A trio of studies published over the past year all point to the same conclusion: that early introduction of peanuts to an infant's diet has a significant and lasting reduction in the potential development of an allergic response later on.
According to the American College of Allergy, Asthma & Immunology, symptoms of a peanut allergy can include itching and tingling of the mouth and throat, nausea, a congested or runny nose, itchy skin or hives, and in extreme cases, anaphylactic shock. The American Academy of Pediatrics (AAP), states that in westernized countries, peanut allergies have been consistently on the rise over the past 10-15 years, with 1-3% of children testing positive for an allergic reaction. In the United States alone, the numbers have tripled, with 100,000 new cases annually-that's 1 in 50 children exhibiting symptoms of a peanut allergy. It seems to be at epidemic proportions, precipitating rules that ban peanuts from schools, daycare centers, and other public spaces. It makes sense to want to avoid something that may cause a child harm. But what if all the fear and avoidance of peanuts is the very mechanism behind the rapid rise in this type of allergy?
The First Study
Results from a study published last year in The New England Journal of Medicine suggest that the practice of having children avoid potential allergens until at least the toddler years does not have to be the norm anymore. Dr. Gideon Lack, a pediatric allergy professor at King's College London, conducted a study called LEAP (Learning Early About Peanut Allergy). Dr. Lack studied over 600 babies aged 4-11 months who were at high-risk for developing a peanut allergy since they already exhibited eczema or egg allergies. The AAP's summary of this study stated that the babies were followed to age 5, and it was discovered that if fed the equivalent of 4 heaping teaspoons of peanut butter a week, their absolute risk of developing a peanut allergy by age 5 was reduced by 14% and their relative risk dropped by 80%. This study was groundbreaking in that if offered a potential solution to the onslaught of peanut allergies worldwide. However, since it ended when the children were 5 years old, there remained the question of how the effects of early introduction would last.
The Second Study
The LEAP-On Study was a follow-up study to LEAP with the same group of researchers. This study asked the question, if babies were introduced to peanuts within the first year of life and ate them consistently until 5 years old, after which they completely avoided all peanut products for a year, would the tolerance remain in their systems, or would they develop an allergy. The researchers followed 556 children from the original group until they turned 5. The children then avoided all peanut products for a full year, and when they were 6 years old, peanuts were reintroduced to their diets. Although a few children developed an allergic response, no major increase in allergies was found. Therefore, the study seemed to correlate with prior results, showing that early introduction of peanuts reduces the onset of allergies. As this study concluded, a third question remained. Researchers wondered if early introduction of other allergenic foods would have the same results.
The Third Study
With the most recent study dubbed EAT (Enquiring About Tolerance), the researchers wanted to see how early introduction of foods would affect the general infant population, and not just high-risk babies. They also wanted to try introducing more than just peanuts, so they included a larger variety of allergenic foods including eggs, milk, wheat, fish, and sesame.
Another question was if a difference in allergy rates could be detected by introducing these foods at various points within the first year. The EAT study looked at 1,303 babies who were 3 months old when the study began. One group did not introduce the foods until the babies were 6 months old. Another group introduced the foods at 3 months of age. The children were tracked for three years to see if any of them developed allergies between 1-3 years of age. The results of the study showed that the group who ate the foods earliest-at 3 months, had a 67% overall lower risk of developing an allergy to these foods than the children who waited until 6 months of age to try them. The positive effects of early introduction seemed to be greater with respect to peanuts and eggs as opposed to the other foods on the list. The researchers also noted that introducing the foods at random did not make a difference. The effects were best when the foods were consumed consistently and in the correct amounts.
Following the original LEAP study, in 2015 the AAP put out interim guidelines based on the new evidence. They recommended that infants could be given peanut products between 4-11 months of age in order to reduce the risk of developing a peanut allergy when older. In order for this to be effective, consistent weekly introduction is key. Peanuts can be introduced as peanut butter mixed with milk or pureed fruit, ground peanuts mixed with yogurt, or peanut soup. Whole peanuts are never recommended, as they constitute a choking risk. It is also recommended that before engaging this protocol, it is important to consult with the baby's pediatrician. In particular, if a baby is suspected to be at risk for an allergy, the first introduction to the food is recommended to be done at the doctor's office, where treatment can be provided if a serious and adverse reaction were to occur.
In March and April of 2016, The National Institute of Allergy and Infectious Diseases (NIAID), reported that it is currently working on an update to their 2010 guidelines on this subject, and will be releasing a newly revised set of guidelines in the near future based on the results of the LEAP study.
Although results vary based on how closely the introduction protocol is followed, the evidence does point strongly toward the idea that introducing peanuts early on in a child's first year can go a long way toward reducing the chances of that child developing an allergy later on. Early and consistent introduction seems to set the child's system up to be less sensitive to peanuts. Even if peanuts are avoided later, the fact that they were eaten within the child's first year has a lasting effect on reducing allergies. The LEAP study points to a new way of protecting children from peanut allergies-by controlled exposure rather than complete avoidance. As this approach becomes more commonplace, it will be interesting to see if the numbers of peanut allergies worldwide begin to decline.