CMPA in the Breastfed Baby & How Long Does Dairy Really Stay in Breastmilk?

It's not uncommon for parents to be told it takes 2-6 weeks for dairy to leave breastmilk (depending on the advice giver). This can naturally lead to some parents choosing to switch to a hypoallergenic formula, with the belief this will result in a more rapid removal of milk proteins for baby and thus relief of symptoms.

It's of course therefore that we're basing such a big decision on an evidence base, but this is actually where the problems begin.

"β-lactoglobulin (β-Lg), which is not expressed by humans, has often been monitored as a cow's milk marker. With specific concern to cow's milk allergens, exogenous β-Lg has been detected in only a limited number of mothers' milk samples, and its presence is not related to atopic or non-atopic conditions."

The search for cow's milk allergens in breast milk has been the subject of fervent research. Human and bovine β-casein, αs1-casein, and α-lactalbumin share a medium to high degree of sequence homology (53, 31, and 73% homology, respectively) and, hence, a certain immune cross-reactivity" (1)

There's a lot more info on the link I'll drop below, but in short - the protein they were tracking, doesn't appear to be linked to symptomatic babies. Symptoms didn't correlate with the appearance or removal of this, and many mothers didn't consistently show it in their milk.  Oops

Scientists of course got back on it, and identified peptides fragments - or teeny tiny bits of broken down proteins, which both appeared to correlate with consumption AND symptoms.

They found that peptides could be identified very rapidly after consumption, leaving milk quickly  with a maximum of 6 hours recorded in a 2019 study.  Authors established peptides, not proteins was a far more effective way of tracking a constituent via breastmilk and thus future studies can explore this further for other food groups.  

"Dietary peptides were already detected at 1 h (T1) after the consumption of cow's milk and peaked after 2 h, whereas none of them was detectable 6 h (T5) after the oral load." (1)

This means there is very little delay removing dairy when mum stops eating it.

This blogger and mum of a baby with allergies, who also happens to hold a Ph.D. in Cellular and Molecular Biology got digging when they were diagnosed:

"What I found was SHOCKING.
It typically takes 2-8 hours for breast milk to be clear of food allergens after ingestion.
Ingested food allergens do not always make their way to breast milk. 

Mind. Blown. Scientists have conducted several studies of breast milk at different time intervals after ingestion by the mother. For instance, one lab gave 23 women a serving of peanuts. Only half of them ended up with detectable levels of peanut protein in their milk. The milk that did contain the allergen peaked in concentration between 1-2 hours and steadily decreased from there [1].

So why didn’t my doctor tell me this?

The question emerges: WHY would doctors say it takes 2 weeks? WHY would online articles spread this lie?
I believe the answer is two-fold. First, scientific research explains that it may take up to 2 weeks for the infant to be clear of symptoms. This is the case whether the child is placed on hypoallergenic formula OR breastmilk in conjunction with an elimination diet (let’s call this hypoallergenic breast milk). So, while mothers may be clear of allergens, their infant will likely continue to show symptoms for a few more weeks."

Her blog is great, well referenced and worth a dig around if you have a baby with allergies.

Why do symptoms persist for 2 weeks if I slip up and have dairy then?

It can take up to 4 weeks for the intestinal mucosa to heal after it has been exposed to an allergen. This may be more rapid in babies receiving breastmilk due to the growth factors and pre/probiotics, anti-inflammatory constituents etc (2,3)

In practice if dairy is the issue, we see a very rapid response via breastmilk removal, which echoes the science above.

This means parents can be confident that once they stop consuming dairy, their breastmilk is rapidly clear and they can continue breastfeeding if they wish.

1. Picariello G, De Cicco M, Nocerino R, et al. Excretion of Dietary Cow's Milk Derived Peptides Into Breast Milk. Front Nutr. 2019;6:25. Published 2019 Mar 12. doi:10.3389/fnut.2019.00025
2. Brill H. Approach to milk protein allergy in infants. Can Fam Physician. 2008;54(9):1258–1264.
3. Czerwionka-Szaflarska M, Łoś-Rycharska E, Gawryjołek J. Allergic enteritis in children. Prz Gastroenterol. 2017;12(1):1–5. doi:10.5114/pg.2017.65677

Give cow's milk to newborns, you're having a giraffe?

