The Newborn Senses: Taste & Smell

Science points to a powerful fact: babies are wired for remembering smells from before birth. And experiencing these same familiar smells after birth help newborns quickly form preferences outside the womb that help them bond, find food, and feel secure. But newborns are not only attracted to familiar scents.  Scientists have also found that when newborns smell something unfamiliar, the odors activate the same regions of the brain that are active in adults — showing just how ready they are to experience new things and explore the world around them through scent.⁹

A familiar smell can both comfort a baby and help ease pain. For example, the scent of breast milk seems to have a calming, painkilling effect on newborns. However, this only worked if the breast milk came from their own mother.¹⁰ This is not just because breast milk is the baby’s primary food source. When newborns have their heels pricked for blood tests, studies have found that those who smell their mother’s breast milk cry less and have less stress hormones than babies who are bottle-fed and exposed to the scent of their usual formula.¹¹ There is something uniquely comforting about maternal smells. Even the gentle scent of vanilla has been shown to calm premature infants — but only if it’s a smell they already know.¹² In another study, babies didn’t show a rise in stress hormones when their blood was drawn in the presence of soothing scents like lavender or a synthetic milk odor.¹³ These findings suggest that smell isn’t just a source of comfort — it is also a simple, natural tool for helping babies cope with pain.

Flavor is more than just taste — it’s a combination of what the tongue senses and what the nose smells. Our tongues detect five basic tastes: sweet, sour, bitter, salty, and a savory, brothy flavor called umami . Newborns respond to all of these — except salt — from the very beginning.¹⁵

In fact, babies show strong reactions to different tastes. Give a newborn something sweet or savory, and you might see happy signs like rhythmic tongue movements, lip smacking, or even a little smile. But offer something bitter, and a newborn’s face tells another story — grimacing, wrinkling their nose, or even flailing their arms in protest. Sour flavors get mixed reviews, usually with puckered lips and a few confused expressions.^{16 17 18}

Long before the first spoonful of mashed peas, babies are already getting a “preview” of the foods their family eats. Evidence shows that flavors from a mother’s diet pass into the amniotic fluid during pregnancy and later into her breastmilk after birth. These flavors peak in breastmilk about 1½ to 3 hours after mothers eat flavorful foods, giving babies regular exposure to the family’s typical diet.²¹

Science shows that early exposure to flavors in the mother’s milk affects the foods they choose later in life. Babies who taste certain flavors in the womb — like garlic, carrot, or vanilla — are more likely to accept those foods when they’re introduced later as solids.^{23 24} Studies show that breastfed babies respond to the changing flavors in their mother’s milk by adjusting how long and how eagerly they feed.²⁵ Later on, breastfed babies are often more accepting of fruits and vegetables if their mothers regularly ate those foods themselves.²⁶

Scientists have also studied food preferences in babies who drank formula. In the U.S., there are two major kinds: cow’s milk formula and a hypoallergenic formula with a strong bitter and sour taste. Babies who were fed the more bitter hypoallergenic formula were more likely to enjoy sour or bitter foods like sour apple juice, unsweetened cereals, and vegetables like broccoli — even years after their last sip of formula.^{27 28}

The takeaway? What babies taste in the womb, through breastmilk, or in formula helps shape their food preferences for years to come.