Uncovering flavors in breast milk: Dr. Julie Mennella’s flavor learning research and implications

In case you haven’t heard, artificial baby milk increases the risk of Sudden Infant Death Syndrome, obesity and certain kinds of cancer. Formula-fed children are also at risk for contracting a long list of illnesses that might otherwise be squashed by immunities in breast milk. Among the many differences between artificial baby milk and breast milk, there is one big difference that is often overlooked: flavor.

In my Certified Lactation Counselor (CLC) training, I remember learning that children were likely to nurse longer if their mothers had recently consumed garlic. Breast milk never ceases to amaze me; especially when it’s garlic-flavored!

As a member and director emeritus of the Monell Science Apprenticeship Program, a non-profit institute in Philadelphia, Dr. Julie Mennella has been conducting flavor learning research for more than two decades.

Dr. Mennella’s research “focuses on the development of food and flavor preferences in humans and the effects of alcohol and tobacco on women’s health and infant development.”  (Retrieved from http://www.monell.org/faculty/people/mennella).

“Every baby is living in their own sensory world when they are breastfed,” Dr. Mennella says. “It’s unique food that that mom has made for that baby.”

Differently, artificial baby milk although available in many varieties, presents static flavor.

“That constant flavor doesn’t reflect the culture they will grow up in,” Dr. Mennella says of formula-fed children.

Greater implications 

Unfamiliarity with the flavors of one’s culture and consequential unacceptance of certain foods has considerable implications.

As Dr. Mennella and Dr. Gary K. Beauchamp put it in their 2011 article entitled Flavor Perception in Human Infants: Development and Functional Significance, “both before and after birth, humans are exposed to a bewildering variety of flavors that influence subsequent liking and choice.”

Their research suggests that taste and olfactory systems operate in utero within the amniotic fluid and that breast milk serves as a sort of flavor bridge to the time of weaning.

Because the food we consume directly impacts our health, it is important to note that an infant who develops a “taste” for salty, sweet and fatty foods over fruits and vegetables will have a greater risk for diabetes, hypertension, cardiovascular disease and some cancers according to Mennella’s and Beauchamp’s Flavor Perception in Human Infants article.

Dr. Mennella explains that the breastfed baby exposed to an abundance of flavors is at an advantage once weaned.

“What moms eat are typically what babies end up eating,” Dr. Mennella says. She highlights the importance of a varied diet for pregnant and lactating women.

A breastfed baby experiences textural variations such as viscosity and mouth coating as well so “breastfeeding provides an even richer variation in oral sensory stimulation” as stated in Flavor Perception in Human Infants.

Dr. Mennella says formula companies are only able to add flavoring to follow-on formulas at which point she says it is too late to stimulate flavor detection.

Benefits a plenty

Flavor learning research does not only point to future variation in diets. In The chemical senses and the development of flavor preferences in humans published in Hale and Hartmann’s Textbook of Human Lactation, Dr. Mennella cites the research of Frederick D. Provenza which shows that “learned food preferences are transmitted from [mammalian] mothers to their offspring, resulting in greater biodiversity.”

Provenza’s research also suggests that flavors transmitted through breast milk allow mammalian offspring to know what food is safe to eat through familiar flavoring once weaned.

More to discover, more to learn

Recently, Dr. Mennella has become interested in growth differences between breastfed and formula-fed infants.

“I’m shocked at how little we really do know,” she says.

Healthy Children Project’s upcoming 17th Annual Conference in Orlando will be an opportune time for Dr. Mennella to summarize some of the findings of basic flavor learning research and present some unanswered questions.

“How do we learn from basic biology to educate both mom and health professionals about the mystery of what’s happening early in life?” she asks. “We’re beginning to have evidence that it’s setting the stage for many things to come.”

Sources:
Mennella, J. A. (2007). The chemical senses and the development of flavor preferences in humans. In P.E.Hartmann & T. Hale (Eds.), Textbook on Human Lactation (pp. 403-414). Texas: Hale Publishing.

Beauchamp, Gary K., and Julie A. Mennella. “Flavor Perception in Human Infants: Development and Functional Significance .” Digestion . (2011): 1-5.

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