Can There Be Gluten in Your Breast Milk?

Yes, it's true: When you eat one of the three gluten grains—wheat, barley, or rye—the gluten protein passes through your digestive system and appears in your milk. 

Medical studies have actually confirmed this. In the first study, researchers fed 53 women a total of 20 grams of gluten (the equivalent of about six-and-a-half slices of wheat bread) and then analyzed samples of their breast milk. They found gluten in 54 out of 80 samples, and levels of gluten were highest in the samples taken between two and four hours after the women ate the gluten.

In the second study, researchers tested women following a normal, gluten-containing diet. They found the gluten protein in all 64 milk samples they tested, in levels that varied pretty widely between 0.01 parts per million and 18 parts per million (here's what parts per million means, and how much might be safe).

Those researchers also tested milk from six women who followed the gluten-free diet for three days and found their milk still contained the gluten protein. There didn't seem to be any relationship between the amount of gluten-containing foods the women ate and the amount of gluten protein in their breast milk.

Why Does This Occur?

Doctors believe gluten (and other potentially allergenic substances in our diets, like peanuts) pass through into breast milk for a reason: to "train" a baby's young immune system to cope with them.

In most cases, this works like it's intended to work, and babies' immune systems learn not to worry about these proteins. But in a few babies, it might backfire, leading to allergies and possibly even to the beginning stages of celiac disease.

The vast majority of young children aren't diagnosed with celiac disease until they've begun gluten-containing solid foods, such as bread and crackers. But there are certainly a few babies and toddlers whose mothers find they seem to react to their breast milk, and in some of those cases, the mothers have solved the problem by eliminating allergens from their own diets—most commonly cow's milk, but sometimes gluten, as well.

Celiac Babies and Toddlers Need Gluten-Free Breast Milk

If your baby or toddler has been diagnosed with celiac disease and you're still nursing, your breast milk must be gluten-free, which means you need to give up gluten-containing foods, too. (Your alternative, of course, is to wean your child so that you don't have to make a major dietary change.)

Mothers who are breastfeeding fussy babies who haven't been diagnosed with celiac disease, but who still seem to react to breast milk, should consider working with their pediatricians on an elimination diet or another solution to the problem. (As all mothers know, some babies are just fussier than others, and the cause may not be your diet at all.) 

Doctors used to think that breastfeeding helped to prevent celiac disease in babies who carry the celiac genes. Unfortunately, further research found this didn't pan out: breastfeeding (while still the healthiest choice in general) didn't help the children avoid a celiac diagnosis.