Early introduction of peanut, egg to infants associated with intake of other allergens
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Key takeaways:
- Caregivers introduced 17.2% of infants to peanut and 15.5% of infants to egg by age 7 months.
- Caregivers who introduced infants to peanut by age 7 months also introduced a mean of 5.4 other food allergens.
More than half of caregivers did not introduce peanut and one-third did not introduce egg to their children before age 1 year, despite guidelines to do so, according to a study published in Pediatric Allergy and Immunology.
These introductions also are associated with increased intake of other food allergens, the researchers wrote.
“Parents who are willing to introduce peanut and egg in infancy are much more likely to introduce other food allergens than parents who are reluctant to introduce food allergens,” Carina Venter, PhD, MD, associate professor of pediatrics, section of allergy/immunology, Children’s Hospital Colorado, told Healio.
Study design, results
When the researchers began the study, they were in the planning phase of a very large randomized controlled trial to understand whether it was possible to prevent food allergy in infants by encouraging early incorporation of commonly allergenic solids into their diet around age 4 months.
“However, we realized very little was known at the time regarding current feeding behaviors among US infants, particularly since the publication of a set of infant feeding guidelines in 2017, which advocate early introduction of peanut for primary prevention of food allergy,” Christopher M. Warren, PhD, director of population research at the Center for Food Allergy & Asthma Research, Northwestern University Feinberg School of Medicine, told Healio.
The researchers surveyed 3,062 caregivers of children aged 7 months to 3.5 years in the United States between Jan. 21 and Feb. 15, 2021. Eight percent of biological mothers and 5% of biological fathers reported a history of food allergy.
Among biological mothers, 9% had eczema, 10% had asthma and 17% had environmental allergies. Among biological fathers, 6% had eczema, 9% had asthma and 19% had environmental allergies.
Caregivers introduced peanut to 17.2% of their children by age 7 months and 58.8% of their children by age 1 year. Also, they introduced egg to 15.5% of their children by age 7 months and 66.4% by age 1 year.
Further, caregivers introduced one of the top nine food allergens to 48.1% of their children and all nine of the allergens to 0.4% by age 7 months. Specific introductions by age 7 months included 26% for wheat, 18.7% for cow’s milk, 4.3% for soy, 4.4% for at least one tree nut, 3.7% for sesame, 3.1% for finned fish and 2.1% for shellfish.
By age 13 months, 94.1% of children had been introduced to at least one of these foods and 2.5% had been introduced to all nine. At age 1 year, 62% had foods that included cow’s milk, 74% had wheat, 21.1% had soy, 28.1% had finned fish, 26.9% had sesame, 26.3% had one or more tree nuts and 15.8% had shellfish.
Among caregivers who introduced their children to peanut by age 7 months, additional introductions included wheat (50.1%), egg (42%), milk (32.3%), tree nuts (13.2%), finned fish (10.5%), shellfish (7.1%), sesame seed (11%) and soy (7.2%).
Other introductions among caregivers who introduced their children to peanut by age 1 year included wheat (81.9%), egg (76.5%), milk (69.5%), tree nuts (36.3%), finned fish (36.4%), shellfish (21.5%), sesame seed (33.4%) and soy (26%).
Caregivers who introduced their children to peanut by age 7 months also introduced their children to a mean of 4.51 additional top nine allergens by age 1 year, whereas those who introduced their children to peanut after age 6 months introduced their children to a mean of 2.93 additional top nine allergens by age 1 year (t = –11.35; P = < .001).
Additional introductions among children who had egg before age 7 months included wheat (53.2%), peanut (46.4%), milk (37.9%), sesame seed (14%), tree nuts (13.2%), finned fish (12.2%), shellfish (8.2%) and soy (9.8%).
Similarly, additional introductions among children who had egg before age 1 year included wheat (84.2%), milk (68.5%), peanut (67.8%), finned fish (35.5%), sesame seed (33.3%), tree nuts (31.4%), soy (24.6%) and shellfish (19.7%).
