Prenatal Diet Sets Food Preferences
If the smell of beets makes you gag but you simply can't get enough sour crème and chive potato chips, your Mom may be to blame -- and not because of what she fed you growing up. Several studies show that food preferences may be set even before you're born, as early as 13 weeks after gestation. And those food preferences derive from what your Mom ate while you were in the womb.
The process is called "food imprinting," and it works because the scent and flavor of what a pregnant woman eats passes into the amniotic fluid. The fetus ingests that amniotic fluid starting at 12 weeks, and apparently, develops taste preferences based on that experience.
To verify that particular foods eaten by mothers affect later preferences of the baby, researchers at the Monel Chemical Senses Center in Philadelphia had pregnant women in their final trimester drink carrot juice four days a week for three consecutive weeks. Six months later, the babies of these women preferred carrot-flavored cereal to other varieties and made fewer unhappy faces when exposed to carrot cereal than babies who had not had prenatal carrot juice. They also consumed 20 percent more carrot-flavored cereal than babies who didn't have exposure to carrot juice in utero.
A series of similar studies have found parallel results. When mothers consumed lots of peaches during pregnancy, their babies preferred peaches after birth. When nursing mothers ate green beans in large quantities, their babies developed a lasting love of green beans. Similar studies in Europe found that women who consumed plenty of garlic during their pregnancies had babies who enjoyed garlic, and a French study found anise-consumption by pregnant moms imparted a love of anise to their offspring.
"So what that tells you is that there's some type of memory that's being formed," said Dr. Julie Menella, director of the carrot-juice study. That's also the premise of a new book called Feeding Baby Green by pediatrician Dr. Allen Greene. Dr. Greene contends that babies remember the tastes they experienced in the womb and seek them out after birth. He cites a study published in 2008 in the Journal of Physiology in which pregnant animals were divided into two groups: one that ate healthy foods and another that ate fatty, sugary, salty foods including donuts and chips. After giving birth, the offspring that had been exposed to healthy diets in utero wanted healthy foods, while the junk food fetuses turned into junk-food junkies with far more health problems than the animals that came from parents with healthier diets.
(Thank goodness no major food company has yet undertaken a study to discover if brand preferences can be set before birth -- if one can cultivate "Kelloggs babies," for instance, as opposed to "Post babies.") Anyway, if a mother can't get past pickles and ice-cream while pregnant, there's still hope of salvaging the baby's food tastes as long as the mother acts quickly after giving birth. Dr. Menella says that what mothers eat while nursing their babies impacts the child's food tastes, too. In fact, what a child eats in the first seven months of life, combined with the mother's food intake in the last few months of pregnancy, sets that child's food preferences for life. Or to put it another way, regular meals of Hamburger Helper, Diet Pepsi, and Ding Dongs while pregnant are probably not in your baby's best interest.
And as I was saying, this advice also extends to nursing mothers as babies who nurse will probably have more diverse food preferences than babies fed formula. This is because breast milk contains traces of whatever mom has eaten and the baby imprints those various flavors. Formula, on the other hand, has a fixed blend of flavors, exposing the child to limited tastes. The experts suggest that pregnant and nursing moms should eat plenty of diverse fruits and vegetables if they want their children to grow up making wise choices.
They should also avoid drinking, as most pregnant women and nursing mothers know -- but now for another reason. Studies have found that rodents exposed to alcohol in utero prefer alcohol-flavored water after birth. Other studies have found a connection between prenatal alcohol exposure and alcoholism later in life. And as described above, a yearning for junk food can be passed on, so pregnant and nursing moms would do well to avoid sugar and unhealthy fats as assiduously as they avoid beer and margueritas. It's also something to think about when choosing a formula for your baby if you're bottle feeding. In many formulas, sugar or corn syrup is either the first or second listed ingredient.
That's especially true because babies naturally prefer sweet tastes, and given limited exposure to other tastes they can easily evolve into sugar junkies. According to Dr. Leann Birch, chair of Pennsylvania State University Department of Health and Human Development, fetuses increase the rate at which they ingest amniotic fluid when a sweet taste is present. Vegetables tend to taste bitter to babies, and so they naturally prefer fruits, but exposing the children to vegetables from before birth can ameliorate that tendency.
The trick is to be consistent. If mom eats a carrot every other week it isn't going to turn junior into a vegan after birth. By the same token, an ice-cream cone enjoyed by Mom every other month probably won't lead to baby's first words being "Cherry Garcia." As Dr. Birch says, "[F]or an infant to interpret a food as same and acceptable, there has to be repeated exposure -- particularly when you get to fruits and vegetables that aren't naturally sweet"
The side benefit to eating well during pregnancy and lactation, of course, is that mom also gets healthy. But if mom herself was exposed to too many cookies and cakes and convenience foods before her own birth, she may have a difficult time giving up the foods she craves for the duration of her pregnancy -- the foods she's been imprinted to -- even though she knows the potential benefits to her offspring and herself. And so the cycle continues, with each generation getting fatter and unhealthier than the previous.