Babies respond positively to smell of foods experienced in the womb, according to university study
Babies show positive responses to the smell of foods they were exposed to in the womb after they are born, according to a new study.
The findings, led by Durham University, UK, could have implications for understanding how healthy eating habits might be established in babies during pregnancy.
The research included scientists from Aston University, UK, and the Centre national de la recherche scientifique (CNRS) and University of Burgundy, France. It is published in the journal Appetite.
Researchers analysed the facial expressions of babies who had been repeatedly exposed to either kale or carrot in the womb after birth.
Newborns whose mothers had taken carrot powder capsules when pregnant were more likely to react favourably to the smell of carrot. Likewise, babies whose mothers had taken kale powder capsules while pregnant reacted more positively to the kale scent.
Research co-lead author and supervisor Professor Nadja Reissland, of the Fetal and Neonatal Research Lab, Department of Psychology, Durham University, said: “Our analysis of the babies’ facial expressions suggests that they appear to react more favourably towards the smell of foods their mothers ate during the last months of pregnancy.
“Potentially this means we could encourage babies to react more positively towards green vegetables, for example, by exposing them to these foods during pregnancy.
“In that respect, the memory of food the mother consumes during pregnancy appears to establish a preference for those smells and potentially could help to establish healthy eating habits at a young age.”
This study is a follow-up to a 2022 research paper where the researchers used 4D ultrasound scans at 32 and 36 gestational weeks to study foetal facial expressions after their pregnant mothers had ingested a single dose of either 400mg of carrot or kale capsules.
Foetuses exposed to carrot showed more “laughter-face” responses while those exposed to kale showed more “cry-face” responses.
For the latest study, the researchers followed up 32 babies from the original research paper – 16 males and 16 females – from 36 weeks gestation until approximately three weeks after birth.
Mothers consumed either carrot or kale capsules every day for three consecutive weeks until birth.
When the babies were about three weeks old, the research team tested newborns’ reactions to kale, carrot, and a control odour.
Separate wet cotton swabs dipped in either carrot or kale powders, or water as the control, were held under each infant’s nose and their reaction to the different smells was captured on video.
The babies did not taste the swabs. Scientists then analysed the footage to see how the newborns reacted and compared these reactions with those seen before the babies were born to understand the effects of repeated flavour exposure in the last trimester of pregnancy.
The research team found that, from the foetal to newborn period, there was an increased frequency in “laughter-face” responses and a decreased frequency in “cry-face” responses to the smell the babies had experienced before birth.
Humans experience flavour through a combination of taste and smell. In foetuses, this happens through inhaling and swallowing the amniotic fluid in the womb.
Research co-lead author Dr Beyza Ustun-Elayan carried out the research while doing her PhD at Durham University.
The research involved the children of white British mothers, and the researchers say that future studies should be widened to explore how different cultural dietary practices might influence foetal receptivity to a broader array of flavours.
Research co-author Professor Jackie Blissett, at Aston University’s School of Psychology, said: “These findings add to the weight of evidence that suggests that flavours of foods eaten by mothers during late pregnancy are learnt by the foetus, preparing them for the flavours they are likely to experience in postnatal life.”
Visit HERE to read the full research paper in Appetite.
