The elegant and complex systems of flavor and nutritional programming

— This post is part of our “Where are they now?” series where we catch up with some of our very first Our Milky Way interviewees from over a decade ago! — 

“The societal and clinical impact of promoting sustainable food habits is significant, since what a child eats determines in part what the child becomes. (Mennella, et al, 2020, p. 291)

 

The pop of poppy seeds in aloo posto, cough-inducing spice in stir-fried lotus root with chili peppers, the meaty texture of a bowl of Cuban black beans. 

The dishes we crave tell stories. 

“Our food preferences have meaning,” Julie Mennella, PhD begins. “They’re more than just a source of calories. Food preferences provide families with identity.”

[Rough Translation’s Tasting at a Distance and Forgotten Foods of NYC’s Appetite for Home — Bitter-Sweet Memories of Learning to Cook & Eat in America both present beautiful audio embodying these connections.]

Elegant and complex learning systems 

The multidimensional interactions we have with food begin with our mothers. A fetus is passively exposed to the flavors of the biological mother’s diet through amniotic fluid, and the infant goes on to interact with these flavors through human milk. Mennella and her colleagues have called this “intimate bidirectional chemosensory communication.” (Mennella, et al, 2023)

In this complex communication, “diet and xenobiotic exposures of the lactating parent, due to lifestyle choices or necessitated by medical treatments, affect not only milk production and milk composition but also the infant’s biological responses, either beneficially or adversely,” the authors continue. “Developing alongside the chemosensory signaling is the seeding and maturation of the infant microbiome, which transfers and exchanges with that of the parent and of the milk, forming additional bidirectional linkages.” (Mennella, et al, 2023

Infant formulas, although available in many varieties, do not foster this elegant exchange and where developing food preferences are concerned, present a static flavor.

“That constant flavor doesn’t reflect the culture [a child] will grow up in,” Mennella comments.  

The same goes for infants fed jarred and pouched baby foods (what we’ve referred to as “the packet apocalypse” where the convenience of “ready-to-feed-super- glop” has largely replaced the art of dining and sharing meals.) The explosion of the baby food industry means parents often don’t feed their children what they themselves eat. Families can feed their babies canned peas, but never eat a pea themselves, Mennella points out. 

Mennella’s research has always been interested in flavor and nutritional programming in humans and the development of food preferences, but over the last decade, it has diversified to ask questions about the taste of pediatric medicines from a personalized medicine perspective, determinants of sweet and salt preferences during childhood, the development of psychophysical methods to study olfaction, taste and chemesthesis across the lifespan, biomarkers for dietary intake across the lifespan, and reproductive state effects on dietary intake and weight loss in women. [Retrieved from: Monell Center

Collective, family- focused approach

Mennella summarizes a few key points from her work. 

“Children live in different sensory worlds,” she says. ”They are really sensitive to the current food environment.” 

And like she and her colleagues have written, the food environment rich in added sugar and salt that caters to preferred human taste, provides challenges for all of us. 

“Fortunately, our biology is not necessarily our destiny. The plasticity of the chemical senses interacts with experience with foods to modify our preferences, producing an interface between our biology and our culture, our past and our present.” (Mennella, et al, 2020, p. 291

In order to influence our destiny, Mennella says that the strategy can never be for the child alone. She suggests there be more attention paid to the family as a whole in order for healthy behaviors to be sustainable. 

She nods to the success of peer counseling programs and recommends bolstering these opportunities for families to interact and learn from one another. She says she envisions primary care taking on a community approach to provide not only a forum for education but also opportunities for interaction between families.  

Where science and policy meet 

Mennella recognizes that ultra-processed, convenience foods are palatable and often inexpensive and deems this a “much bigger issue.” 

Her research has guided national and global health initiatives like the USDA and HHS Pregnancy and Birth to 24 Months (P/B-24) Project, the Breastmilk Ecology and the Genesis of Infant Nutrition (BEGIN) Project, and the World Health Organization’s (WHO) Commission on Ending Childhood Obesity. [WHO recently released its new guideline for complementary feeding of infants and young children 6-23 months of age. Read about it here.]  

As science evolves– where the picture gradually becomes more crisp and for every one question asked, fifty more arise– policies and practice must reflect and catch up to the robust body of evidence in order to best support child and family health.  

Read our 2012 coverage with Dr. Mennella here



Leave a Reply

This site uses Akismet to reduce spam. Learn how your comment data is processed.