–This post is part of our 10-year anniversary series “Breastfeeding is…”—
Breastfeeding is flavor learning.
Through mother’s milk, human infants are “exposed to a bewildering variety of flavors that influence subsequent liking and choice.” [Beauchamp & Menella]
Differently, baby milk substitutes (BMS) or baby formulas offer static flavor. Formula manufacturers are only able to add flavoring to follow-on formulas at which point, it is too late to stimulate flavor detection, explains Dr. Julie Menella.
A breastfed baby experiences textural variations such as viscosity and mouth coating so “breastfeeding provides an even richer variation in oral sensory stimulation,” as recorded in Flavor Perception in Human Infants.
Before birth, flavor learning begins around the sixth month of gestation when the fetus begins to inhale and swallow amniotic fluid marking its first chemosensory experiences. [Thomas, 2022]
The flavors a baby is exposed to signal things like the flavors of one’s culture, which foods are safe to eat, and biodiversity which later impacts food choice thereby affecting overall health and wellness.
Mennella makes clear, “breastfeeding confers greater acceptance of healthy foods…only if they are part of the mothers’ diet…”
One study which looked at the effects of maternal garlic ingestion on the odor of milk and the suckling behavior of the infant, found that the nursling detected changes in mother’s milk and stayed attached to the breast for longer periods of time, sucked more when the milk smelled like garlic, and tended to ingest more milk.
Similar findings were noted when vanilla ingestion was investigated.
Just as infants can detect the flavors of healthy and aromatic foods in their mother’s milk, they can also detect those of potentially harmful substances. For instance, Menella found that “infants can readily detect the flavor of alcohol in mother’s milk but…the decrease in consumption at the breast after maternal alcohol consumption is apparently not due to the infants rejecting the flavor of alcohol in their mothers’ milk.”
It has also been found that babies can detect the flavors in cigarettes in breastmilk. Still, the researchers note, “We do not suggest that lactating women who smoke occasionally should stop nursing. However, the knowledge that the milk of mothers who smoke smells and may taste like cigarettes provides an additional reason to avoid smoking.”
As artificial sweeteners gain prevalence in the food industry, Philip O. Anderson’s How Sweet It Is: Sweeteners in Breast Milk summarizes current knowledge regarding the transmission of sweeteners into human milk.
Dr. Anne Eglash points out in a 2019 Clinical Question of the Week:
“There is preliminary research evidence that a maternal diet high in fructose may increase body weight and fat mass in breastfed infants. When mothers consume foods or beverages high in fructose, the level of fructose rises in breastmilk. This is not true for glucose, because maternal insulin rapidly normalizes the maternal glucose level after glucose ingestion. Insulin does not moderate the fructose level like it does for glucose.
And increasing sweetness of breastmilk via artificial or natural sweeteners in the maternal diet might predispose to later obesity. This may be partially mediated by an alteration in the gut microbiome by the sweeteners.”
As infants transition to complementary feeding at six months of age, the flavors they’ve already been exposed to in utero and through breastmilk will help them to explore a breadth of healthy table foods. While human milk is meant to be the primary staple of infants’ diets, human milk alone cannot provide everything babies need nutritionally, especially micronutrients like zinc and iron. [More on appropriate complementary feeding here— Food before one is NOT just for fun.]
Newer research is starting to investigate odor-active volatile compounds in preterm breastmilk and the effect of smell and taste of milk during tube feeding of preterm infants. Find some of those studies here, here, and here.
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As part of our celebration, we are giving away an online learning module with contact hours each week. Here’s how to enter into the drawings:
Email info@ourmilkyway.org with your name and “OMW is 10” in the subject line.
This week, in the body of the email, tell us: Do you have a funny infant feeding story?
Subsequent weeks will have a different prompt in the blog post.
We will conduct a new drawing each week over the 10-week period. Please email separately each week to be entered in the drawing. You may only win once. If your name is drawn, we will email a link with access to the learning module. The winner of the final week will score a grand finale swag bag.