had either severe eczema, an egg allergy, or both – all signs that they were at risk of a peanut allergy.
The kids were then given a small amount of peanut protein to see how they reacted. The parents of the kids who showed no reaction were then randomly broken into two groups.
The first group was told to keep their kids diets peanut-free, while the others were told to feed their children a few grams of peanut protein broken up into three or more meals a week. All the parents filled out food frequency questionnaires to ensure the diets were being followed.
The study found that the children who were regularly exposed to peanuts had a much lower risk of developing an allergy by the time they were five years old.
When considering all the children in the study -- including those kids who were unable to tolerate peanuts early on -- only 3.2 per cent of the kids who regularly ate peanuts developed a full allergy, compared with 17.2 per cent in the group who avoided peanuts.
That's an 80 per cent reduction in the prevalence of peanut allergy. The full results appear in the New England Journal of Medicine.
But before parents "even start any kind of introduction" children should be skin-tested to prevent life-threatening reactions, cautions Dr. Rebecca Gruchalla, an allergy specialist at the University of Texas Southwestern Medical Centre.
Gruchalla, who wrote a commentary on the study, also notes small children can choke on whole peanuts, so smooth peanut butter or other peanut-based foods are a safer option.
All of the babies in the study were tested to make sure they didn't already have a peanut allergy; parents of babies thought to be at risk should not try this on their own.
About one in 50 children in Canada have a peanut allergy. According to recent studies, the incidence of peanut and tree nut allergies among kids has tripled in the last 20 years.
In 2000, the American Academy of Pediatrics recommended delaying introducing peanuts to kids at high risk of allergy until they were three years of age. But peanut allergy rates only increased, so in 2008, that advice was rescinded.
The Canadian Pediatric Society now recommends not delaying introducing any solid food beyond six months of age.
Peanut allergies have long been difficult to explain and so, for years, Dr. Douglas Mack, a pediatric allergist in Burlington, Ont., says doctors used the best evidence they had to come up with their guidelines. But he says it's now becoming clear the old rules about avoiding certain foods to prevent allergies need to be scrapped.
"We are humble enough to revise them as current evidence comes out and I think that is exactly what is going to be happening here," he told CTV News.
It's not clear why regularly offering peanuts to young kids might prevent allergies, but Mack says there appears to be a "window of opportunity" when even kids at high risk can develop a tolerance to peanuts.
Mack says while this was a large study, it's not clear whether the findings apply to all children and to all potentially allergenic foods, such as seafood, milk and eggs.
In an accompanying editorial, a pair of U.S. immunologists notes there are still many questions that need to be answered, including how much peanut protein is needed to be effective, and how long kids need to eat peanuts before they are no longer at risk of developing an allergy.
But they say that the findings of this study are so compelling, it is clear that new recommendations will be coming soon.
With files from The Associated Press
