Child’s food preferences could be determined in womb: Study

By Dr. Ananya Mandal, MDAug 10 2011

According to the latest research from Monell Chemical Senses Center mothers can influence a baby's palate and food memories before it is born. The study finds that what a woman eats during her pregnancy shapes the baby's food preferences later in life.

It is known that within the womb the baby is surrounded and nourished on the amniotic fluid, which is filled with the flavors of what the mother has eaten. Julie Mennella, a researcher at Monell said, “Things like vanilla, carrot, garlic, anise, mint -- these are some of the flavors that have been shown to be transmitted to amniotic fluid or mother's milk.” The babies are feasting on the flavored amniotic fluid, forming memories of these flavors even before birth. These memories result in preferences for these foods or odors for a lifetime.

Researchers speculate that very early exposure to flavors, before and after birth, and reinforcement of those flavors make it more likely that children will accept a wide variety of flavors. Researchers say this helps explain why kids from countries with more adventurous menus enjoy more diverse foods than a child exposed to American peanut butter and jelly and chicken nuggets.

Dr Mennella’s study appeared in the journal Pediatrics. Her research involved giving pregnant women garlic or sugar capsules and asking a panel to smell and identify samples of the women's amniotic fluid. “And it was easy,” she explained. “They could pick out the samples easily from the women who ate garlic.” The sense of taste is actually 90-percent smell, she added, so they knew just from the odor that the babies could taste it.

Mennella says she got the idea from dairy farmers, who in the 1960s and 70s were doing research on how the diet of the dairy cow impacted the flavor of the milk. She says cows that graze on wild garlic and onion, or who live in stinking barns, produce milk with distinct flavors.

But Mennella says that not only is the amniotic fluid and breast milk in humans flavored by food just like cows, but memories of these flavors are formed even before birth. That could result in preferences for these foods or odors for a lifetime.

Mennella said this had already been observed in rabbits, so she decided to test it in human babies — with carrots. Pregnant women were divided into three groups. One group was asked to drink carrot juice every day during their pregnancy, another during breastfeeding and a third to avoid carrots completely. Then when the children began to eat solid food, researchers fed them cereal made either with water, or carrot juice and videotaped their responses.

“And just like the European rabbit, the babies who had experienced carrot in amniotic fluid or mother's milk ate more of the carrot-flavored cereal,” said Mennella. “When we analyzed the video tapes they made less negative faces while eating it.”

This makes a lot of evolutionary sense, says Mennella. Since mothers tend to feed their children what they eat themselves, it is nature's way of introducing babies to the foods and flavors that they are likely to encounter in their family and their culture. “Each individual baby is having their own unique experience, it's changing from hour to hour, from day to day, from month to month…As a stimulus it's providing so much information to that baby about who they are as a family and what are the foods their family enjoys and appreciates,” she said.

University of Florida taste researcher Linda Bartoshuk says babies are born with very few hard and fast taste preferences. She says Mennella's work shows that very early exposures to flavors – both before and after birth — make it more likely that children will accept a wide variety of flavors. And when those early exposures are reinforced over a lifetime, Bartoshuk thinks they might have far-reaching implications, even promoting good eating. “To what extent can we make a baby eat a healthier diet by exposing it to all the right flavors — broccoli, carrots, lima beans, et cetera? Could we do that or not? My guess is we could,” says Bartoshuk.

Menella says parents should keep exposing young children to healthy flavors because they can eventually learn to like them.