Canada's CHILD Cohort Study and Food Allergy Prevention
Learn what new findings based on data from the CHILD Study illuminate about early allergen introduction and food allergy prevention, and which combined conditions drastically increase a child's risk of developing a food allergy.
The Canadian Healthy Infant Longitudinal Development Study, commonly known as the CHILD Cohort Study, examines the development of food allergies and other conditions in a cohort of thousands of Canadian children.
New findings based on data from the CHILD Study further emphasize the importance of early peanut introduction for reducing a baby's risk of developing peanut allergy.
According to results published in the Journal of Allergy and Clinical Immunology (JACI), even infants at low risk of peanut allergy should eat peanut in their first year of life, to reduce their food allergy risk.
Other findings from CHILD data highlight which combined conditions place children at greater risk for developing a food allergy.
Eczema, Sensitization, and Food Allergy Development: Findings from CHILD Data
A JACI study using CHILD cohort data, conducted by Maxwell M. Tran, BHSc, and others, examined the "atopic march."
- The "atopic march" describes how infants with eczema are at increased risk for developing a food allergy, or related allergic condition, later in life.
- Tran’s study further expanded knowledge of the "atopic march" by focusing on infants with both eczema (atopic dermatitis) and allergic sensitization.
What is Allergic Sensitization?
If a child is sensitized to a particular food, this means that their body forms specific immunoglobulin E (IgE) antibodies towards that food, but does not develop symptoms of an allergy after that food is ingested.
- A positive skin prick or blood test result to a food that your child has eaten without any problems, or has never eaten, indicates sensitization to that food.
- Sensitization to a food increases the likelihood that a person will develop an allergic reaction when they eat that food later in life. However, not all sensitized individuals develop allergies.
- In Tran’s study, allergic sensitization was identified through a positive skin prick test to egg white, cow’s milk, peanut, soy, or one of 6 airborne allergens.
- According to results from this study, when an infant has both eczema and allergic sensitization at age one, they are at a 33 times greater risk of developing a food allergy by the age of three. This is a dramatically increased risk compared to infants with neither condition.
- Babies with eczema at age 1, but no sensitization, are at 4 times greater risk of developing a food allergy by age 3, compared to babies without eczema. (This is after adjusting for other traits that influence food allergy risk.)
- Babies with sensitization at age 1, and no eczema, are at 16 times greater risk of developing a food allergy by age 3, compared to babies with no sensitization. (Again, this is after adjusting for other traits that influence food allergy risk.)
- In another study based on CHILD data, Tran reported that not feeding a child milk, eggs, and peanut until after their first year of life "was associated with significantly increased odds of sensitization" to these foods at one year of age.
- Thus, early allergen introduction (introducing these foods before one year of age) lowers a child's risk of sensitization.
Peanut Allergy and Timing of Introduction: Findings from CHILD Data
Another JACI study conducted by Elinor Simons, MD, and others examined CHILD data on more than 2600 Canadian children. Most of these children were considered to be at low risk for peanut allergy.
- Compared to infants who were introduced to peanut within their first 12 months of life, infants who did not eat peanut during their first year of life were over four times more likely to develop a clinical peanut allergy by age three.
- Children who did not consume peanut before 18 months were over seven times more likely to have clinical peanut allergies or sensitization, compared to children who started eating peanut before 9 months of age.
- (Remember that, as mentioned above, sensitization to a food increases food allergy risk.)
- None of the infants who consumed peanut by six months of age developed sensitization to peanut by age three.
Recommendations Based On These Findings
Start Allergen Introduction Early
- Dr. Elinor Simons, the study's lead researcher, recommends that children be introduced to peanut within their first year of life, to lower their risk of developing a food allergy.
- "If peanut is not introduced before 12 months, it should still be introduced as soon as possible,” emphasizes Dr. Simons.
- Even children at low risk of peanut allergy will benefit from early peanut introduction, starting before 12 months of age.
- So, infants should be introduced to peanut within their first year of life, regardless of food allergy risk.
- Dr. Simons continues, “The CHILD Cohort Study children are from the general population and most are not at high risk of peanut allergy, whereas some of the best-known studies on the timing of peanut introduction focus on children at the highest risk of developing peanut allergy.”
- She concludes, "We know that some parents are still worried about giving their infants potentially allergenic foods. This study’s findings should reassure parents, caregivers and healthcare professionals about the benefits of early peanut introduction for all children.”
- Dr. Simons’ findings demonstrate that avoiding allergenic foods like peanut increases the risk of sensitization.
- The above “atopic march” findings by Tran and others show that eczema and sensitization together drastically increase food allergy risk.
- Thus, it is especially important to introduce infants with eczema to allergenic foods prior to their first birthday, to reduce their risk of developing a food allergy.
All health-related content on this website is for informational purposes only and does not create a doctor-patient relationship. Always seek the advice of your own pediatrician in connection with any questions regarding your baby’s health.
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About Jessica Huhn: Jessica Huhn is a content writer for Ready, Set, Food!