Arsh Raziuddin / The Atlantic

Every couple of months, a 21-year-old Chicagoan named Erynn Nicholson will scoop some vanilla ice cream into a bowl, crumble a fistful of Ruffles potato chips on top, and then mix it all together. Then she’ll call or text her mom. "I always let her know I’m eating our snack,” she told me.

Ice cream with potato chips has been their snack since before Nicholson was born—when she was still in the womb, her mom ate it regularly. The dish has carried special meaning for her for as long as she can remember, and while it’s not her “favorite favorite” food, “it's in its own little category,” she said.

That category, for many like Nicholson, transcends a mere flavor preference: Some people’s fondness for the foods their mother craved during pregnancy can to them seem predestined, taking on an almost sacred status in the mother-child relationship. Research hasn’t identified a direct causal link between the diets of pregnant women and the lifelong food preferences of their children, but exposure to certain flavors in the womb is one factor, among many, that can shape what people like to eat.

"Your sense of taste and smell is developed in utero,” says Julie Mennella, of the Monell Chemical Senses Center, in Philadelphia. “What the mother eats, a lot of [the flavors]—the garlic, vanilla, carrot, anise, a whole host of different flavors—are transmitted through the bloodstream and flavor amniotic fluid … If a baby has experienced a flavor in utero or in breastmilk, they prefer it more." Fetuses can get a lot of exposure to whatever flavors their mother recently tasted—near the end of a pregnancy, they can swallow almost a liter of amniotic fluid a day.

These early flavor encounters can shape palates after birth. One study in which Mennella and other researchers randomly assigned some of their subjects to drink carrot juice daily in the last few months of pregnancy or after birth, during lactation, found that those women’s children had a stronger preference in infancy for the flavor of carrots than the babies of women who were instructed to avoid carrots and drink water. Another study that had pregnant women eat garlic found a similar effect that persisted into the children’s adolescence.

That said, people develop flavor preferences in many other ways—maybe they were fed a certain food repeatedly as a baby, or observed their parents, siblings, or friends enjoying it during childhood. So even if a taste one has for, say, ice cream and potato chips mirrors one’s diet in the womb, the latter may not have been solely responsible for the former. “When you look at ‘My mother craved this; I like that’—that's association. That doesn’t tell you cause and effect,” Mennella said. “If the mother likes the food and the child accepts the food, they will continue to be fed it, strengthening the preference.”

Whether there’s a biological cause or not, the foods that mothers eat during pregnancy can be imbued with lasting meaning for their children. Layma Murtaza, who works in international development in Washington, D.C., and Kabul, Afghanistan, told me that her mother had a predilection for toasted cheese sandwiches during pregnancy—which Murtaza only learned roughly a decade ago, when she was in her early 20s, after a childhood of enjoying the sandwiches two or three times a week.

Even though she eats much less bread now, the food remains special to her because of what it meant to her mom. “That’s what gave my mother comfort while she was pregnant, and I was her first child,” she said. “I think anything that makes her comfortable is something that makes me happy.”

Ice cream and potato chips inspire similarly warm feelings in Nicholson. "Now that I’ve been in college and away at school and not with my mother every day, sometimes when I eat it I get nostalgia [for] my childhood,” she said. “It makes me think about my mom. It makes me miss her.”

Mennella thinks that this narrativizing is quite powerful. “When these individuals are retelling these stories, it's really bringing them to their past, to their beginning,” she said. “It's the formation of who they are." Whether treasured prenatal foods are treasured because they were among the first flavors someone ever tasted or because warm familial feelings later gave them a mythic status is beside the point: Above all, these foods are something a mother and child shared when they were closer than they’d ever be again.

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