Researchers in England have recorded direct evidence for the first time that babies react to different smells and tastes during pregnancy, by analyzing their facial expressions.
- During pregnancy, a balanced, alcohol-free diet is strongly recommended. Certain foods are to be preferred because they provide essential vitamins and nutrients for the baby: folate or vitamin B9 at the start of pregnancy, then calcium, vitamin D, iron, carbohydrates in particular.
- Accustoming babies to healthy food flavors during pregnancy could influence their preferences once born, the researchers of this new study hypothesize.
Researchers have observed how fetuses react to the taste of carrots or kale right after their mother ingests them. Fetuses exposed to carrot flavors showed more smiling facial expressions while those that tasted kale showed more sad expressions. Spectacular reactions that the researchers had the joy of sharing with future parents.
Taste, smell: better understand their development in humans
These are the results of a study conducted by the Fetal and Neonatal Research Laboratory at Durham University, UK, which was published in the journal Psychological Science. 4D ultrasounds of 100 pregnant women between the ages of 18 and 40 were carried out to see how the babies react to the different flavors of food eaten by their mothers. Ultrasounds were performed at 32 weeks and 36 weeks of pregnancy.
The mothers received a single capsule containing approximately 400 mg of carrot powder or 400 mg of kale approximately 20 minutes before each analysis. They were asked not to consume any food or flavored drink one hour before their examination. The facial reactions seen in both groups exposed to these flavors, compared to fetuses in a control group that were not, showed that exposure to a small amount of carrot or kale flavor was sufficient to stimulate a reaction.
Their findings could deepen our understanding of the development of taste and smell receptors in humans. Humans experience flavor through a combination of taste and smell. In fetuses, it is thought that this could occur by inhaling and swallowing amniotic fluid in the womb.
Taste preferences influenced by the mother’s diet?
The researchers say their findings could also help educate mothers about the importance of taste and healthy eating during pregnancy. Indeed, they speculate that the food choices of pregnant women could influence the taste preferences of infants after birth and potentially have consequences for the baby’s future eating habits. For the fetus, repeated exposure to certain flavors based on what the mother regularly eats could lead to long-term taste preferences. For example, expectant mothers could accustom their unborn child to “less preferred” flavors of healthy foods like kale even before they are born.
But that remains a hypothesis. The next step is to examine whether fetuses show fewer negative responses to these flavors over time. This would mean that repeated exposure to a certain flavor would lead to greater acceptance when babies taste them for the first time after birth.
A new follow-up study with these same babies has also been undertaken to see if the influence of flavors on the fetus affects their acceptance of different foods after birth.