I know I was blogging about KMC, but as this news flash was shared on a list I read; I felt I HAD to blog it.

The headline reads:

Cow’s milk good for newborns.

Mothers who feed their babies cow’s milk in the first 15 days of life may be protecting their children from dangerous allergies later on, says a new study.

Perplexed I read on:

Women who regularly (daily) introduced their babies to cow milk protein early, before 15 days of life, almost completely eliminated the incidence of allergy to cow milk protein in their babies.

 says Prof. Yitzhak Katz of Tel Aviv University’s Department of Pediatrics, Sackler Faculty of Medicine.

Before he is apparently quoted as saying in one article:

Although the exact amount is still unknown, the paediatrician suggests a single bottle-feed at night for those mothers who are breastfeeding.

Now perhaps I'm overly cynical, but at this point alarm bells started ringing.  Any paediatrician with a sound breastfeeding knowledge (which one would surely assume essential to make a public statement such as this) would know the well documented effects of cow's milk protein entering the gut of a breastfed baby.

Secondly, given they claim the exact amount is unknown, making a suggestion to "give a single bottle daily" is highly unusual; not least because it contradicts worldwide recommendations which are based on extensive evidence.

So I decided to dig out the study.

The first thing I noticed?  The bottom of the study reads:

Supported by the Israel Dairy Board.

Aaah now thing are becoming clearer.  I then discovered Prof Katz - the one up there making statements, has declared a potential conflict of interest. 

Y. Katz has received research support from the Israel Dairy Board

aaaaah, bingo!  Let's think who might benefit if mothers introduced a bottle of cow's milk per day- wouldn't happen to be the dairy industry would it?

Holey data Batman!

Having tracked down a full copy of the study, I set down for a proper read....

What's jumps out as immediately really quite worrying is how this research has been misreported.

Science daily reads:

Many doctors suggest that whole cow's milk be avoided in the early months of an infant's feeding.  But new research from Tel Aviv University says that mothers who feed their babies cow's milk in the first 15 days of life may be protecting their children from dangerous allergies later on.

But the research never mentions whole cow's milk - it is discussing standard cow's based breastmilk substitutes when it refers to exposure to cow's milk protein.  Given all recognised health bodies state whole milk is NOT suitable for infants under six months due to health implications - what are the risks of reporting such as this?

Anyway moving on, as I'm far from finished!

The thing to remember here is that out of 13,019 infants - 66 infants were given diagnoses of IgE-cows milk allergy, with 48 patients fulfilled all criteria.

 59 patients were on a soy diet on the first examination for a period ranging from 16 to 120 days (4 months)

6 were fed with extensively hydrolyzed milk

and 1 consumed an amino acid–based formula

Total: 66

So where are the allergic babies breastfed for six months as per all recommendations?  The gut closes around this time, preventing cow's milk protein entering the bloodstream and thus is very significant in terms of allergy analysis.  The longest any mothers were breastfeeding who had allergic children can only be four months, as all 66 were on some sort of breastmilk substitute at their examination. 

Oooh hang on, here we go - the lowest risk after the first 2 weeks is when it's introduced at 6-7 months.

We do not have data to substantiate an explanation as to why the risk for IgE-CMA decreased for those exposed in the oldest age group (group IV) compared with the prior period (group III).

So, when prof above was suggesting all mums give a bottle per day, he should surely have specified if not within two weeks, wait until six months.  Weirdly he didn't - but again, that obviously wouldn't be because the study was funded by the dairy industry!

I also find it quite strange that ALL allergic infants were on non bovine breastmilk substitutes at their first examination.  Surely if a mother exclusively breastfed for say 3 months, then introduced cow's milk protein and found her child was allergic - would she not just cut that supplement back out and return to breastfeeding?  Why are all by 4 months at the latest on a substitute?

