Parents among you are surely familiar with the guilt that arises from being too tired to bake your little ones fresh, nutritious zucchini frittata, and once again pulling open a bag of an ultra-processed snack. Hey slackers, give yourselves a pat on the back: If the snack contains peanut butter, you may have spared your little ones from becoming allergic to peanuts. A long-term prospective study demonstrates that exposure to peanut-containing snacks, such as Bamba, in infancy leads to resistance to peanut allergy, which is maintained at least until 12 years of age.
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Peanut allergy comes from an inappropriate immune response to a protein found in peanuts and can trigger symptoms ranging from a runny nose to anaphylactic shock, which can be fatal if not treated promptly. Its prevalence in the Western world is high (1–2 %) and even rising. What makes coping with the allergy so complicated is the fact that peanuts, or trace amounts from production lines, are very common in many foods, making exposure hard to avoid. Each year, 7–14 % of allergic individuals are accidentally exposed to peanuts, and about a third of them will experience anaphylactic shock. Another unfortunate fact is that, unlike many other childhood food allergies, peanut allergy can persist into adulthood [1, 2].
In 2008, a British-Israeli study discovered an interesting phenomenon: peanut allergy is significantly less common among Israeli children than among Jewish children in Britain who share a similar genetic background [3].
Anyone who has raised small children knows that toddlers under the age of five are usually advised not to eat whole peanuts and other nuts since they are a choking hazard, so their exposure to these foods generally begins later. In Israel, however, babies who reach four months of age and start trying solid foods can happily nibble on a soft, melt-in-your-mouth snack that contains peanut butter. We are, of course, talking about the undisputed delicacy—Bamba—a corn-puff snack coated in a thin layer of peanut butter.
The finding that allergy prevalence is much lower in Israel led a group of researchers to investigate whether exposure to peanuts from infancy could prevent the development of life-threatening allergy later in life. In May 2024, the most up-to-date follow-up results of this study, which has been running for over 15 years, were published.
About 640 infants aged four to eleven months who showed a tendency to develop allergies such as eczema and egg allergy—and were therefore at higher risk of developing peanut allergy [4]—were selected for the study. In the first phase, the researchers determined which infants were already sensitive to peanuts by performing a skin-prick test. Anyone who has tried to identify which flower is responsible for their springtime seasonal allergies is likely familiar with this test: the skin is pricked, various allergens are introduced, and the swelling around each puncture is measured to determine sensitivity.
From that point on, the study proceeded with two distinct groups—those whose skin swelled, indicating existing sensitivity to peanuts, and those whose skin did not react. Each group was then divided in two: toddlers who regularly ate Bamba until the age of five, and those who did not.
Several years after the study began, when the children reached the age of five, all were tested for peanut allergy using an oral food challenge [5], in which the children consume a measured dose of peanut protein under supervision and their symptoms are recorded. In addition, blood tests were performed to measure antibodies to peanut protein and antibodies that suppress the immune response to peanuts. In the blood of peanut-allergic individuals, there is a high level of antibodies to peanut protein relative to the suppressive antibodies.
The researchers found that the proportion of allergic children was far lower in the groups exposed to Bamba during their early years compared with those who avoided peanuts. Moreover, several children who showed a reaction in the initial skin-prick test no longer had any peanut allergy at age five thanks to their early exposure to Bamba [6]!
In the later stages of the study, the researchers followed up with the children—now 12 years old, more than 11 years after joining the study—to see who was allergic to peanuts. This was done to assess how well the tolerance induced by early peanut consumption persisted into early adolescence. The prevalence of allergy among children who routinely ate Bamba until age five was significantly lower than among those who avoided it. As with the five-year test, this difference also appeared in the group that had shown a skin reaction in infancy: in some of them, the allergy had disappeared completely by age 12 [7].
To verify that exposure until age five is sufficient to cement tolerance regardless of later exposure levels, some children were instructed to avoid peanuts entirely between ages five and six. Early exposure still protected these children from developing allergy [8].
Across all experimental groups combined, the researchers estimate that early peanut exposure reduces the likelihood of developing allergy by about 75 %. Because the protective effect of early exposure has been shown to last for several years, the researchers assume that the tolerance will be sustained for life. To confirm this, they will need to revisit the participants later to see whether anyone develops an allergy.
So, you can stop beating yourself up over all the times you were too lazy and handed your child yet another bag of Bamba. In the meantime, join us in patiently awaiting the next prospective study—hopefully one that will extol the superior virtues of Cheetos.
*The above does not constitute medical advice; in any case of suspected allergy, consult your physician.*
Hebrew editing: Smadar Raban
English editing: Elee Shimshoni
Sources and further reading
[1] Review article on the global prevalence of peanut allergy
[2] Review article on peanut allergy in the journal of the American Academy of Pediatrics
[4] Article describing the study population—children with a tendency toward allergies
[5] Oral food challenge test—Cleveland Clinic
[6] Article detailing the study results when participants reached age five
[7] The new article detailing the study results when participants reached age 12
Sagie serves as Scientific Director at “Little, Big Science.” He holds a PhD from the Department of Molecular Genetics at the Weizmann Institute and works as a computational biologist at a company developing personalized cancer treatments.
Elee serves as Scientific Director at “Little, Big Science.” She holds a PhD in Biology from the Weizmann Institute and completed her postdoctoral training at Harvard and MIT. Her expertise lies in cancer, inflammation and metabolism, as well as in developing complex human-cell based model systems of disease.
