Unborn Babies Respond to Flavors From Foods Their Mothers Eat, Study Reveals

A new study, titled "Flavor Sensing in Utero and Emerging Discriminative Behaviors in the Human Fetus" published in the journal Psychological Science, claims that unborn babies react to taste and smell in the womb.

Scientists used 4D ultrasound scans of 100 pregnant women to see whether fetuses will respond to flavors from foods that the mothers eat. They identified fetal facial reactions to kale and carrot flavors. This is the first direct evidence that unborn babies react differently to smells and tastes.

Unborn Babies Respond to Flavors From Foods Their Mothers Eat, Study Reveals Pexels/Pavel Danilyuk

Facial Reactions A Fetus Makes on Certain Tastes and Smells

The new study discusses how fetuses experience the flavor, Science Daily reported. Whereas humans experience it through a combination of taste and smell, fetuses are previously thought to experience it through inhaling and swallowing amniotic fluid inside the womb.

Lead researcher Beyza Ustun from Durham University said that there is plenty of research that suggests babies can taste and smell in the womb, but most of them are post-birth outcomes. On the other hand, the new study is the first to discuss these reactions when babies are still fetuses.

The international team of researchers scanned 100 pregnant women at both 32 and 36 weeks of their pregnancy to see fetal expressions of kale and carrot flavors. Each mother was given a capsule that contains 400mg of carrot or 400 mg of kale powder 20 minutes before they are subjected to the 4D scan.

They are not allowed to consume any food or flavored drinks an hour before the scan. Also, they are not allowed to eat or drink anything with kale or carrot flavors on the day of the scan to eliminate factors that might affect the results.

They found that just a small amount of carrot or kale flavor is enough to elicit a reaction from the unborn babies. They found that fetuses exposed to carrot flavor responded with a "laughter face," while those exposed to kale flavor had "cry face" responses.

Findings Highlight Importance of Taste and Healthy Diet During Pregnancy

Co-author Professor Nadja Reissland also from Durham University said that 4D ultrasound scans were usually used to monitor fetal reactions to see how they respond to maternal health behaviors. This study helped them understand the implications of fetal abilities in sensing and discriminating different flavors and smells that their mothers eat.

The result of repeated exposure to certain flavors before birth could influence the food preferences of babies post-birth, Neuroscience News reported. Ustun noted that this is important to know, especially when advocating healthy eating for pregnant women and avoiding food fussiness when weaning.

The study is the latest research that has important implications for understanding the abilities of a fetus to discriminate flavors and smells from its mother's diet.

Co-author Professor Benoist Schaal, of the National Center for Scientific Research-University of Burgundy in France, said that the official expressions of the fetus say that certain chemical stimuli pass through the maternal diet into the fetal environment. The findings might help mothers to know the importance of flavor and healthy diets during pregnancy.

The team is now on the follow-up study that looks at whether the same babies post-birth are influenced by the flavors they had while inside their mother's womb.