June 6, 2001 -- Pregnant and lactating women, take note. Now there is one more reason to watch what you put in your mouth: you may be influencing your child's future palate. New research shows that infants exposed to a certain flavor in the womb or through breast milk later enjoyed that flavor when they were ready for solid foods.
It is known that during pregnancy, flavors from the mother's diet are transmitted to the fluid surrounding a developing baby. Since the fetus also swallows this amniotic fluid, it already may be experiencing the typical flavors of a culture's cuisine before leaving the womb. In a similar fashion, the tastes in a mother's diet will also be transmitted to the infant via breast milk.
Researchers at Philadelphia's Monell Chemical Senses Center wondered if this early experience with certain flavors influenced a child's acceptance and enjoyment of similarly flavored food later down the road.
"This study followed from a number of other studies that we have done, where we have shown that the flavor of mother's milk really reflects the diet of the mother. So, human milk really reflects the culture into which the baby is born; it contains all the flavors and spices that the mother is eating," lead author Julie Mennella, PhD, tells WebMD. "And we have been able to show over the years that some of these flavors, too, are being transferred to amniotic fluid."
Mennella is a member of the Monell Chemical Senses Center.
In the study, published in June's Pediatrics, Mennella and collegues looked at whether exposure to the flavor of carrots in the womb or through breast milk affected the acceptance of carrot-flavored cereal when the baby was weaned at 6 months of age.
The researchers recruited 46 women who were in the last trimester of pregnancy and assigned them to one of three groups. Group 1 was instructed to drink a certain amount of carrot juice during the last trimester; group 2 was instructed to drink the carrot juice during the first months of breast feeding; and group 3 was told to drink water and no carrot juice.
About four weeks after the mothers started to give their babies cereal, the babies were videotaped eating plain cereal and, at another time, cereal made with carrot juice. The babies who had been exposed to carrot juice in the womb or through breast milk made fewer 'negative' faces, were perceived by their mothers as enjoying the carrot-flavored cereal more, and they ate a bit more of the cereal.
"When we looked at the video tapes and looked at [the babies'] facial responses, it really implied that [this] exposure to a flavor affects the enjoyment of a food and also the acceptance of that food," says Mennella.
This process of gaining food experiences "...is one of the first ways in which infants are learning about the food choices of the mother." she says, noting there may be regional implications as well. "These flavor experiences in amniotic fluid and mother's milk are the infant's first exposure to the flavor of the foods of their culture.
"There has always been a lot of folklore that babies will like the foods that were craved by the mother during pregnancy," says Mennella. "And I would suggest that it might be the case, if the mother gives in to those cravings, and this is one mechanism that may explain a lot of this."
Linda Bartoshuk, PhD, points to other implications of the study. She is an experimental psychologist, with an expertise in taste, who reviewed the report for WebMD.
"It is advancing our insight into how people like food," says Bartoshuk, a professor in surgery at the Yale University School of Medicine in New Haven, Conn.
"What are the factors that make people like particular foods?" she says. "This shows an exposure factor is involved, which could be incredibly important."
"We have this incredible anomaly: we know what to eat, we know what is healthy and we also know that people don't make those choices," she says. "Why don't they? I don't think there is a more important question to ask in modern medicine, if you are interested in preventive medicine."
"It is so very important to know that so much of what we like to eat depends on our experience, our learning," Bartoshuk says, adding, "There could be a day where we could use that understanding to help people eat better."
Mennella says the study findings shouldn't panic pregnant and lactating women. "Eat the foods that you enjoy," she says. "When you think cross-culturally, it is the foods that really define you as a people. Enjoy them -- this is one of the ways in which you are going to be transmitting this to the next generation."