Dec. 10, 2021 -- They say you are what you eat, but scientists have long wondered whether breastfeeding babies are what their mothers eat, too. Their question: How much of a nursing mother’s diet eventually plays a role in a child’s food preferences later in life?

The aroma, taste, and makeup of breast milk changes from day to day, based mostly on the mother’s diet. But previous research has already shown that the foods a mother eats do not directly translate into the same smells and tastes of that food in breast milk. Some substances from the mother’s diet enter her breast milk, some don’t, and even ones that do may have a different scent or flavor than what the mother experiences.

Spice in Breast Milk Could Shape Taste Preferences Later

But a new study suggests that the active ingredient in black pepper makes its way into breast milk and may help the infant develop a tolerance to pepper later. The researchers published their findings in the journal Molecular Nutrition and Food Research.

Pinch of Pepper

The study authors thought that maybe some food preferences could result from sensory programming that occurs through breast milk in the first few months of life. Though past studies have looked at which odor-producing substances transfer into breast milk, not many have explored specific substances that give food its distinctive flavor, or even what makes up the taste of breast milk. So they decided to investigate what happens when a mother consumes a meal containing three specific compounds: those that give pepper, chili, and ginger their particularly pungent flavors.

The researchers recruited 18 healthy, nonsmoking, nursing mothers who were producing more than enough milk for their baby’s needs. Their breastfeeding children ranged in age from 8 weeks to 1 year old. The women all ate a curry dish after having spent 2 days avoiding onion, garlic, and the spices in the curry. Then they provided pumped breast milk samples at 1, 2, and 3 hours after eating the curry.

Within an hour of the women eating the curry, the scientists were able to detect piperine, the compound that gives black pepper its bite, in the mothers’ breast milk. They did not find the compounds from ginger, chili, or curcumin -- the main active ingredient in turmeric -- in the breast milk. The piperine remained there for several hours, but there wasn’t enough for an adult to be able to taste it. It wasn’t possible to reliably tell whether the infants could consciously detect the flavor, but the researchers don’t think it’s likely they did.