Updated: Apr 29, 2020
One of my biggest frustrations as a health professional is to see my colleagues stuck in the old rut.
Yeah, we used to think the food mom eats doesn't affect her breast milk. We used to think colic, eczema and spit ups were normal in babies, and that it would just go away by itself.
We used to not believe there was such thing as a food sensitivity. We used to think, if your skin prick test came out negative, your baby doesn't have a food allergy and therefore, it must all be in your head.
But now we know better. Now we have studies, scientific evidence, and oh-so-many testimonies to prove: The food mom eats DOES affect her milk, and babies CAN be sensitive to a food in mom's diet!
But so often, it is missed by doctors, pediatricians - even pediatric allergists.
The symptoms aren't always straight forward - they can affect many different parts of the body. On top of that, it often takes many hours to days for a reaction to even show, so it's difficult to make the connection to a food in mom's diet.
But it's real. Your gut feeling was right. Your breastfed baby CAN be sensitive to a food in your diet!
A Food Sensitivity differs from a true Food Allergy or Food Intolerance
There is a lot of confusion out there about what Food Sensitivities are, and how they differ from true Food Allergies or Food Intolerances.
A big part of the confusion stems from the fact that Food Sensitivities are also called non-IgE mediated Food Allergies. It's easy to confuse this term with IgE mediated Food Allergy, which is the official name for a true Food Allergy.
But, let me help you clear up the confusion:
Food Sensitivity vs. true Food Allergy
Both, food sensitivities and true food allergies are a reaction of the immune system to something in your diet, mostly proteins. The difference is how your immune system reacts to these triggers.
In a true food allergic reaction, your body reacts by producing antibodies called Immunoglobulin E (IgE). These antibodies travel to different parts of the body and bind to mast cells, which release histamine every time the offending food protein re-enters the blood stream. Histamine causes inflammation, and in serious cases this can lead to a throat closure, anaphylaxis and even death.
It is important to understand that IgE is the least abundant, but most potent antibody. Therefore, a true food allergy is rare (especially among exclusively breastfed babies), but has much more serious consequences. Even small amounts can trigger a reaction! An example of a true food allergy is a peanut allergy.
A food sensitivity, on the other hand, is also known as a non-IgE mediated food allergy. It is also a reaction of the immune system to something in your diet, but Immunoglobulin E is not involved this time. Instead, T cells trigger the release of chemicals such as Interleukins, Prostaglandins and TNF-alpha (3,4).
These chemicals then travel through the blood stream to different parts of the body where they cause symptoms such as headaches, eczema or diarrhea. The tricky part is that this reaction is much slower and can take hours or even days to show up, especially in breastfed babies since it takes a while for mom to digest the food and then to enter baby's system.
Therefore, a defining difference between a true Food Allergy (IgE mediated Food Allergy) and Food Sensitivity (non IgE mediated Food Food Allergy) is how long it takes for symptoms to show up.
In a true Food Allergy, symptoms usually come on very quickly; you may see your breastfed baby react to to your milk within a few minutes and up to 2 hours after ingesting your milk after you've eaten the offending food. In a Food Sensitivity, these symptoms can take hours to days to show up.
Food Sensitivities are common in exclusively breastfed infants, while true Food Allergies are rare and usually don't develop until the introduction of solid foods.
Food Sensitivity vs. Food Intolerance
You may now think, a Food Sensitivity sounds an awful lot like a Food Intolerance, especially if the offending food is cow's milk (Lactose Intolerance).
While it's true, a food intolerance is also rarely life threatening, the symptoms come on more slowly, and can also include diarrhea, bloating and gas, a food intolerance differs from a food sensitivity because it is actually not a reaction of the immune system at all. Instead, it is a lack of enzymes to break down certain sugars in the food.
An example of a food intolerance is a lack of the enzyme lactase to break down the milk sugar lactose, also known as lactose intolerance.
Food intolerances are more common in adults and very rare in babies.
That is not to say it is unheard of: Some premature babies may be lactose intolerant because they cannot yet produce the enzyme lactase, but this usually resolves before the baby is even discharged from the hospital. In fact, if a baby was lactose intolerant, he or she wouldn't be able to tolerate breast milk at all, even if the mother followed a dairy free diet, because lactose is the primary sugar in breast milk. Therefore, a lactose intolerance in babies is usually diagnosed very shortly after birth.
If your baby is older than 2 weeks and has not been diagnosed with a Lactose Intolerance, it's very unlikely he or she has a lactose intolerance. You are more likely looking at a food sensitivity!
The Symptoms of a Food Sensitivity involve different parts of the Body - and are NOT always easy to spot!
The symptoms of a food sensitivity in breastfed babies aren't always easy to spot - in fact, they're often missed because they can take hours to days to show up and can involve different parts of the body.
They are also sometimes misdiagnosed as something else: Tongue tie, teething or simply a 'colic-y baby' are some of the common diagnosis which could actually be a Food Sensitivity!
If your baby has any of the following symptoms, make an appointment with your baby's pediatrician and tell them you suspect your baby is sensitive to a food in your diet.
Itchy, red and swollen patches on the skin (called 'eczema') are a good indicator a food in mom's diet may be to blame. These patches usually show up on baby's cheeks, but may even travel down baby's back or belly.
Babies with a food sensitivity are often very fussy, cry more than other babies, sleep very little and in small stretches and are often labeled as being 'colic'. It makes sense, if we consider food sensitivities can cause belly and gas pains, joint pains, headaches or even migraines, and our poor babies cannot communicate them to us other than by crying!
Frankly, those aren't easy symptoms to correlate with a food sensitivity! However, baby's stool will tell you a lot about how they're handling certain proteins and substances in your breast milk:
An exclusively breastfed baby's bowel movements who is past the stage of passing meconium (the black, tarry stool newborns pass for the first couple of days of life) should be yellow-ish (like mustard) in color, is most often speckled with little seeds and actually quite runny in consistency (for a visual guide, follow this link).
A runny consistency does NOT necessarily indicate diarrhea, and is actually the norm for exclusively breastfed babies. A 'blow out', on the other hand, may be an indicator of diarrhea, as is a 'water line' around the edge of the diaper or a sudden increase in baby's bowel movements.
(A friendly note: Make sure you take baby to the pediatrician if you suspect he/she has diarrhea, as it can easily lead to dehydration).
Some babies have mucous-y (snot looking) stool as a result of a food sensitivity. Blood in the stool is (literally) a red flag for a food sensitivity. However, the blood may not be visible to the human eye! Your child's pediatrician can check for hidden (occult) blood in the office.
Again, it is important to take your baby to the pediatrician if you see any of these symptoms for a thorough check up! Tell them you suspect a food sensitivity as these are the common symptoms. He or she will most likely prescribe a food culprit elimination, guided by a specialized Registered Dietitian like myself.
Dairy - the most common Culprit
Ironically, dairy - the milk we drink that is from another species - is the most common culprit for food sensitivities in infants. Most cases of food sensitivities in breastfed infants can be resolved by following a dairy free diet.
However, a dairy free diet is not an easy switch, since it is one of the staple foods in the Western diet and also - well - 'hidden dairy' is all around us and food labels are confusing! Also, it is important, especially while breastfeeding, to assure you are not missing out on important nutrients.
That is why I've written the e-Book Breastfeeding a Baby with Dairy Sensitivity, to help you navigate the Elimination diet and Reintroduction, while maintaining a balanced diet while breastfeeding.