Liquid Energy

& Liquid Gold


Can Coffee Cause Reactions?

If you believe coffee consumption is the source of your infant intolerance/allergy symptoms this article is for you!  First, be sure to rule out any potentially linked culprits.  Creamers, for example, may be the root of the problem.  Many dairy, soy, nut, and grain based coffee add-ins can often cause infant woes.  Consider this even if you drink your coffee black but share a work vending machine which dispenses these creamers.  Once you have ruled that out, let's dig into the science behind our favorite beverage and how it may (or not) impact your liquid gold. 


A 2018 infant caffeine effect meta-analysis found only 5 publications that met exclusion and inclusion criteria [1].  Considering the prevalence of caffeine consumption [sips coffee] you would think this topic would be more readily studied with quality analysis.  Of these few scientific trials, many ended up being unclear as to whether the small number of infant behavior changes were related to the stimulant or other ingredients in the food/beverage.  For example, a 2011 study found that 18 of 67 participants experienced increased atopic dermatitis to chocolate and only 7/67 to coffee which led researchers to believe the caffeine was not the culprit [2].  

Okay, so the research on infant impact is sparse at best.  Let's look instead at actual concentrations!  One interesting study gave lactating mothers 750 mg of caffeine daily (that is over 7 cups of coffee!) for 5 days and continued to analyze breast milk concentrations for an additional 4 days after.  The average concentration of day 5 milk samples was 4.3ug/ml [3].  To compare, a cup of coffee is approximately 421.9ug/ml (math shown below).  This, and similar subsequent studies, show that a minuscule amount transfers to human milk [4].  Since you are not likely consuming 7 cups of coffee and the dilution factor is so high, your infant reacting to caffeine through breast milk is improbable.  

Cup of coffee:  100 mg per 8 oz
8 oz = 237 mL
100 mg / 237 mL = 0.4219 mg/mL
0.4219 mg/mL = 421.9 ug/mL

Coffee Protein? 

Dried green coffee beans are made up of around 10% protein.  During the roasting process, these "11-S Storage" proteins are mostly degraded down to their individual amino acid bases and even further still to the products of amino acids [5].  The concentration of amino acid and by products vary widely depending upon the bean.  Due to the degradation process in roasting, it is very unlikely your little one is reacting to coffee protein.

Interestingly, coffee extract has been shown to have anti-inflammatory affects wherein it protects against the denaturation of other proteins [6].  For those who have read our ladders article, this means that even though the creamer you added to your coffee may be then "heat treated" my the warm liquid, coffee actually protects the protein from being broken down.  This is believed to be due to polyphenols contents of coffee. 

Coffee Histamine?

Coffee is high in histamine which can set off an inflammatory reaction for some individuals.  Histamine sensitivity is often correlated to a condition known as Mast Cell Activation Syndrome (MCAS) which impacts about 1 in 10,000 people [7].  Mast cells are an important part of the immune system which can become defective and overproduce "mediators" which cause many food allergy-like responses.  Learn more about MCAS, diagnosis, and treatment here.  


While it is feasible that ingested histamines would transfer to human milk, there are little to no studies looking specifically into this.  Interestingly, a 2016 study found that mastitis was linked to significantly elevated human milk histamine level [8].    


If you have suffered from mastitis and saw a massive change in food intolerance/allergy symptoms or have experienced issues related to the high-histamine list specifically, you may want to consider talking to your doctor about MCAS.  You can find a great list of high and low histamine foods here.

Have you breastfed a child with MCAS?  We would love to hear more about your journey to help fellow nursing mothers here.  


  1. McCreedy, Aimee, et al. "Effects of maternal caffeine consumption on the breastfed child: a systematic review." Swiss medical weekly 148.3940 (2018).

  2. Uenishi, Toshiaki, et al. "Aggravation of atopic dermatitis in breast‐fed infants by tree nut‐related foods and fermented foods in breast milk." The Journal of Dermatology 38.2 (2011): 140-145.

  3. Ryu, Jacqueline E. "Caffeine in human milk and in serum of breast-fed infants." Developmental pharmacology and therapeutics 8 (1985): 329-337.

  4. Aresta, Antonella, Francesco Palmisano, and Carlo G. Zambonin. "Simultaneous determination of caffeine, theobromine, theophylline, paraxanthine and nicotine in human milk by liquid chromatography with diode array UV detection." Food Chemistry 93.1 (2005): 177-181.

  5. Montavon, Philippe, Anne-France Mauron, and Eliane Duruz. "Changes in green coffee protein profiles during roasting." Journal of Agricultural and Food Chemistry 51.8 (2003): 2335-2343.

  6. Chandra, Sangita, et al. "Evaluation of in vitro anti-inflammatory activity of coffee against the denaturation of protein." Asian Pacific Journal of Tropical Biomedicine 2.1 (2012): S178-S180.

  7. Akin, Cem. "Mast cell activation syndromes." Journal of Allergy and Clinical Immunology 140.2 (2017): 349-355.

  8. Perez, Marta, et al. "Mastitis modifies the biogenic amines profile in human milk, with significant changes in the presence of histamine, putrescine and spermine." PloS one 11.9 (2016): e0162426.

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