The relationship between nutrition in the first 3 days of life and allergies
An intriguing and unique article that was published online at the respectable journal – JAMA pediatrics on December 2019, PMID 31633778.
The rational for this study is that it is known that the prevalence of cow milk protein allergy specifically and allergy of many other foods in general, is increasing over the last few years. In families where there is a high chance for a baby to develop food allergies, some recommend exclusive breast feeding or supplementing with elemental formula.
On the other hand, some studies demonstrated that by given cow milk based formula during the first 2 weeks of life, the prevalence of cow milk protein allergy – decreases.
The researchers choose to focus on early intervention, on the first 3 days of life, in order to ask a controversial question – is it right to give babies which are at a high risk for developing food allergies, milk based formula or an elemental formula (as an addition for breast milk off course), as early as in the first 3 days of life? Will this approach affect the prevalence of other foods later on?
Methods – this study was conducted in Japan between the years 2013-2018. Babies after birth were divided into 2 groups by nutrition type, for the first 3 days in life:
Group 1: fed from breast milk and elemental formula exclusively. The babies continue with this form of nutrition for the first few months of life. If the baby reached an amount above 150 ml per day of supplemental formula, than he switched to cow milk based formula. Therefore, by definition, these babies did not receive any cow milk protein at least for the first 3 days of life (and for some of them – for a longer time).
Groups 2: fed from breast milk and cow milk based formula (a minimum dose of formula than was set in advance according to age).
Notice that the intervention was done only on babies with a high risk of developing allergy, meaning babies with at least one first degree relative with atopy (asthma, atopic dermatitis, food allergy, allergic rhinitis, act.). Excluded from the study were babies which parents selected nutrition by breast milk or cow milk based formula exclusively. Also excluded – preterm or babies with underlining illness.
Randomization was done by a computer.
Follow-up was done meticulously until the age of 2 years, including allergy testing (blood workup for specific antibodies as well as challenge test for different foods and questionnaires). Sensitivity for different allergens was also tested, including cow milk protein, egg protein, wheat, dust mite and more.
Results – 156 babies were recruited for each study group. 5 participants in each group were lost to follow-up. The groups were similar in every demographic characteristics, including – type of allergy, birth week and birth weight, form of delivery (vaginal or cesarean), and more.
Interestingly, the children in the cow milk formula group had twice the chance of suffering from cow milk protein allergy (positive lab testing and matching clinical events) in the age of 2 years.
There was no difference in the prevalence of allergy that’s’ determined in a lab test between the two groups. Nonetheless, the prevalence of food allergies (not just cow milk protein), which are not lab-proven was lower in the elemental formula group.
You can see that in the elemental formula group, the sooner that the introduction of cow milk protein was done, the antibodies for the protein was higher.
The authors reached the conclusion that introducing cow milk protein at least after the 3 day of life lowers the prevalence of cow milk protein allergy.
Discussion – this is an original work, which puts a spotlight on an important subject – food allergies in children. These findings are impressive and demonstrate a significantly lower prevalence of allergies in the groups of babies which avoided cow milk protein for at least 3 days since birth.
How can this be explained? Researchers hypostasized that early exposer to cow milk protein can raise antigens in the blood stream and bring to a rise in antibodies formation and allergies in the future.
How does avoiding cow milk protein in the first 3 days prevents that? There are no good explanations.
Remember that there are some limitations to this study. Amongst them:
– The intervention was done in the group of high risk babies, which had a greater chance of developing allergies. Meaning, you cannot make a sweeping recommendation saying every baby needs to avoid cow milk protein in the first days of life.
– There is a debate on what is the gold standard lab test in proving allergy in children. Sometimes lab results are not indicators of allergy in real life. However, difference was found between the two groups, clinically and in the lab results.
– Other factors can affect allergies in children, which were not examined in this research. For example, receiving antibiotics after birth.
– It is hard to say what worked in this study. Avoiding cow milk protein for at least 3 days, or giving elemental formula. However, at the end of the day, both interventions are on the same spectrum.
So what to do?
– Breast milk is the best nutrition for that baby, in families with or without atopy.
– As a supplement or substitute for breast milk, in families with atopy – the results of this study may be enough to base a recommendation from leading health organizations, advising starting elemental formula at once, without trying cow milk base formula first. According to the authors, this is a simple, cheap intervention, which can lower allergy prevalence.
Those of you who want to read more about cow milk protein allergy can read this next post.
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