Exposing children to peanut products earlier in life has resulted in a significant drop in the number of children with peanut allergies in the past decade.Patrick Sison/The Associated Press
There has been an astonishing drop in the number of children with peanut allergies in the past decade.
The principal reason is that babies are eating peanut products earlier in life, and more often, instead of avoiding allergenic foods, as was long recommended.
This should be headline-grabbing news. But in medicine, advances often occur slowly over time, not in one fell swoop, so sea changes can slip under the radar.
New research, published in the medical journal Pediatrics, shows that between 2012 and 2020, the number of children with a peanut allergy declined 43 per cent in the U.S. – falling from 0.79 per cent to 0.45 per cent. Childhood food allergies also fell overall, but at a slightly slower rate of 36 per cent.
The result is that peanuts are no longer the most common allergen in children. Eggs are.
The principal reason allergies are dropping is that guidelines have changed markedly.
In the 1990s, when the number of reported allergies rose sharply, the belief was that it was due to early exposure to allergenic foods. It was recommended back then that babies and infants not consume foods like peanut butter until age three. But rates increased rather than decreased.
We got it wrong, but the scientific process eventually got it right. The approach shifted 180 degrees. Now it is recommended that babies be fed potentially allergenic foods early, often and consistently.
That turnaround came about in a fascinating manner.
Researchers observed that rates of peanut allergy were about 10 times higher in Jewish children in Britain than they were in Jewish children in Israel. In Britain, feeding babies peanut products was a no-no. In Israel, by contrast, babies were often fed Bamba, a popular puffy snack made with peanuts and corn.
A research team conducted a clinical trial where they carefully followed two groups of babies, one that was fed peanut products and another that was not. In the LEAP (Learning About Early Peanut Allergy) trial, half the babies were fed the equivalent of four teaspoons of peanut butter weekly from the ages of four months to 11 months.
At five years old, the children who ate peanut products were 80 per cent less likely to have developed an allergy than the children who were not exposed to peanuts early in life (3.2 per cent vs. 17 per cent). That study led to a dramatic shift in approach, with new peanut allergy prevention guidelines published in 2017 by the National Institutes of Health in the U.S.
But drafting guidelines is the easy part. Getting health professionals and parents to embrace culture change is quite another. Surveys have found that only 29 per cent of American pediatricians and 65 per cent of allergists are following the guidelines.
A 2022 survey in the U.S. found that only 17 per cent of parents had fed their child peanut products by the time their babies were seven months old, rising to 59 per cent by age one. The main reason for the low compliance among parents was the fear they would harm their child.
Allergic reaction happens when the immune system identifies proteins as harmful and releases chemicals that trigger allergic reactions, like hives and respiratory symptoms. But allergists stress that early, regular exposure to potential allergens when a child’s immune system is developing can help the body recognize food proteins as harmless.
In most instances, introducing foods like peanuts can be done safely at home; but high-risk children, like those who have eczema, should undergo testing first. And while early exposure to foods like peanuts reduces risk, it’s not a guarantee that a child will not develop an allergy. We don’t fully understand what causes allergies, other than it is a combination of genetics, environment and exposures.
For example, children born via C-section are far more likely to develop allergies; increasingly sanitized environments have also been singled out as a factor, a theory known as the “hygiene hypothesis.”
As our knowledge of what triggers allergies, and how to prevent them, is changing, so too are the rules.
Increasingly, restrictions on allergenic foods (like peanuts), which had been implemented by many daycares, schools and even airlines, are being dropped. In lieu of bans, we are seeing a harm-reduction approach, with increased awareness and greater availability of epinephrine auto-injectors, like the EpiPen.
While the rate of children with peanut and other food allergies is falling, there are still a significant number of people at risk.
We need to develop new and better treatments, all the while embracing what we have learned about allergy prevention.