There was a mean of 4.49 additional food allergens introduced before age 1 year among children who had egg by age 7 months and a mean of 2.88 additional food allergens among those children who had not had egg by age 7 months (t = –10.49; P = < .001).
Using two negative binomial regression models, the researchers said, there was an association between earlier introduction of peanut and egg and the introduction of a comparable number of other common allergenic solids before age 1 year.
During infancy, the researchers continued, peanut butter and scrambled egg were the most common types of peanut and egg consumed. Before age 7 months, 21% of infants had thinned peanut butter, which fell to 19% by age 1 year and then 10.8% afterward. Types of egg did not vary based on age.
Although commercial products designed to introduce infants to these allergens are available, the researchers said, only 3.1% of caregivers used one of them at least once, and 0.9% reported using one of them three or more times.
There were no associations between annual household income, respondent educational attainment, race or ethnicity, parental age, child eczema status, or the presence of a food-allergic sibling with use of these products (P < .05).
However, the researchers said, caregivers aged younger than 30 years were significantly less likely to use these products than caregivers aged older than 44 years (OR = 0.32; 95% CI, 0.11-0.9). Also, children with a biological parent with food allergy were more likely to use one of these products three times or more (OR = 2.2; 95% CI, 1-4.73) but not use one of these products at least once (OR = 1.3; 95% CI, 0.84-2.15).
Finally, children who had seen an allergist for a food allergy were significantly more likely to use one of these products at least once (OR = 5.4; 95% CI, 3.5-8.4) or three or more times (OR = 6.7; 95% CI, 3-15.2).
Conclusions, next steps
Although the 2017 Addendum Guidelines for the Prevention of Peanut Allergy in the United States from the NIAID-Sponsored Expert Panel recommend introduction of peanuts during infancy based on risk level, the researchers said, fewer than one in five caregivers in this study introduced peanuts to their infants by age 7 months. Yet these figures represent a substantial increase from 2016 data, the researchers continued.
These findings indicate that caregivers are unamenable to, unaware of or unconvinced of the benefits of early introduction, the researchers said, and that these caregivers would benefit from practical advice about introduction. The researchers expected similar improvements with educational materials regarding egg introduction as well.
As these introductions appear associated with the introductions of other allergens based on the findings of this study, the researchers said, improving rates of peanut and egg introduction would improve introductions of those other allergens as well.
“We can perhaps just focus on informing parents to introduce peanut and egg into the infant’s diet and the rest will follow naturally, rather than giving a complex message of introducing all allergens during one nutrition consultation,” Venter said.
These conversations do not have to be difficult to initiate, the researchers said.
“We know that if your pediatrician discusses early introduction, caregivers are more likely to do it. The 4- and 6-month well-child visits are very busy, and there is not much time for this conversation,” Ruchi Gupta, MD, MPH, professor of pediatrics and medicine at Northwestern Feinberg School of Medicine, told Healio.
“Incorporating some prompts in your visit notes is helpful, as well as written information you can give to families. We have developed these as part of an NIH grant and would love to share,” said Gupta, who also is a Healio Allergy/Asthma Peer Perspective Board Member.
Meanwhile, the researchers are now conducting their randomized controlled trial of food allergy prevention.
“We will continue to recruit and follow up with a large, diverse sample of infants to learn more about the preventive effects of early allergen introduction as well as to carefully document typical infant feeding practices in the control arm,” Warren said.
“We are planning for the results of this study to inform national infant feeding guidelines that help parents and physicians determine the healthiest way to feed young babies in a way that also prevents food allergy, especially among infants at high risk of allergy,” he said.
For more information:
Carina Venter, PhD, MD, can be reached at carina.venter@childrenscolorado.org. Christopher M. Warren, PhD, can be reached at christopher.warren@northwestern.edu. Ruchi Gupta, MD, MPH, can be reached at r-gupta@northwestern.edu.