Rare ultrasound images show babies in the womb smiling while their mothers eat carrots

We’ve got a fun and fascinating science-based story for you, baby lovers and kale haters.

A new study published in Psychological Science shows rare up-close-and-personal photos of babies in the womb reacting to various foods their mothers eat. Previous research with infants and breastmilk has shown that flavors are transmitted from mother to child via amniotic fluid, but this is the first time that unborn babies have been studied.

One hundred pregnant women from the United Kingdom were given powder with either carrot or kale flavoring or no flavoring at all. After 20 minutes, 4D ultrasound scans revealed noticeably different—and somewhat amusing—facial reactions. It was clear which flavors made people smile and which didn’t.

The carrot flavor, as shown in the image below, induced a smiling “laugh face,” as the study dubbed it.

This expression of delight could be due to a preference for sweetness, which newborns are known to gravitate toward as a basic biological driver.

According to the study, this natural instinct may develop long before infancy. And for some of us (including myself), that sweet tooth never truly goes away.

Meanwhile, babies who tasted the kale flavoring made disgusted grimaces, also known as “cry faces.”

Kale wasn’t just difficult to sell to the fetuses; one of the other reasons researchers used capsules rather than raw kale or kale juice was that the mothers couldn’t stand the taste and had such a negative attitude toward it that scientists feared it would influence their babies.

“I had a number of people in the lab, and I tried to give them a kale juice to drink, and you should have seen the expressions,” Nadja Reissland, co-author of the study and head of Durham University’s Fetal and Neonatal Research Lab, told NBC News.

If a picture is worth a thousand words, this one simply says “yuck” over and over.

To be fair, those scowls “might just be muscle movements reacting to a bitter flavor,” according to Reissland, rather than any genuine expression of emotion, adding that expressions become more complex over time during gestation.

The main takeaway from this study (aside from a good belly laugh) is seeing how flavors can influence early humans. If they are exposed to certain foods early in pregnancy, they may embrace them and develop healthier eating habits after birth.

“If we can actually get [children] to like green vegetables and to perhaps not like sweets that much, it might help with regard to their weight gain and their weight balance,” Reissland said.

Almost everyone has at least one vegetable that they adore. Carrots and corn, on the other hand, tend to be on the sweeter side. Bitter-tasting ones rarely excite children, or adults for that matter. Brussels sprouts are particularly reviled.