Tummy Troubles, Colic, and Mama’s Diet

This question comes from a ScienceofMom reader, who wrote me to ask:

I’m looking for good quality information on whether mom’s diet can really cause tummy trouble in babies, outside of perhaps a milk protein allergy.  I’ve seen arguments that it does, but they seem largely anecdotal.  Yet my pediatrician has never mentioned the possibility that my diet might be causing my 3-month-old infant to have gas bouts at 4 a.m. or so every. single. night.  Instead I’m routinely told that I just need to wait and by 4 months her digestive system will grow up.  –KT

Most of us have heard and read that we don’t need to give up any of our favorite foods in order to breastfeed our babies. In general, this is true, and it is an important message. Between sore nipples and engorged breasts during those first few weeks of motherhood, moms need to know that breastfeeding will eventually (usually) be an easy fit to their lifestyle.

There has even been some recent research showing that maternal diet restriction during lactation may increase baby’s chances of developing allergies. If your baby is NOT showing any signs of tummy troubles, your best bet is to eat a balanced variety of whole foods. Think of it as gently introducing your baby to the proteins of the world via your milk.

However, there have been several studies of the effect of mom’s diet on colic symptoms. Approximately 1 in 5 U.S. infants between 0 and 4 months are considered to have colic. The “Rule of Threes” is used to define colic: A colicky baby has incessant, inconsolable crying for at least 3 hours per day on at least 3 days per week, for more than 3 weeks. Crying is usually the worst in the evening hours. {It isn’t clear from K.T.’s note if her baby actually has colic or just gas – they’re not always the same. I’ve focused this post on colic, because that’s where the research is, but I’m willing to speculate that what works for colicky babies may also help babies with milder types of GI discomfort.}

The truth is that we really don’t know what causes colic. It is probably multi-factorial and has different causes in different babies. (For an interesting account of the history of our understanding of colic and how to manage it, check out this article,The Colic Conundrum, from The New Yorker.) However, there are several lines of evidence that colic is related to intestinal immaturity or imbalance. Colicky babies often seem to be gassy and to have GI discomfort, pulling their legs up to their bellies while crying as if in pain. Research has also shown that colicky babies have intestinal inflammation and abnormal gut motility [1]. In addition, we know that proteins from mom’s diet can pass into breast milk, and some babies seem to be allergic or intolerant of these proteins. That’s where the role of mom’s diet comes in.

Cow’s milk appears to be the most common culprit when it comes to food allergies in infants. It has been estimated to occur in about 0.5-1.0% of exclusively breastfed infants [2]. Studies on the relationship between cow’s milk allergy and colic are mixed, however. In one study, 66 mothers of exclusively breastfed colicky infants eliminated cow’s milk from their diets, and “colic disappearance” was noted in more than half of the infants [3]. When the moms later drank cow’s milk again as a test, colic symptoms returned in 2 out of 3 of the babies. Based on this study, cow’s milk allergy or intolerance would seem to be an important cause of colic. Continue reading