Food During Pregnancy: How your diet affects your baby's tastesAnnie Paul
The first time I realized I was pregnant, I was standing in the aisle of a supermarket. A week before, I’d taken one of those extra-early pregnancy tests (“Our Most Accurate Results: Five Days Sooner!” read the box), and it had come up negative. Now I was leaning over the sushi case, debating my dinner options – Spicy tuna roll? Salmon and cucumber? – when John, standing beside me, said almost offhandedly, “Hey, did you ever get your period?” I was so persuaded by the authority of the slim pink wand and its austere single line that I had forgotten all about that more traditional indicator. John and I turned slowly to look at each other, a cartoon of dawning awareness. “Oh my god,” I said. Suddenly, a beer-and-sushi run to Whole Foods acquired a weighty new significance. We started our shopping trip all over again, pushing our cart back to the entrance of the store. Now we would be buying, and eating, for three instead of two, and we were determined to do it right.
Almost immediately, things got complicated. Halfway down the condiments aisle, I paused in front of the jars of peanut butter. Peanuts and other legumes are a healthy source of protein, I knew – but hadn’t I read that eating nuts during pregnancy could predispose your child to allergies? We moved on. Rolling to a stop in front of the expansive dairy case, we hesitated again. Everyone knows that cheese is a good source of calcium, important for building strong bones. But I’d heard that soft cheeses, or those made with raw milk, may carry the bacterium listeria, which could cause birth defects or miscarriage. Onward to the chilly realm of the seafood department, where glassy-eyed fish regarded us from their bed of ice. I had a vague recollection that the fatty acids in fish promoted fetal brain development – but also that some fish contained pollutants like mercury and PCBs.
And so it went, as we made our halting way through the store. In a flash, the world of food had been divided into good and bad, harmless and hazardous, and it was up to us to make the correct choices.
No activity of everyday life is so instantly changed by pregnancy as eating. New worries about food safety turn ordinary meals into minefields. Waiters and counter clerks become subject to interrogation: Is the cheese pasteurized? Is the fish cooked through? Is the egg still runny, the meat still pink? More daunting still is the notion that what you eat becomes the very stuff of which your child is made. At times this idea is expressed with almost comic literalness – as when, during my first pregnancy, I signed up to get weekly emails from a parenting website. Each Saturday a message would appear in my inbox informing me of my fetus’s current size, invariably described in terms of something edible. At nine weeks, I learned, my fetus was as big as a grape; at 17 weeks, a turnip; at 19 weeks, a “large heirloom tomato.” The implication was clear: your baby is what you eat, and your baby had better not be the shape of a Twinkie.
The pressure begins even before you conceive a child, of course: already, women are bullied into unhealthy eating habits by images of unattainable slenderness; already, food has been moralized by the fear of gaining weight: carrot sticks and low-fat yogurt are “good,” cookies and chocolate are “bad.” Now, during pregnancy, food poses a threat not only to one’s waistline but to the health of one’s future child. It doesn’t take much imagination to see that this research could be used to add maternal guilt to the heavy emotional freight already borne by food. I think of an actual headline I spotted in the magazine U.S. News and World Report: “Don’t Eat That, or Your Child May Grow Up Fat.” Once again we’re told that pregnant women are a danger to their fetuses, each bite they take a time bomb on a fork.
But there’s another way to think about eating during pregnancy: as an act of sharing, even of teaching. Research suggests that more mature fetuses can experience tastes and smells in the womb; by seven months, the fetus’s taste buds are fully developed, and its olfactory receptors appear to be functional. The flavors of the food a woman eats find their way into the amniotic fluid, which is continuously swallowed by the fetus. Babies seem to remember, and prefer, these familiar tastes once they are out in the world. In a 2001 experiment conducted by Julie Menella, a psychobiologist at the Monell Chemical Senses Center in Philadelphia, a group of pregnant women was asked to drink carrot juice during their third trimester; another group of pregnant women drank water instead. Six months later, the women’s infants were offered cereal mixed with carrot juice, and their facial expressions were videotaped while they ate. The offspring of the carrot juice-drinking women consumed more carrot-flavored cereal than babies who had not been exposed to the stuff before birth, and appeared to like its taste more.
Indeed, studies conducted with a variety of mammalian species demonstrate that young animals prefer flavors they encountered during gestation and lactation. Young rabbits devour the aromatic juniper berries their mothers ate during pregnancy; wild mice feast on fennel like that consumed by their dams; baby lab rats love the chocolate, rum and walnut flavors fed to their mothers by experimenters. Such preferences are highly adaptive, Mennella tells me. “Mothers are giving information to their offspring through what they consume during pregnancy and breastfeeding, telling them: This is what’s good and safe for us to eat,” she says. Among humans, such messages may be even more profound, bearing meaning not only about safety, but about culture. The characteristic flavors and spices of particular cuisines are likely introduced before birth, a prenatal initiation into one of culture’s most powerful expressions: food. “When a baby is born, he is not a blank slate,” says Mennella. “He has already been shaped by a rich array of sensory experiences that we are only now beginning to understand.”
Adapted from Origins: How the Nine Months Before Birth Shape the Rest of Our Lives by Annie Murphy Paul, published in September by Free Press.