Then we get down to the bones of the paper and realise all the reporting is actually very misleading.  Researchers were:

Conducting a large-scale prospective study analyzing Cow's Milk Allergy  that was exclusively IgE mediated 

To do this they used the skin prick method..

The UK Dairy Council States:

Skin tests: this involves using either a test lancet or needle, which is first pricked in the food and immediately afterwards in the skin. The value of this test is limited since it measures only IgE mediated reactions and thus will yield negative results in non IgE mediated allergic responses. 

So researchers really were only searching for IgE allergies, as reactions caused by other antibodies cannot be detected through skin prick tests.  But, um, what about all the babies with a non IgE mediated allergy?  Where do they fit in the "give a bottle a day prevents cow's milk allergy" plan?

IgE-mediated allergy is the one many of us have heard about; the immediate hypersensitivity reaction including: hives, swelling, vomiting or anaphylaxic shock.  The last reason being one stated as to why the study is important - yet many sources state this extreme reaction is rare with dairy allergy compared to other food allergies.

The problem is that Non IgE-mediated allergy is actually far far more common.  It primarily affects the gastrointestinal tract and causes symptoms such as nausea, intestinal discomfort, diarrhoea and respiratory problems.  The damage to the tract results in a number of different allergic disorders including: gastroenteritis, milk-induced enterocolitis syndrome, proctocolitis syndrome, and allergic eosinophilic esophagitis.  These conditions can lead to pain, recurrent illness, poor growth, delayed development and failure to thrive.”

The British Medical Journal contains guidelines for the diagnosis and management of cow’s milk protein allergy in infants, so let's see what they say!

*clears throat*

Between 5% and 15% of infants show symptoms suggesting adverse reactions to cow’s milk protein (CMP),1 while estimates of the prevalence of cow’s milk protein allergy (CMPA) vary from 2% to 7.5%. Differences in diagnostic criteria and study design contribute to the wide range of prevalence estimates and underline the importance of an accurate diagnosis

Cow's Milk Protein Allergy may be immunoglobulin E (IgE) or non-IgE associated.

Whether breastfed or not, the guidelines go on to state:

Elimination diets and challenges are the gold standard for diagnosing CMPA

I wonder why researchers (supported by the dairy industry) might totally ignore more common non IgE cases?  hmmmm... oh no, wait!  Here it is:

In 381 cases the parents either complained about adverse effects that they considered CMP related, or alternatively, these parents avoided CMP exposure despite having discontinued exclusive or almost exclusive breast-feeding. A causal relationship between the complaint and CMP was ruled out in 244 cases among these infants.  In 71 cases, which will be described separately, a diagnosis of non–IgE-mediated adverse reaction to CMP was established

Right so where is the discussion about these infants?  how were they fed? How exactly did researchers rule out 244 cases and confirm 71 cases - did they use the BMA "gold standard".

All 381 parents of infants in whom an adverse reaction to CMP was suspected were interviewed by one of the investigators (N.R.), and their infants were invited for an examination

I guess that's a no then.  I can't find a single resource that claims non IgE allergy can be confirmed or denied by a chat and a physical exam!

In contrast to this study, two pieces of older research (not funded by the dairy industry) found that in susceptible families, breastfed babies can be sensitised to cow’s milk protein by the giving of just one bottle of bovine based formula in the first three days of life (Host, Husby & Osterballe)

Another found that when Serum IgE concentration was measured on the 5th day, high levels indicated a higher risk of developing allergic manifestations in formula-fed babies.  Family history was also significant. Manifestations suggestive of food allergy were hardly observed in breast-fed babies.  (Vandenplas & Sacre)
  
Ultimately, even if researchers really believe that exposure in the first two weeks could prevent rare IgE allergy; we know non IgE allergies are more common,  a lot harder to diagnose and cause conditions just as serious long-term.   Furthermore as discussed above, the gut of an infant changes with the introduction of bovine protein, increasing risks of a much wider range of conditions.  To suggest infants be given a bottle of cow's milk on the basis of this one study, is not only irresponsible, but really quite scary!