The study, published in the scientific journal Developmental Psychobiology, involved researchers at universities in the UK, France and the Netherlands.
Initially, 34 fetuses were followed; they were exposed to either kale or carrots in weeks 32 and 36 of pregnancy. The mothers then continued to take capsules with either kale or carrot powder several times a week until delivery.
The children were then followed up at approximately three weeks of age and again at three years of age, when twelve of them remained in the study. Their facial reactions were examined in the fetal stage by ultrasound and after birth from video recordings.
Reacted differently
The researchers found that children exposed to carrots before birth showed less negative reactions when they were later exposed to the smell of carrot, but grimaced at the smell of kale. Corresponding reactions were seen in children exposed to kale.
"What we see over time is that children still respond more favourably to vegetables that they were exposed to in the womb. This could suggest that exposure to a particular flavour late in pregnancy can create a long-lasting taste or smell memory that could potentially influence their food preferences years after birth," Nadja Reissland, a professor at Durham University and the study's lead author, told The Guardian.
More studies are needed
However, the researchers emphasize that the group studied is small and that more and larger studies are needed to investigate whether the effect has any significance for children's actual consumption of vegetables.
They also highlight that the children may have been exposed to the flavours via breast milk in the weeks after birth, and that genetic differences in smell and taste perception may have influenced the results.
