What a mom-to-be eats during pregnancy not only nourishes her baby in the womb, but may shape food preferences later in life. Starting around the 21st week of pregnancy, babies' taste buds are developed enough to detect flavors that end up in amniotic fluid as a result of their mothers' diets. As babies busily gulp down their main form of nourishment, scientists from Monell Chemical Senses Center say the flavors they are being exposed to provide "food memories," an important part of how the human palate and food likes and dislikes are formed.
Amniotic fluid is most likely to pick up certain flavors. "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," Dr. Julie Mennella, a researcher at Monell, tells National Public Radio.
Just how important are these in-utero food memories for developing a baby's palate? Dr. Mennella and her colleagues had one group of women drink carrot juice daily throughout their pregnancies and another during breastfeeding only, reports Canada's Globe and Mail. Another group was to abstain from carrots altogether. When babies started eating solid foods (around 6 months), researchers fed them cereal made with carrot juice and videotaped babies' responses.
"Babies who had experienced carrot in amniotic fluid or mother's milk ate more of the carrot-flavored cereal," and made fewer "negative faces while eating it," says Dr. Mennella. Facial expressions that say "Yuck," she speculates, could be a reaction to unfamiliar tastes—the willingness of other babies to gobble up carrot juice may good proof that they recognize it as a food they've eaten before.
Developing a taste for a mother's diet makes sense, Mennella tells NPR, 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," she finds.
For example, if you regularly eat broccoli during pregnancy, once solids are introduced, your baby may be more likely to say "Yummy!" after eating broccoli than another baby whose mother skipped the cruciferous vegetable. The research could also help explain why kids from countries with spicy foods and adventurous menus enjoy more diverse foods than a child exposed to such American staples as peanut butter and jelly sandwiches.
Another scientist, University of Florida taste researcher Linda Bartoshuk, agrees with Mennella's findings, telling NPR, "To what extent can we make a baby eat a healthier diet by exposing it to all the right flavors—broccoli, carrots, lima beans, etc.? Could we do that or not? My guess is we could."