The Fussy Baby and Breast Milk Connection

Raise your hand if you’ve ever held, bounced, or bicycled your baby’s legs while she screamed (*hand is raised*). Parents are often warned of the impending challenges of the “fourth trimester” where baby is underdeveloped, experiencing reverse sleep cycles (sleep all day, up all night), and feeding around the clock. They may also be warned about babies and “colic,” a condition in 10-40% of infants, beginning around two weeks of age and lasting up to a year.1 Colic presents with inconsolable crying, and possibly gas, bloating, diarrhea, regurgitation, and other symptoms causing discomfort.1

Colic has been distinguished from regular infant cries based on the infant being healthy and well-nourished yet still crying inconsolably around the same time most days of the week, typically during the evening hours. According to commonly used Wessel’s criteria, this crying lasts for “at least three hours per day, at least three days per week, for at least three weeks.”2

What if baby’s extreme crying doesn’t follow Wessel’s 3-3-3 pattern? Is there anything else parents should consider if their baby cries around the clock?

Certain foods in mom’s diet may be to blame for baby’s fussiness

Mothers will likely do anything to help their fussy babies feel better, even if it means cutting out some of their flavor-packed favorite foods while breastfeeding. If it’s something in mom’s diet that is causing the baby to have discomfort, baby could start to react as early as 10 minutes after mom eats the offending food, and the food protein could stay in mom’s breast milk for up to a week.3,4

While a recent Cochrane Review found sparse evidence for effective dietary modifications for colic, there is evidence that food plays a role in non-colic-related fussiness.5 Mothers should track how baby reacts when she eats the following foods that could possibly cause fussiness in their babies.


Cow dairy (milk, cheese, or other dairy-based food or beverage) tends to be the most reactive food protein in the breast milk of nursing mothers or in formula-fed infants. Studies have found that caseins (α-S1-, α-S2-, β-, κ-caseins) and whey (α-lactoglobulin) are the most reactive protein fragments found in the highest quantities in breast milk studied in fussy babies.4,6

These studies also suggest that the amount of cow milk protein in the mother’s breast milk is dose-dependent upon mother’s dairy intake over time, so repeated exposure increases excretion into the breast milk.7-9

It’s important to note that cow’s milk allergy (CMA) has been diagnosed in infants as young as 3 months old, and it can cause an anaphylactic reaction.7 Infants and children with CMA react to a different whey protein (β-lactalbumin) than infants who just present with gastrointestinal symptoms and fussiness.7 Infants and children with CMA may show signs of respiratory, skin, gastrointestinal, and possibly anaphylactic symptoms.7 Of note, goat milk protein is often cross-reactive in children with CMA and is just as allergenic.10

Cruciferous veggies, allium veggies, and more

While there is not an overwhelming amount of evidence for many other vegetables or animal proteins causing colic-like symptoms in exclusively breastfed infants, one survey of 272 mothers regarding their 273 babies provided subjective evidence of a correlation.11 Mothers surveyed believed their babies reacted to breastmilk when they ate cabbage, cauliflower, broccoli, and onion.11 They also noted reactions to beef, cow’s milk, and chocolate.11


Many of us are familiar with wheat avoidance through gluten-free diets. Gluten is comprised of two protein subunits, gliadin and glutenin.12 The gliadin subunit has been shown to be a possible causative protein in mother’s breast milk in fussy infants.12 Researchers conclude that gluten (gliadin) passes through breastmilk, and there is no correlation with regard to quantity consumed and the amount excreted into milk.13


Peanut allergies are a frequent topic in school-aged children, and it’s not uncommon for peanuts and tree nuts to be banned from schools. One study provided 50 grams of dry-roasted peanuts to 23 breast-feeding women and then analyzed their breast milk at intervals following consumption.14 Researchers found peanut protein in 11 of 23 subjects’ samples within 2-6 hours of consumption.14 Another study provided 30 grams of peanuts to two lactating women and found peanut protein in their breast milk just 10 minutes after ingestion.15


A randomized, blinded, crossover, interventional study analyzing the breast milk of 41 lactating mothers found that the amount of ovalbumin (egg protein) found in mother’s breast milk was the same whether a whole raw egg, a whole cooked egg, or a half-cooked egg were consumed.3 Egg protein was found in the breast milk at the 2-hour, 4-hour, and 6-hour postconsumption intervals. Egg excretion in breast milk peaked around the 2-to-4-hour postintake marks, and 24% of the breast milk samples (10/41) still had ovalbumin protein at the 8-hour interval testing.3


Anecdotally many parents share their dairy-sensitive baby may also be sensitive to soy. In a mouse study, mice who were sensitized to cow milk protein were then fed soy protein and found to have immediate signs of sensitivity in both blood tests and skin tests.16

If all else fails…

If mom is apprehensive to remove foods from her diet, or if eliminating foods hasn’t helped to ease the crying, here are some concrete suggestions for how to decrease baby’s stimulation and help reduce baby’s crying:

  • Turn down loud music and avoid rattling or musical toys
  • Dim the lights in the room
  • Have young siblings or pets go to another room, if possible
  • Avoid strong smells from cooking, perfume, cologne, etc.
  • Rock the baby gently, rather than jiggling or vigorously bouncing2

For more information on pregnancy and general wellness topics, please visit the Metagenics blog.

This content is not intended as a substitute for professional medical advice, diagnosis, or treatment. Individuals should always consult with their healthcare professional for advice on medical issues.


1. NHS UK staff. Available at Accessed August 12, 2019.
2. Pepper G et al. Proc Biol Sci. 2006;273(1601):2675–2679.
3. American Pregnancy Association staff. Available at Accessed August 12, 2019.
4. Jednak MA et al. Am J Physiol. 1999;277(4):G855-861.
5. American Pregnancy Association. Accessed November 10, 2020.
6. Lete I et al. Integr Med Insights. 2016;11:11–17.
7. Firouzbakht M et al. Ayu. 2014;35(3):289–293.
8. National Institutes of Health’s Office of Dietary Supplements staff. Available at Accessed August 19, 2019.
9. staff. Available at Accessed August 19, 2019.
10. Ozgoli G et al. Int J Prev Med. 2018;9:75.
11. Bustos M et al. Auton Neurosci. 2017;202:62–72.

Submitted by the Metagenics Team

Leave a Reply

Your email address will not be published. Required fields are marked *

This site uses Akismet to reduce spam. Learn how your comment data is processed.